Yard & Garden: June 19, 2020

This is the Q&A for the Yard and Garden show for June 19, 2020. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 31, 2020. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: John Porter, Extension Educator, Douglas & Sarpy Counties

1. The first question of the show was from a walk-in listener. He had a dwarf Aberta spruce tree that was shooting out long stems of larger growth that didn’t look like the original plant. What is wrong with it?

A. This is reversion. Dwarf Alberta spruce commonly reverts back to the blue spruce parents. The dwarf Alberta spruce actually came from cuttings and grafted trees from a mutation in the original spruce tree. It is unusual growth in the main plant that the plant breeders have taken to make a new tree that is new and interesting. However, even after years of maintaining those traits, another genetic mutation can occur sending it back to the original parent growth of larger and faster growing. Those reverting parts, or large, wild growing branches should be pruned back or eventually the tree will look mostly like the general blue spruce or white spruce.

2. A caller has red raspberries that have been established for 7-8 years. Now the patch has a lot of grass growing in among the raspberries. How can the grass be controlled?

A. Mulch will be the best option for this area. Red raspberries grow upright so they don’t shade out the weeds as much as black raspberries. Glyphosate or Roundup can be used carefully around the plants as well. Use some type of a barrier between the grass and raspberries if sprayed or use a sponging type of applicator or paint it on the grass.

She also wondered what to do with the old canes of the raspberry plants. Should they be cut out?

A. Yes, remove them. Raspberries have perennial roots but the canes are biennial. The first year of growth for a cane is to grow the leaves, the second year is when that cane produces berries, then after that the cane dies out. Canes should be removed during the dormant season after they have fruited.

She also has peony plants and would like to know when is best to prune those back?

A. Peonies should be left to grow throughout the year and cut back in the fall after they turn brown. They need the leaves to grow throughout the summer months to build sugars for the roots so they can bloom well next year. The flower stalks can be removed, but the leaves should be left to grow until fall.

3. A caller has blackberries growing in a garden space in the middle of his native grass prairie area. There are now canes coming up and spreading throughout the prairie. How can those be controlled?

A. Blackberries will send out runners from the main plant. These runners are still connected by underground roots, rhizomes, so spraying a chemical on them could kill the main plant as well. It is best to just dig out the plants in the grass. You could use glyphosate or Roundup on the runners, but you would need to cut the runner first to cut the tie to the main plant.

4. This caller has spruce trees that have the tips of the branches dying and those tips are hooked over like a shepherd’s crook. They also have one that the top has died. What is wrong with these trees?

A. The tips of the branches look like the damage from a disease called sirococcus. To control Sirococcus shoot blight, apply a fungicide such as chlorothalonil (Daconil, Bravo) when new shoots are ½ to two inches long, typically in May; and repeat every 3 to 4 weeks if frequent rains occur. For more information, visit this Nebraska Forest Service publication on Diseases of Evergreen Trees. You would be a little late to spray now for this year, but could treat it next spring.

As for the top dieback, that is likely canker, a common disease in spruces. You will have to cut 6-8 inches below the dead area to get rid of that. This will remove the apical dominance in your tree and cause it to grow wider rather than upright. You can train a new leader by keeping one shoot growing more upright and taller than the others.

5. Is there a certain pH that is recommended for vegetable gardens?

A. The general recommendation is to have a pH close to neutral which is 7.0 The best growth from a vegetable garden is when the pH is 5.8-6.5 Below 5.5 or above 7.5 generally requires soil modification. To get the pH you can get a soil sample kit from your local Extension Office and send it in with a sample from your garden. For more information on how to do a soil sample, visit this NebGuide For more information on fertility requirements for your garden, visit this NebGuide

She also wondered about cedar apple rust and what to use to treat the cedar trees from this?

A. It is not necessary to treat cedar trees for cedar-apple rust because the galls on the trees do not harm the tree. If you have susceptible apple trees nearby, those should be sprayed when the orange galls are seen on the trees.

6. When is the best time to transplant roses?

A. Late fall is the best time to move roses, after they have gone dormant. They can be difficult to move, so be sure to take as much of the rootball as you can get.

How can you kill scrub trees growing around the roses?

A. Cut the trees off and paint the stump with glyphosate, or Roundup. You could also use the ‘Glove of Death’ method. This is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the stem and leaves of the trees to kill them.

7. How can you manage grass in the vegetable garden?

A. Mulch would be the best option. No pesticides are labeled for use in the home garden without a Restricted Use pesticide license.

8. This caller has pampas grass that has grown large and now has a dead center. What can he do to get rid of the dead center?

A. The best option would be to dig up he pampas grass and divide it and then replant the new sections. This will eliminate the dead center. The fall would be the best time to do this.

9. A caller has a maple tree that was planted 3 years ago. Last year and again this year it has leafed out but the top third of the tree will lose all the leaves early in the summer and never regrow those leaves. What is wrong with it?

A. Unfortunately, it is likely that this tree is dying and will not recover. This is most likely caused by a root issue. A large root may have been injured when it was transplanted to this location or it could have a root rot issue. After discussions, she was watering the tree all night once a week. This is too much water for the tree. A newly planted tree would have a small rootball and would only need to be watered for about 20-30 minutes once a week, even a full grown tree would only need to be watered for about an hour at the slow trickle method. This tree was likely sitting in water for a few days after this long watering which would have caused the roots to rot and this will cause dieback from the top of the tree first followed by full tree death. It would be best to remove this tree and start over.

10. This caller has a pin oak tree with branches that hang over the sidewalk. When can she prune it and where should she prune the branches?

A. Oaks are prevalent to a disease caused oak wilt that is caused by a beetle spreading the disease when it feeds on a tree. The beetles are attracted to wounded trees, pruning the tree causes a wound. Because of this, oaks should not be pruned in the summer months. They are best pruned in the later fall. Prune back to the trunk, just outside of the branch collar. If you don’t want to cut all the way back, you can cut back to a side branch that is at least 1/2 the size of the branch that is being removed. Do not just cut to a random location in the middle of the branch.

11. A caller has thistles in her pasture. She went out to cut them the other day and noticed something had been feeding on the thistles. What was that?

A. There are some insects used to manage thistles, the thistle tortoise beetle is one. It is likely that this was feeding on the thistles which will help to control the population of the thistles.

12. This caller has 12 tomatoes, 2 of them have curling leaves at the top of the plant. What is causing this?

A. Unfortunately, we aren’t completely sure what is causing this damage, but it is widespread throughout the whole state this year. It could be from herbicide damage due to chemicals still being used later in the year with the cooler spring and sudden change of temperatures to very hot. There is also thought that it could be from the beet curly top virus. This could also be from watering issues such as over watering or underwatering. It would be best to just pull the plants out because if it is the virus it can spread to the other plants and if it is herbicide injury the produce would not be safe to consume. If the other plants look ok, this would be the best option. This condition is one that is being constantly discussed in Nebraska Extension this year.

13. The final caller of the show has an American Elm tree that 1/2 of it has leafed out and the other half has died. What is wrong with it?

A. It is likely that this plant has Dutch Elm Disease, just like the elm we discussed on the show last week. There is no control or prevention for this disease. American elms were mostly wiped out in the 1960’s due to this disease but a few have survived or came up naturally. The American elms that are still alive will eventually die due to the disease, it will get to them. He can send a sample into the UNL Plant Pest Diagnostic lab for confirmation, but if it is Dutch Elm disease, the tree should be removed.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Yard & Garden: June 12, 2020

This is the Q&A for the Yard and Garden show for June 12, 2020. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 31, 2020. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: No guest host due to COVID-19 and social distancing

1. The first caller of the show has tomatoes that only grew to about 1 foot tall and then they died back from the top. What is wrong with them?

A. It could be that they need to be watered more effectively. He has the plants mulched with grass and is watering, but just using a hose-end sprayer. When just watering with a hose like that the top couple inches of soil get wet then it spreads out rather than down, so the plants aren’t getting enough water to their roots. It could also be from a disease, but it is hard to tell from just a description.

2. A caller has watermelon radish plants that are going to seed. Can she cut the flower stalks off so they continue to grow? The radishes are not very large yet.

A. These plants are not going to grow much longer. When we get to hot weather the cool season crops will go to seed or bolt and will not live long, radishes are one of those plants. She said she had to replant later in the year due to frost damage in late April/early May, that is just too late to plant radishes for a good crop. She could try again in the fall or plant earlier next spring.

3. A caller has an American elm tree that has a few branches that are dying off. He has cages of rabbits underneath the tree and wondered if too much nitrogen was being applied to the roots or if the roots are reaching up to under the chicken coop with high nitrogen?

A. It is more likely that this tree has developed Dutch Elm Disease and will likely die. There is no control or prevention for this disease. American elms were mostly wiped out in the 1960’s due to this disease but a few have survived or came up naturally. The American elms that are still alive will eventually die due to the disease, it will get to them. He can send a sample into the UNL Plant Pest Diagnostic lab for confirmation, but if it is Dutch Elm disease, the tree should be removed.

4. This caller is actually from Oklahoma, but was doing work in the area to call in. He was wondering what we do for squash bugs?

A. Squash bugs can be difficult to control in a garden and most of the time once they are in your garden, they will always be there. For chemical controls, sevin, eight, or bifenthrin are all labeled for use in the vegetable garden. Be sure to watch the PHI, pre-harvest interval, or amount of days to wait from application until harvest. For squash bugs make sure you are spraying thoroughly on the underside of the leaves where the eggs are laid to kill larvae just as they emerge. You can also squash the copper-colored, football shaped eggs as you find them on the underside of the leaves. Be sure to clean up the garden in the fall to eliminate the overwintering site.

5. This caller had 3 questions. First, when and how short can a spirea be pruned?

A. It is a spring blooming spirea, so it should be pruned within a few weeks after blooming has completed for the year. Up to 1/3 of the plant can be removed in one season. So if it is 3 feet tall, you can remove 1 foot of the growth. Be sure to prune back to a side branch. Continual shearing will leave heavy growth at the base of the plant with spindly growth on top. Spireas can be renewed with a rejuvenation pruning where it is cut back to 6-8 inches above the ground. This should be done in the fall and not every year. You will not see blooms the year following a rejuvenation pruning.

How do you prune lilacs? It is overgrown.

A. If the lilac is overgrown, it can be pruned through a rejuvenation pruning in the fall, like suggested with spireas. Otherwise, it should be pruned within a few weeks after blooming has been completed in the spring.

His final question was about tree black walnut. The tree was pruned at a random location mid-way through the branch. It has now died back further than where it was pruned. What is wrong with it?

A. Be sure to make a good pruning cut. Branches either need to be pruned back to the trunk, just outside of the branch collar, or to a side branch. The side branch needs to be at least 1/2 the size of the branch being removed.

6. A caller has poppies that she received from the Yukon. These poppies are blooming now and she wants to dead head so they continue to bloom, but she also wants to save the seed to start some new plants. Can she cut the flower heads off before they fully dry to save the seed?

A. The seed needs to be allowed to fully mature on the plant. So, unfortunately, you will have to choose between dead heading and allowing the seed to mature on the plant. If they are picked too soon, some may germinate, but the rate will be low.

7. An emailed question regarding the listeners garden which was hit by herbicide drift. Will the produce from this garden be safe to consume?

A. There is no way to know for sure when or if the produce will be safe to eat. It is better to throw it out and start over when in doubt.

8. This caller was curious about collecting seed from winter onions, or walking onions. She tried last year but they didn’t grow at her house after she took the above ground bulbs from her sisters plants. What does she need to do differently to get these onions to grow?

A. These also need to be allowed to fully mature on the plant, like the poppies. The stems with the above ground bulblets on them will dry up and fall over. When they are falling over the bulblets are mature and can be picked up and planted in new locations. If the bulblets were picked off the plant prior to this, they were not fully mature and wouldn’t develop into new plants.

9. A caller has oak trees that the branches are dying from the bottom up. What can be done?

A. These are likely pin oak trees and it is very common in pin oak trees. The lower branches could be dying due to lack of sunlight. It could also be due to a few diseases. If the branches are dead with no leaves, they should be removed to keep them from falling. If this continues, a sample could be submitted either by photo to me or a sample to the diagnostic lab at UNL, linked above.

10. This caller has tomato plants that were cut off at the ground level but the plant was left behind. What caused that? How can this be stopped?

A. This was likely due to cutworms. They can be managed by using sevin or diatomaceous earth around the base of the plant when they are planted. You can also wrap the base of the plant with aluminum foil to prevent feeding. This caller took the plants inside the next day and placed them in water and in soil to try to re-root them, it worked for some. Great idea, if caught early enough!

She also wondered if diatomaceous earth is effective for squash bugs?

A. It would not be as effective for squash bug adults. It can be used for squash bug nymphs.


11. A caller sprayed his evergreen trees with Tempo to treat for bagworms and it rained just a few hours later. Will he need to respray?

A. The label states that it is rainfast after 24 hours, it is likely that this application was mostly washed off. The label also states that it can be reapplied every 7-10 days, so it would be best to wait about 7 days before reapplying. It would still be within the timeframe for spraying bagworms at that time.

12. This caller has been able to hand-pick bagworms off of her small tree through the year. Does she also need to spray?

A. If you are able to continue to pick the bagworms off as you see any new bags form, you wouldn’t have to. If you see a large amount of small, black caterpillars or if a large quantity of bags form on the tree, you can spray.

13. How often can you spray Eight to control squash bugs?

A. Remember to always read and follow the label when using pesticides. It would likely be fine to spray every 10-14 days through the season, but one label I looked at said every 3 days if necessary. Just be sure to follow what your label states and also follow the PHI, pre-harvest interval, or amount of days to wait from application until harvest.

14. A caller has an oak with old scars where limbs were removed by previous home owners. One of the wounds is weeping. What is causing this weeping? What can be done about it?

A. This is likely due to a bacterial infection of the heartwood, called wet wood disease. Those pruning scars did not fully seal over and it has allowed the bacteria to enter the tree. It is minimal damage to the tree and won’t kill the tree. There is nothing to do to stop the weeping, but again it doesn’t really hurt the tree.

15. The final question of the day was from a caller who has cucumber plants with leaves that are drying up and dying. What is causing the browning which starts on the outside edge of the leaves? Can anything be sprayed on the plants to stop the damage?

A. This is likely either environmental stress or a slight fungal disease. The environmental stress could be due to the heat or drought stress if they aren’t receiving sufficient irrigation through this hot, windy weather. It could also be from a fungus, there are many that affect cucumbers. A fungicide, such as copper, could be used to reduce the spread. Without a picture, it is hard to determine for sure what is affecting these plants.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Yard & Garden: May 29, 2020

This is the Q&A for the Yard and Garden show for May 29, 2020. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 31, 2020. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: No guest host due to COVID-19 and social distancing

1. The first caller of the show has tomato plants that now is developing “skinny” leaves. What is wrong with them?

A. The leaves are skinny and deformed. This is likely from herbicide drift, it is hard to say for sure without seeing the plants, but it sounds most like herbicide drift. This has started to become a problem again this year due to the change in weather. As we warm up, we see more problems with 2,4-D and dicamba products that turn to a gas and move to non-target plants. Tomatoes are very sensitive to drift from 2,4-D or Dicamba products. They should grow out of the damage, however because we don’t know exactly what product hit these tomatoes there is no way to know for sure when the product will be out of the tomatoes. I can’t say when or if these tomato plants will be safe for consumption this year.

2. This caller has a very large hosta. When can it be divided?

A. Early spring is the best time to divide hostas, once they have emerged from the ground but before the heat of the summer. It might be a little late to divide the plants this year due to the hot weather expected next week. If they are divided now, be sure to keep them well watered.

3. When can oaks and maples be pruned?

A. The new pruning recommendations show that pruning is best if done in late spring, so late May to early June for Nebraska. Now would be a good time for most trees, however, oaks are susceptible to oak wilt if pruned during the summer months. It is best to wait until fall, September or October, to prune oak trees to avoid this disease. Maples, can have a heavy sap flow in the spring, they can be pruned now, but may leak sap, sometimes large quantities. They would be better to prune in the fall also.

4. A caller was going to use Grass-B-Gon on some weeds she recently hand-pulled to reduce the hand-pulling in the future. How long should the regrowth be before she applies the grass killing product to her landscape beds?

A. As long as you start to see some new, green regrowth, the product should work. According to the label, it should be applied anytime weeds are actively growing, which would be when you see them green up again around your landscape plants.

5. This caller is on her second round of planting tomatoes and they are turning yellow again. She planted the first in late April and then again recently. In the new planting one plant is starting to turn yellow. She is using straw mulch on most of the plants but is using grass mulch on the one plant that is turning yellow. What is wrong with her plants?

A. The first round of plants were planted too soon and we saw quite a bit of cold weather later in the season this year than many other years. She did cover the plants on the sides, but left the top exposed. Frost would have settled down onto the plants and killed them. The new plants are doing fine except the one plant that has grass clippings on it. The lawn has been treated with broadleaf weed control as well as crabgrass control this year. The labels will tell you not to use the clippings on the garden for the season or for a period of time. If that isn’t being followed and this is the one plant that is looking bad, I would assume that the grass clippings are the problem. Be sure to use clean grass clippings or use straw for all of the plants.

6. A caller pulled 3 mature barberry bushes with a pickup truck and then decided to replant them after all. What should be done to keep them alive? Should they be fertilized?

A. Pulling these plants out with a pickup truck and chains would have drastically damaged the cambium layer which can reduce the flow of water and other nutrients through the plant. They were also kept out of the ground for a week before being replanted. These plants could pull through if they are tough, but you will need to make sure they are kept moderately watered. Don’t overwater, but don’t allow the plants to dry out either. A slow trickle for about 10 minutes a couple of times per week will help to rebuild the roots. Do not fertilize them. Fertilizing a stressed plant can further stress the plant. Only time will tell if they can survive.

7. This caller has lilacs that are looking bad and didn’t bloom well. What can be done to help them? When can they be pruned?

A. Sounds like this lilac is in need of a rejuvenation pruning. This is where you cut the plant off about 6-8 inches above the ground level to rejuvenate the growth. It will reduce insect problems and push new, young growth to provide better blooming and have a healthier plant. This can be done in the fall for best results.

8. A caller had bagworms on her cedars last year. She also noticed a lot of praying mantis egg cases, she knows they are a good predator.  Are the praying mantis’ helping to control the bagworms?

A. Praying mantis’ are not a major predator of bagworms. They prefer feeding on aphids and others.

She also wondered about her forsythia that was injured by the late frost this year. It didn’t bloom this year and she had to cut back some of the branches. Will it bloom next year now or did this damage the blooms for next year as well?

A. The blossoms are set on the new growth that will form this summer. As long as they are pruned back within about 3 weeks after their bloom period, they will still bloom next year. This is why we prune forsythia just after they bloom rather than in the late winter. This forsythia should still bloom next year.

She had one final question, how can she control a clover-type weed growing profusely in her iris beds?

A. This will be difficult to do without harming the iris plants. She could spray with Roundup using a piece of cardboard as a barrier between the weeds and the iris plants or she could use the “glove of death”. This is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it.

9. What can be done to control elm saplings in a windbreak?

A. You can go through and cut off the trees and follow that up with a stump treatment using either 2,4-D or a glyphosate product, such as Roundup. The Roundup would be better this late into the year to avoid volatilization issues from the 2,4-D in the heat. Use the concentrate and just paint it on to the freshly cut stump for best control. Do NOT use Tordon, that will likely kill the spruce trees, and it is against label directions.

10. A caller planted grass in the spring. It is getting to about 2 inches tall now. When can he spray the weeds coming in with the grass?

A. You should wait until after 3 times mowing the new lawn before any herbicides should be applied to the grass to avoid injury. However, by that time, it will be too hot to use any 2,4-D products, which will turn into a gas and move to non-target plants and injure them in temperatures above 80-85 degrees. It would be better to just wait it out and spray in the fall to manage the weeds after the turf is more established. The fall is a better time to treat for perennial broadleaf weeds because it is when the plant is taking nutrients back into the root system and it will take more of the herbicide with it. Spray twice in the fall, once in mid-September and again in early to mid-October.

11. This caller has a hydrangea that didn’t look like it was going to live through the late frosts this spring. She did notice that it is finally coming up but it is only about 3 inches tall and is setting blossoms on. Should she remove those or let the plant bloom at such a small size?

A. It would be best to remove those blooms to allow the plant to grow a bit more before trying to bloom. All the energy in that plant would push into flower production, at such a small size, it would be best to allow the plant to build leaves and the root system to help it so it comes back next year.

12. A caller wants to know what to do to keep iris blooms from falling over?

A. Sometimes if the flower is too heavy it can fall over a bit. There are metal rings you can purchase to put in flower beds around plants that fall over to keep them upright, but nothing else will work for this. The flower is just too heavy for the stalk.

13. If branches on a tree or shrub are already dead can they be pruned off now?

A. Yes, dead branches should be removed as soon as they are noticed to prevent injury or damage from a falling branch.

14. The final call of the show asked if they should be fertilizing lilacs that were planted 3 years ago?

A. Fertlilizer doesn’t need to be used on plants that are growing just fine. Most trees and shrubs can get the nutrients they need to survive from our soils. The best thing is to do a soil test prior to adding any soil amendments, nutrients can build up to a too high level which can also damage the plant.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Yard & Garden: April 24, 2020

This is the Q&A for the Yard and Garden show for April 24, 2020. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 31, 2020. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: No guest host due to COVID-19 and social distancing

1. The first caller of the day had his yard sprayed for broadleaf weeds yesterday. How long should he wait before overseeding the lawn?

A. According to the label of Trimec, grass cannot be reseeded until 3-4 weeks after applications from the product. Any 2,4-D product would be similar. At this point, it would be best to wait until the fall to overseed the lawn, because that late in the spring would be hard to get the turf established. Be sure to tell your lawn company not to spray it in the fall until after the new grass has been mowed 3 times in the fall.

2. Can you start sweet potatoes from the sprouting sweet potatoes purchased from the grocery store?

A. You can, but they may not grow quite as well as desired. The varieties in the grocery store may not be as hardy as some of the varieties from the garden centers.

3. This caller is planting cucumbers, zucchini, pumpkins and other cucurbit plants. How far apart do they need to be planted to prevent cross-pollination?

A. The cross-pollination affects the produce in the following year, not the current growth period. The produce on the plants this year will be fine, but if they cross-pollinate, the fruits produced next year may not be true to the variety you are saving seed from. They also have to be in the same species to cross-pollinate, and cucumbers and zucchini are not.

4. A caller has rhubarb plants that are producing seed heads. Why is that happening so early and should anything be done about that?

A. The cold temperatures from last week are unusual and have “confused” the plants. This has pushed the plants to produce seed stalks. When rhubarb plants begin to produce seed stalks they push their energy into seed production and not into leaf and stalk production. To push that energy back into the stalk production we desire from rhubarb, cut the seed stalks off of the plant.

5. This caller has a rose garden that has chives coming up among the roses. What can be done to manage the chives and not harm the roses?

A. Among other plants it is best to use the “glove of death” which is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the leaves of the chives to kill it. This will likely take multiple applications over multiple years to completely rid the garden of the chives, but this is best to not harm the roses.

6. A caller is wondering what the best method is for transplanting 5 foot tall peach trees?

A. The best time for this would be in the dormant period, either in the fall or late winter months. Be sure to get as much of the rootball as possible.

7. This caller has planted the Hairy Balls plant and now grass is growing up among the plants. Can Grass-B-Gon be used in these plants to kill the grass and not harm the plants?

A. It should be fine, Hairy Balls plant is in the milkweed family which is not a grass. It would be best to avoid spraying directly on the foliage of the desired plant to ensure limited exposure.

8. This caller started lettuce, spinach, and some herbs before the snow. They have not come up yet. Will they be ok or should they be replanted?

A. Give the plants a little more time to see if they come up yet. If they hadn’t germinated yet, they should be ok, but the soil temperatures were too cold with the snow and freezing temperatures last week for them to germinate. If they don’t come up soon, you can try to reseed or move these crops to a fall garden because we are going to start getting too warm soon.

He also wanted to know if his strawberries will survive? He planted them as roots prior to the snow, and they had no real above-ground growth prior to the snow.

A. Those should be fine, because they hadn’t started to grow yet. The roots should have been protected enough to survive.

9. A caller has strawberries that are growing in a raised bed. The strawberries in the center of the bed seem to have died out. Can she move some new starts from the outside edge to the middle now? Also, what should they be fertilized with? She has some 11-15-11 can she use that?

A. Yes, it is ok to move established plants now to fill in the bed better. The fertilizer she has would be fine to use. Just be sure to follow the label instructions on applications.

10. When can a magnolia tree be pruned to allow a lawnmower underneath?

A. The timing for tree pruning has shifted a little recently due to new research. The International Society of Arboriculture has moved the time frame to correspond with the spring growth flush which would be May through early June for southeast Nebraska. This allows the tree to seal up the wound faster with less disease and insect issues.

11. This caller has snowball bush hydrangea plants that are spreading and growing into the lawn. Can he divide the plants to move the plants that are spreading into undesired areas to grow in better locations?

A. Yes, either do it now or in the fall. When you dig them up, they may be attached to the main plant, just prune that connection off to move them.

12. A caller has iris plants that had pushed new leaf growth and then were hit by the snow and the tips of the leaves are brown and discolored. What should be done with that?

A. The plants will be fine. It might be best to wait until a few more leaves appear that are not brown, then the entire leaf that is brown can be removed. Wait to get more new leaves to avoid removing all the sugar producing leaves to be removed now.

13. What are some good plants for pollinators? Where should these be purchased?

A. Good choices would include butterfly bush, butterfly milkweed, milkweed, goldenrod, coneflowers, bee balm, sunflowers, coreopsis, and many more. They can be purchased at local nurseries and garden centers. Pollinator seed mixes can be found at some seed supply companies, including Stock Seed Farms in Murdock, NE.

14. The final caller of the day planted pampass grass it started to green up, but now after the snow nothing seems to be alive. Will these plants be ok?

A. Give the plants a couple more weeks to see if they will regrow. The roots should still be fine and it is likely that they will regrow, but if nothing in a couple of weeks, there would still be time to replant these.

*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.

Do’s and Don’t of Late Winter Pruning

February and March have inconsistent weather patterns. It can make it hard to stay indoors on days in the late winter when the temperatures reach near or above the mid-50s. When we can go outside we feel we can do yard work, but don’t get too excited in your landscape too early in the year.

Pruning Trees

We have always pruned deciduous trees in the late winter, however new research shows the optimum time to prune is really in the late spring to early summer. We now recommend tree pruning in May to June. The reason for this change is that through research they have determined that this is the time when tree cells are most active during the season and it promotes the quickest sealing of the pruning wounds.

When we prune in the winter months, the pruning wound will sit open and exposed to disease and insect infestation until the wound can be sealed up. If you do the pruning during the most active time for the plant, the wound will seal up very quickly, greatly reducing the damage to the tree overall.

However, we may not always have a choice on the pruning time. If you are hiring an arborist to do the work, they may only be able to fit it into their schedule earlier in the season. Also, if you have damage from a storm, you would want to do corrective pruning as soon as possible. Also, remember that oaks are best pruned during the winter months to avoid potential infection from oak wilt. Oaks should be pruned in December, January, or February.

Pruning Shrubs

You also want to be careful pruning shrubs in the late winter. If it is a spring blooming shrub, the blooms are already present on the shrub for this spring. Pruning now could reduce the bloom or eliminate it all together, depending on how you prune. For a rule of thumb, if it is a spring blooming shrub, prune it within a few weeks after it blooms in the spring. If the shrub blooms in the summer, prune it in the late winter. So you can prune summer blooming shrubs this time of year. Examples of shrubs to prune in late February or March include spirea, potentilla, and smokebush. Examples of shrubs to wait to prune until after they have bloomed this spring include lilac, forsythia, weigela, mock orange, and viburnums.

Pruning Fruit Trees

Late February through March is a great time to prune fruit trees. Fruit trees need to be pruned to maintain good structure and air flow to allow for best production. They are best pruned during the dormant season, in late February through March. Peaches and apricots should be the last trees pruned in late spring, just before growth begins, to avoid winter injury. Peaches and apricots are less winter hardy and therefore more susceptible to damage from early pruning. Apples, plums, cherries, and pears can be pruned a little sooner than peaches and apricots, but still none should be done before January to avoid damage from winter injury.

Fruit trees are often neglected leading to overgrowth. It is important to remember that no tree or shrub should have more than 1/3 of the plant removed in one growing season. If it is a neglected fruit tree, it may take a few years to get the structure back to the desired shape.

The information for this article came from the HortUpdate from Nebraska Extension. Sign up online for this monthly newsletter for green industry professionals at hortupdate.unl.edu

Yard and Garden: June 14, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for June 14, 2019. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 2, 2019. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Dr. Paul Read, Professor of Viticulture, UNL

1. The first question of the show was what to do to get rid of borer bumble bees that are burrowing into the framing of a shed?

A. These are carpenter bees. Carpenter bees are a good pollinator insect. If they aren’t damaging the structure of a building, they can be left alone. However, if they are digging into framing for a shed or other building, filling the holes in with wood putty should work. Otherwise, you can spray a little sevin in the holes as well. You might also try putting up a Bee Hotel that may be more desirable to them than the structure of your building. View this article on Carpenter Bees for more information. View this NebGuide on Creating a Solitary Bee Hotel to learn how to build and place a bee hotel on your property.

He also wants to know what likes peas? His plants bloomed and then something ate the top third of the plant off. What would do that?

A. This could be deer, rabbits, or squirrels. These are all difficult wildlife to control. Fencing 2 feet high around them will keep rabbits out, the fencing needs to be 4 feet tall to keep deer out. Squirrels can climb the fence, so they are more difficult to manage in the garden. For more information on controlling squirrel damage, view this NebGuide on squirrels.

2. A caller has 4 peach trees, 2 have been producing fruit while 2 have not. Are there male and female peach trees? When will the other 2 produce?

A. Peaches are not male/female trees, they have perfect flowers and are self-pollinating. If they aren’t flowering they are not mature yet. Once they begin flowering they will produce fruit.

3. Are cedars asexual trees?

A. Cedars are dioecious, meaning that they have male and female flowers on separate trees. You can see the difference in the trees in the spring when one tree looks brown while the next tree is green.

4. This caller has roses with holes in the leaves. What is causing this?

A. This is due to rose slugs, which is the immature form of a sawfly. Rose slugs are not terribly damaging. They can cause some defoliation early in the summer months but only for a few weeks and the damage is minimal. Spraying for rose slugs could harm pollinators while the plants are blooming.

Roseslug Collage
The picture on the left shows the rose slug on the underside of the leaf. The picture on the right shows the damage from rose slugs.

5. A caller just planted some gooseberry bushes. What care should be given to them now? Do they need to be cut back annually?

A. Gooseberries require minimal care. Cut out any damaged canes each year, but otherwise, leave them alone.

6. This caller was wondering about a plant called ‘Thuja’. Will it grow ok here?

A. Yes, Thuja is the genus for arborvitae. Arborvitae will grow fine here, but it can be problematic in cold snap winter conditions. They get a lot of winterkill. A local nursery will have varieties that are better suited to our environment than those found in a mail-order catalog.

7. A caller has an American Elm that is dying. Last summer it lost all of it’s leaves early, now the tree looks dead on portions. What is wrong with it?

A. This could be from Dutch Elm Disease. There are still elms in the area that have made it through Dutch Elm Disease, but the disease will catch up with them and kill them. There is no cure or anything you can do to save a tree from Dutch Elm Disease. Remove the tree.

8. This caller has a 14 year old maple tree with branches hanging on the ground making it difficult to mow around. Can those branches be cut back now?

A. Yes, it would be fine to prune it back now. This time of year is beneficial because the wound will seal up quickly with the active growth of the tree. Be sure to make a good pruning cut. For tips on how to make a good pruning cut, view this article from Sarah Browning on Pruning Deciduous Trees.

9. A caller has a rose bush that bloomed good for a while, now it has started to die. The leaves and flowers are wilting. She waters 1 inch per day. What is wrong with them?

A. Watering the plants 1 inch of water a day would be excessive. It would be better to reduce that down to 1 inch of water per day, especially with all of the rain we have been seeing lately. Be sure to add a 2-3 inch layer of mulch to the plants. Don’t fertilize them right now, fertilizing a stressed plant can further stress it.

10. This caller is looking for a source for corn gluten meal for weed control.

A. Try looking at local nurseries like Campbell’s or Earl May. Be careful with corn gluten meal, if too much is applied it can kill desirable plants.

11. A caller is using rural water now instead of rural water that they had used before moving. The rural water smells like bleach, will it hurt the plants? Also, she adds manure every year to it, is the soil causing problems to the plants?

A. The water shouldn’t affect the plants. If there is a concern, you can get the water tested to ensure that it is safe for consumption. Also, be careful just adding manure every year. It would be a good idea to get the soil tested prior to just adding more nutrients. Nutrient levels that are a little high can be just as detrimental as low nutrient levels.

12. The last caller of the day started his tomato plants in the upside down planter. Should he put a cage around them?

A. That wouldn’t be necessary because the plants are going to naturally grow upward. Cages are used on the ground to keep our plants from falling over, these would be held up by the planter.

Tree Selection and Pruning

2014-06-12 16.10.39

Arbor Day is Friday, April 28th, 2017. Arbor Day is always an exciting day for me because I really appreciate trees and understand the real potential that can come from planting a tree. With Pine Wilt and the concerns of Emerald Ash Borer creeping closer it seems there is always a need to plant a tree, if not for you, then for future generations.

There are a lot of good trees to plant when you do plant a tree. The most important thing to remember when planting trees, is Diversity. When you go to purchase your tree, look around your yard and even your neighborhood. Try to avoid planting multiple trees of the same species, genus, or family of plants in the neighborhood and in your own landscape. You may enjoy Maples, but you want to make sure you plant other types of trees in your yard besides just maples to help avoid an issue that may arise should another pest come through like what we saw with Dutch Elm Disease or Chestnut Blight or now Emerald Ash Borer.

2014-10-06 15.27.18

Each year, ReTree Nebraska comes out with a new diverse list of trees that grow well in Nebraska and are often under-utilized. That list includes Baldcypress, Catalpa, Kentucky Coffeetree, Elm Hybrids, Hackberry, American Linden, Sugar Maple, Chinkapin Oak, Bur Oak, English Oak, Sycamore, Shantung Maple, Miyabe Maple, Gample Oak, Tree Lilac, Concolor Fir, Black Hills Spruce, and Ponderosa Pine. In 2017, ReTree Nebraska added Turkish Filbert including other nut trees such as Hickory, Chestnut, Pecan, Buckeye, and Walnut to the list of good trees to plant in Nebraska. There are a lot of other great trees to use in your landscape, this is just a short list.

Turkish Filbert is a unique, under-utilized tree in Nebraska. It grows up to 40-50 feet tall and 30-50 feet wide. It has large, bright green leaves that turn yellow in the fall. This tree has catkin flowers, like a cottonwood.  It has edible nuts that are produced in a cluster of 3-6 and have a spiny husk that covers the nuts. Often squirrels eat the nuts, but they can be roasted and eaten by humans. This tree is most commonly used as a shade tree or a specimen tree in a landscape.

Another thing to think about with our young trees, is pruning. Eric Berg, a community forester from the Nebraska Forest Service wrote a great article on pruning young trees. We need to start pruning our trees when they are young to minimize tree wounding and cause the trees to grow stronger, mature growth. A tree planted in a landscape setting, rather than being planted in a forested area, will grow out more than up and not develop a strong central leader. Often our trees develop multiple leaders that lead to weak growth that can easily be broken in storms. We saw the damage from weak branch attachments and poor growth in our ice storm this past winter.

pruning tools-K. Todd
Photo courtesy of Kim Todd, UNL Department of Agronomy and Horticulture

We can prune a tree when it is young to help prevent some damage in future storms. If you would like to learn more about pruning young trees, Graham Herbst, from the Nebraska Forest Service, will be in Beatrice to teach us about pruning young trees on Monday, June 19th from 6-8 pm starting at the Gage County Extension Office. He will cover how to set pruning objectives, determining a pruning cycle and dose, strategies for specific trees, and how to execute your plan with proper cuts. There will also be a hands-on pruning demonstration at the end of the classroom portion. If you are interested in this program, please call the Gage County Extension Office at 402-223-1384 to sign up.

Yard and Garden: April 14, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for April 14, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: George Pinkerton, Director of Landscape Maintenance at Downtown Lincoln

1. The first question came from a caller wondering what the timing is for crabgrass preventer?

A: Typically we go with mid-to late April for application of crabgrass preventer. Crabgrass germinates when soil temperatures reach 55-60 degrees Fahrenheit. In most of the Southeast Nebraska area, we have just recently hit that. Anytime in the next couple of weeks would be fine to apply your crabgrass preventer. It might be best for control to apply a split application this year. For a split application, apply half of the recommended rate now and the other half of the recommended rate 8-10 weeks later. The split application will give you a longer season of control for crabgrass and other annual grassy weeds.

2. A caller was wondering about their gladiolus bulbs. They have had problems with thrips insects in the past and they had heard they should soak their bulbs in lysol to control them. Is this a good method of control or is there something better?

A: As it turns out, you can soak the corms in a solution of lysol water prior to storage of the corms over the winter months, according to the University of Minnesota Extension. You can also dust the corms with a sevin dust prior to storage in the late fall, store them with mothballs, or store them at colder temperatures such as 35-40 degrees F as well. If you are looking for control at this time, it would be best to spray the plants as you see the streaking damage beginning from the thrips feeding in the spring and summer months. You can use any general insecticide for this.

3. This caller has a sugar maple that was hit with hail 5 years ago and now has a great deal of damage to the trunk of the tree. They have sprayed the trunk with a sealant and used a wrap. Will the tree survive or should it be removed now?

A: At this point, I would observe the tree to watch for signs of death occurring through the tree. The damage that is there cannot be fixed now that it has occurred. If you don’t like the look of the damage you can remove and replace the tree or you can wait until it starts to dieback. It is hard to say how long the tree will live now that the damage has occurred.

2012-05-25 12.04.38
Bare lawn in need of overseeding.

4. A caller wants to reseed. What seed should he use?

A: For a new seeding, use a turf-type tall fescue or a Kentucky bluegrass. Use either 100% of either of these types or use a 50% mix of the two. For more information, see this article from the UNL Turfgrass Department on Choosing Grass Seed.

5. A caller has a section in fairly high shade that died out last year. Why and can it be reseeded?

A: In locations of very high shade turf doesn’t always do well. The caller said this had been growing there for 25 years so it could have been a fluke that the lawn died out last year. You can reseed now with regular turf or you can use a shady groundcover such as a carex species.

6. When is the time to transplant coreopsis to a location with more sun?

A: Now would be a great time. Mid April through mid-late May is a great time to transplant perennials.

7. This caller has some large pin oaks that need to be pruned to make it easier to mow underneath the tree. Is it too late now to do that?

A: Yes, it would be better to wait until late fall to prune the oaks now. Oak trees are susceptible to oak wilt which is spread by a beetle in the summer months. It is best to avoid pruning them at this time of the year to reduce the incidence of disease.

8. What kind of tree would be a good choice for shade production in a backyard?

A: Any of the oak species, shagbark hickory, sycamore, Linden, Kentucky coffeetree, Black locust, thornless honeylocust, hackberry, and many others.

Curly Dock, Steve Dewey, Utah State Univ, Bugwood
Photo of Curly Dock from Steve Dewey, Utah State University, Bugwood.org

9. A caller wants to know what to do for management of curly dock?

A: 2,4-D or Trimec can be used this time of year or use a mixture of 2,4-D and Roundup.

10. What do you do for thistles growing throughout a yard?

A: 2,4-D or Trimec, but these products are best used in the late fall or before flowering. Thistles are a biennial so if you can dig up the plants as a rosette in the first year of growth they will die.

11. This caller has cherry trees that are suckering. Can one of the suckers be dug up now to start another plant?

A: Yes, it can be done now, but fall would be a better time of the year for this. If it needs to be done, it can be done now. However, depending on the type of sucker growth, the new plants may not be the same as the original plant or they may have weak growth.

12. An email from a listener asked what is wrong with his pin oak that has leaves that are curled up like they were hit with a spray? He wondered if they were too close to the windbreak that is 20 feet away? Is there a certain distance you want to stay away from your windbreak when planting other trees?

A: You do need to give your trees space to grow, but pin oaks are often planted as a third, interior row to a windbreak. The spacing between rows would be 15-20 feet, so the proximity to the windbreak would not be a problem in this instance. Most of the time if a tree is lightly hit with spray drift from a pesticide, it will not show in the tree every year unless it is hit every year. In this case, I would ask for a picture or sample to help with further diagnosis.

13. When is the best time to transplant peonies? Why isn’t the rhubarb up yet?

A: Fall is the best time to transplant peonies. If necessary for construction or moving purposes, it can be done yet this spring. Plant them at the same depth at their new location. As for the rhubarb, give it a few more weeks to see if it comes up before giving up on it. If it is in a location that is more exposed to cold winds the soil may have not warmed up enough yet this spring.

14. This caller wants to know what type of fertilizer to use in a garden?

A: A low grade, balanced fertilizer is best for a garden, like a 10-10-10 or 12-12-12 with slow release fertilizer is best.

15. The final caller of the day wanted to know if now was the time to fertilize pecans?

A: Many of the trees in our environment have sufficient nutrients for growth and so fertilization on these pecan trees may not be necessary. If you are concerned with the growth of the tree, take a soil test to see where the fertility levels are. If it is growing fine, don’t fertilize it because our trees and other plants can be over-fertilized which can cause injury or even death.

Yard and Garden: March 31, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for March 31, 2017. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through July 28, 2017. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Natalia Bjorklund, Nebraska Extension Educator in Dodge County

1. The first question was when can we begin applying crabgrass preventer and fertilizer to our lawns this spring?

A. These are both best applied in late April to early May. Crabgrass will not germinate until the soil temperatures are consistently at 55-60 degrees Fahrenheit.

2. A caller wanted to know if he should mulch his asparagus and if he can use ash wood mulch around his asparagus?

A. Yes, mulch is one of the best ways to manage weeds in an asparagus patch. Ash wood chips would be fine. You do want to avoid Walnut wood chips because walnuts produce juglone which is a chemical produced by the tree to act as a weed control for nearby plants. This helps walnut trees with competition in the wild.

3. This caller has a goldenrod that has grown too large and messy for the area where it is planted. How can it be killed and what Goldenrod would be a better choice for a less messy plant?

A. 2,4-D or simple hand removal should kill the plant. When purchasing a Goldenrod plant in the future, any of the varieties would be better than the straight species. Fireworks is a nice, open goldenrod. Wichita Mountains and Baby Blue would be good choices as well.

4. Is it too early to transplant hostas? When should you cut back warm season grasses?

A. Wait a couple of weeks to transplant the hostas until the soil has warmed up a little more. You can cut back the ornamental grasses anytime now. It is better to get the old growth cut off before growth resumes so you don’t cut off the new growth. For ease of cleanup with the ornamental grasses, wrap string or twine around the plant before cutting off the old materials so it stays together when taking to the compost pile.

5. A caller wanted to know how and when to prune roses?

A. Wait until a little later into April to start pruning them. It depends on the type of rose to know how to prune them. This sounds like a climbing rose which can be pruned back about 1/2 to reduce the size. Wait until they start greening up to know which areas of the canes have died back, the dieback should be removed as well. If the canes are long and lean over mowing areas or other things, they can be tied up to a trellis.

6. This caller wanted to know how to get rid of cockleburs?

A. While talking with the caller, it came up that the plant had very small yellow flowers on it and there were spines over the plant except right at the soil surface. This plant is in fact buffalobur, not cocklebur. These are easily pulled up if you pull where there are no spines. A 2,4-D product could also be used if there was a large amount of them in the lawn.

buffalobur, Howard F Schwartz, Colorado State Univ, Bugwood
Buffalobur plant from Howard F. Schwartz, Colorado State University, Bugwood.org

7. A caller wanted to know if they should water in their crabgrass control?

A. The label will explain to you how a product should be applied for best efficacy. Always read and follow the label instructions to apply correctly. For many of the crabgrass preventers, they would need to be watered in, but again, check the label to be sure.

8. When should asparagus be fertilized?

A. Apply a general fertilizer or a composted manure to the bed after the last harvest or sometime in the fall.

9. This caller has mulberries growing in the windbreak. After they are cut down, what kind of stump treatment should be done to keep them from regrowing?

A. 2,4-D concentrate should be used as a stump treatment. This will take multiple applications and will be more effective if done in the fall. Each time the 2,4-D is reapplied it should be applied into newly drilled holes or to a freshly cut area of the stump.

10. A caller has cedars growing in their landscape. Under the cedars there is bare ground. What can they plant in that area to avoid weeds coming in?

A. The cedars are going to keep that area quite dark and the cedars will take the majority of the water in the soil so mulch would be a good alternative. If plants are desired, use a shade tolerant groundcover such as wintercreeper or vinca vine or perennial plants such as bleeding hearts, hostas, coral bells, jacob’s ladder, and others.

11. This caller has tiny cedar trees coming up throughout the lawn. How can they be controlled?

A. Cut them off at ground level. If a cedar is cut below any lateral growth it will not regrow. Mowing over them wouldn’t be low enough.

3-step pruning cut
Proper pruning cut, University of Missouri Extension

12. When is the best time to prune a maple tree that had a branch break in a storm?

A. As soon as the storm has passed and it is safe to do so, you should remove a branch that broke in the storm. If the damage occurred in a winter storm, let the ice and snow melt off first. Then, hire a certified arborist to come out and make a good pruning cut so that the tree can seal off the wound quickly and fully.

13. A caller has a hibiscus tree that is turning yellow and many of those yellow leaves are falling off the tree. It was moved indoors during the winter months in an area of the house with low sunlight. What is wrong with it and will it survive?

A. Hibiscus plants would need more sunlight than what it has received through the winter. It should be fine once it gets more sunlight. As the days get warmer, you can move it outdoors for more intense sunlight. It should be fine once it gets moved to better growing conditions.

14. This caller has a weeping willow tree that they would like to prune up a little. When can they prune it?

A. The weeping branches shouldn’t be pruned up too much or they could lose their weeping habit. Willows tend to have a heavy sap flow in the spring if they are pruned then, so it would be best to wait until later fall to prune a willow.

15. This caller has grasses that are coming up among the gravel paths around his daylily patch. What can he use to prevent those plants from coming up?

A. Preen is a great way to stop the germination of annual weeds, such as many of our weedy grass species. If they come up before the preen gets put down or if they grow as a perennial weed, you can use a post-emergent herbicide. If it is a grass that is growing out of place among daylilies, you can use Grass-B-Gon or a similar product to kill grasses.

henbit, steve dewey, Utah State Univ, Bugwood
Photo of henbit is from Steve Dewey, Utah State University, Bugwood.org

16. What can be done to manage henbit?

A. At this time of the year, there is nothing very effective at controlling henbit. Henbit is a winter annual plant, meaning that it germinates in the fall and flowers and produces seed in the spring. It dies with the summer heat. As we are now seeing the purple flowers from henbit, there is no need to control what you are seeing. The seed is already present in the lawn for next year and what you would be spraying will die soon. You can hand pull it now and spray with a 2,4-D product late in the fall.

17. This caller has moon flowers that had a lot of hornworms on them last summer. What can be done this year to reduce the number of hornworms?

A. Just because there were hornworms there last year doesn’t necessarily mean you will have a lot this year. Hornworms are sporadic pests. They are easily controlled by hand removal. You can also use sevin or eight or any other general insecticide. Use Bt to protect other pollinators as Bt is only harmful to insects in the order Lepidoptera which includes butterflies and moths.

18. What do you do for bindweed in a vegetable garden?

A. If you haven’t planted yet this spring, you can roundup the plants before you prepare the soil for the summer vegetables. The plants will probably still be a problem later in the year as this is a difficult pest to control. When it comes back in the summer, you can carefully use roundup through the growing season. You can paint the glyphosate product onto the leaves of the bindweed avoiding spraying the desired plants.