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 and Garden: July 12, 2019

Yard & Garden blog, 2019

This is the Q&A for the Yard and Garden show for July 12, 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: Sarah Browning, Extension Educator in Lancaster County

1. The first question of the show was about ivy growing on a garage. The caller had Japanese beetles earlier this year and sprayed with sevin. Now he is seeing a lot of flying insects, one looks like a lightning bug. What type of insect would this be and will they cause damage to his ivy?

A. They could be lightning bugs which will not harm your plants. Japanese beetles will come back, it would be best to keep spraying to ensure they stay away. You can use the sevin every 10-14 days or you can use a product containing Azadirachtin which has some repellent properties so it will help to keep the Japanese Beetles away longer.

2. A caller has a newly planted maple tree that has brown spots on the leaves. It looks like something is eating it but she can’t find any bugs. The spots look like brown strips with yellow around it. What is causing that?

A. This could be the tree drying up and getting heat stress. This tree was just planted this year so it isn’t established well and will dry out faster in this heat. She has been watering by hand and that isn’t getting the tree enough water. It would be better if she watered with a small sprinkler for about 45 minutes once a week.

3. This caller has a 40-year-old Ponderosa Pine that had diplodia tip blight that got so bad she removed the tree. There is a blue spruce nearby, would that tree be getting the tip blight as well? The spruce has tips of the branches that are bent over and the needles are all bunched together. What would cause that?

A. Diplodia tip blight will not affect spruces. It is a problem for pines, mostly Austrian and Ponderosa. This is not what is affecting the spruce. The damage on the spruce sounds like sirococcus shoot blight. It is past the treatment time for this disease, but it won’t kill your tree in one season. In the spring spruces can be sprayed with chlorothalonil when the shoots are 1/2-2 inches in length and repeated every 3-4 weeks if frequent rains occur.

Blossom end rot on tomato
Blossom end rot on a tomato

4. What can be done for blossom end rot in tomatoes?

A.  Blossom end rot is when the end of your vegetable that is away from the plant rots and turns black. It occurs on the end of the vegetable that had the flower, hence the name blossom end rot. The cause of this disease is a calcium deficiency, but calcium is in the soil in sufficient quantity, uneven watering will reduce the ability of the plant to access this calcium. Calcium has to be dissolved in water for the plant to be able to obtain it from the soil. Adding calcium to your garden is not effective for managing this problem. Not all of your produce should be affected by this problem, they tend to grow out of these conditions later in the summer, so there is no need to treat your garden for blossom end rot. Maintain moisture and mulch to help with this disorder.

5. A caller wants to know what to plant for a fall garden and when it should be planted.

A. Fall gardens can be very beneficial and work better than spring gardens due to the cooler temperatures and higher amounts of moisture in the fall. Start transplants indoors now for things like Brussels sprouts, broccoli, cabbage, and cauliflower. The average first frost date for most of Southeast Nebraska is October 6-16, this comes from data from the High Plains Regional Climate Center. You can use the first frost date to figure out when to plant fall crops. Use the first frost date as a starting point, count backward the number of days to harvest listed on the packet of seeds and add a 10 day fall factor because the plants will mature slower due to the cooler weather. Plants or seeds should be planted in late July to early August. You can also plant your second crop of warm season vegetables now if you haven’t yet to get a longer harvest period and possibly avoid problems with insects and diseases during their peak time.

6. This caller has a rose bush with something eating the leaves off it. What would cause this and how can it be controlled?

A. This could be from a couple of different issues. Japanese beetles will feed on the leaves of roses and cause the leaf to look like lace with little leaf left besides the veins. Rose slugs can do some damage to roses but it looks worse than it is and the feeding should be nearing completion for the year. If you aren’t seeing the insects, it could be rose chafers that feed at night. It could also be from a disease such as black spot. Look for a product that contains an insecticide and fungicide to help with any of these problems. A liquid would be better than a dust.

7. A caller has brown spots in his lawn. What is the problem and how can he fix it?

A. This could be due to either brown spot or dollar spot. These two diseases are quite common this year due to the wet spring and early summer conditions we faced. In a home lawn it isn’t usually necessary to use a fungicides because the fungi don’t kill the lawn and they are sporadic from year to year. It will fade soon and the grass will green back up. These diseases don’t affect the crown of the grass plant so it will easily grow out of it after a few mowings. Through discussion, we learned that his underground sprinkler system waters the lawn from 1am-6am. It was suggested that he do an irrigation audit and move the time for watering forward to 4am-10am. Watering overnight keeps the lawn wet in the cooler, dark environment which is great for disease development.

8. The final caller of the show have sugar maples that leafed out well this year but now the leaves are turning brown and dropping off the tree. What is causing that?

A. This could be from anthracnose, a fungal disease of the tree. It can infect the leaves and cause them to fall from the tree. It could also be from not watering enough now that the rains have reduced or from scorch. Be sure to water the tree and look for damage on the trunk or girdling roots. Look for borer holes as well and treat with imidacloprid if holes are present. It is most likely from an environmental condition, which we cannot change. The tree should be fine.

Yard and Garden: June 15, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for June 15, 2018. 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 3, 2018. 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: Jim Kalisch, Insect Diagnostician for UNL Extension

1.The first caller of the show wants to know how to attract more fireflies to his yard?

A. Fireflies like moist environments. So a location of higher shade that is kept moist with dense plantings will attract them to your landscape. Also, just keeping the lawn watered will help.

lonestar tick, lifestages, J. Kalisch
This photo from Jim Kalisch, UNL Entomology, shows the lifestages of the Lone star tick

2. This year has high populations of ticks found in nature. Many ticks around this area have been identified by Jim Kalisch as being the Lonestar tick. Is this species of tick increasing in population in Nebraska?

A. Lonestar tick nymphs are being found often now. They have been found in the southeast portion of Nebraska. The range for this tick has spread north over the past decade or 2 to include the southeast corner of Nebraska. Prior to this, the Lonestar tick was found further south of Nebraska. This tick is significant for health reasons because it spreads many diseases including Southern Tick Associated Rash Illness (STARI), rabbit fever and erlichiosis. It also can causes a food allergy to red meat. Because of this, it is always good to remember to use insect repellent sprays and check yourself for ticks when coming inside from outdoor activities.

3. A caller has a blue spruce that was planted from a container last spring at 3.5 feet tall. Now it is turning brown on top and the branches are getting a shepherd’s crook at the end of the branches. What is causing this and can the tree be saved?

A. This is likely a fungal disease called sirococcus shoot blight. The best time to spray the trees is in May with additional sprays every 3-4 weeks as rain occurs.  It is a little late for the spraying of this tree, but it would still be beneficial to spray the tree to reduce the spread. Using a liquid copper fungicide would be best. Next spring, spray the trees when the shoots are 1/2 to 2 inches in length.

Squash bug-NH-pic monkey4. An email question came through asking how to get rid of pumpkin bugs in the garden this year, he faces them every year?

A. From his description, these are likely squash bugs. They are common pests in pumpkins, as well as in cucumbers, squash, zucchini, and melons. If these bugs are in pumpkins that are for ornamental use only, not for consumption, a systemic insecticide called acetamiprid can be used. Be careful if using in a garden with other edible garden plants, read the label for the PHI to tell you how long to wait from when you apply this product until you can harvest again. If these plants will be used for consumption, eight or bifenthrin would work for less PHI. Still pay attention to the PHI for harvest times.

5. This caller has oriental poppies in her garden that have faded now. They are planted in an area that is becoming overtaken by weeds. She would like to plant mums around the poppies to get a longer season of interest. How can she work the soil to plant the mums and kill the weeds, while not harming the poppies.

A. Tilling through the garden space may not be the best answer. If you till through weeds, it can sometimes cause more of a problem. Many weeds will propagate vegetatively, so new plants will form from each of the cut pieces of the main plants. Also, it would be difficult to till around poppies safely. I would recommend carefully using glyphosate on the weeds for better control, do not use any 2,4-D or Dicamba products this time of year due to problems with these chemicals turning into gas and moving to non-target plants. Spot spraying the weeds or painting the chemical on the leaves would get more of a kill for the weeds and the glyphosate product will not turn into a gas and it deactivates as it hits the soil. Finally, just go in and just dig holes where the new mums will be planted.

6. A caller wants to know when the best time is to move tiger eye sumac?

A. Fall would be fine to move this sumac, such as in September.

This caller also has a 5-year-old peach tree that has borers. How can the borers be controlled?

A. For borer control, it is best to treat the base of the tree and the branch junctions with bifenthrin. This chemical will have to be reapplied a few times through the growing season to help with the lesser peach tree borer and the peach tree borer which emerge at different times of the year. Applications should be made in June and again in July and August for best control.

7. This caller has a 2-year-old black raspberry. The new growth is curling and turning black, it seems to be moving from the tip of the leaf inward. What would cause this?

A. This could be from a scorch issue. Make sure that the plants are getting enough water, but check before just watering more. Often when we get scorch we automatically go to overwatering which can also be quite detrimental to the plant. For more information on scorch and how to deal with it, visit the Gro Big Red Blog Post on Scorch from Kathleen Cue.

8. A caller emailed pictures of his fir trees that are having some issues. One, was planted about 6 years ago and the bottom few branches have turned brown. He watered through the winter but has not yet this spring. The other fir was replanted about 4 years ago and the top is green, but the bottom half is sparse. What can be done for these trees?

A. The bottom branches of this tree could be just dying from shade or from a needle drop issue. That branch or 2 can be removed and the tree should be fine. It would be best to water this tree. Put the sprinkler in the root zone of this tree weekly for an hour or so to help it. As for the smaller tree, it is not going to make it. The lower portion is quite bare and it will be very difficult for the tree to come back from that.

9. What do you do about sandburs in a lawn?

A. Crabgrass preemergent herbicides should be used earlier in the season to control sandburs before they grow. Sandburs are a summer annual weed just like crabgrass. For post-emergent control, quinclorac products will work best. If it is in a driveway or other non-plant area, roundup 365 might be fairly effective.

10. A caller has a birch tree that needs a large branch removed, when is the best time for this? They also have a pear tree that needs some pruning, when is the time to do this? And when can they prune a mock orange bush?

A. New research is showing the timing for pruning has changed from what was previously recommended. We now recommend pruning in the late spring to early summer, so that would be right now for both the birch and the pear tree. It is better to wait until a little later in the spring to prune birch trees to avoid problems with heavy sap flow. The concern with this is that it was stated that a large limb needed to be removed, which can be quite harmful to the tree. Don’t remove a limb that is more than 1/2 the diameter of the trunk and do not remove more than 1/4 of the tree in one growing season. Removing a large limb leaves a large wound that the tree is not able to seal up. If the wound doesn’t get sealed, then decay can begin to move through the tree which can lead to the death of the tree in many years. In addition, removing more than 1/4 of the canopy in one season will remove a great deal of the photosynthetic area from the tree, which can harm the growth and development of the tree. The mock orange bush should be pruned within a few weeks after blooming for the year because it is a spring blooming shrub.

11. The last caller of the day wanted to know about pruning tomatoes and how to do it?

A. Tomatoes can be pruned if desired, but it is not necessary. If desired, only prune on indeterminate tomatoes, avoid pruning determinate tomatoes. Determinate tomatoes already will only grow to a certain size and produce a certain amount of tomatoes so they do not need to be pruned. Pruning tomatoes can decrease the amount of tomatoes produced and increase the size of the tomatoes and it can help increase air flow to reduce diseases. It will also help keep your tomatoes off the ground. When the plants are young, remove some of the branches. In some locations, 2 or more leaves will start to develop from one node, remove all but one. For more information on pruning tomatoes, here is a guide from Minnesota Extension.