Yard and Garden: April 7, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for April 7, 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 Hosts: Jonathan Larson, Extension Entomologist from Douglas-Sarpy Counties & Jody Green, Extension Entomologist from Lancaster County

1. The first question was to see if we could guess the caller’s favorite insect that was described as a moth with large, light green wings and feathery antennae?

A. This is a luna moth

2. A caller has moles in the yard and wants to know how to manage them?

A. A harpoon type of trap can be used, but should be prepped ahead of installation. This trap tends to work best if you stomp on a run to determine if it is an active run.  If it gets pushed back up, it is an active run. Stomp on this area a couple of more times and then set the trap to ensure the mole moves through the area. For more information on moles, click here for a publication from UNL on moles.

3. This caller wants to know how to get rid of creeping charlie in a lawn?

A. Triclopyr or a 2,4-D product can be used in the fall. For best control, use the product twice in the fall 2-3 weeks apart. September 30th and October 15th would be good dates for application. This is a tough weed to control, so it will take multiple years of multiple applications. A spring application of either of these products can be used as well to knock the weeds back for this year.

4. When can you transplant daylilies? Can they be planted into an area on the east side of the house with rock mulch?

A. Wait a couple of weeks until mid-late April to transplant them when the temperatures have warmed up more. Also, as long as the area is receiving at least 6 hours of sunlight daylilies will grow fine. This is a tough plant that will grow well in most conditions.

5. A caller has strawberries that had botrytis last year. When should they be sprayed to prevent the disease this year?

A. Apply from 5-10% bloom until flowers have finished blooming. For more information see the Midwest Small Fruit and Grape Spray Guide from Midwest Universities including UNL.

6. This caller has a pear tree that last year had orange spots on the leaves later in the season. What is this and how can it be controlled?

A. This is due to a rust disease, Cedar-Hawthorn Rust. It is more common in years following a wet spring. The timing for management is in the spring, May and June. See this NebGuide on Cedar-apple rust and related rusts of apples and ornamentals.

7. A caller has started corn, watermelons, and cantaloupe indoors from seed. The seedlings are getting quite large. Can they be transplanted outdoors now?

A. Unfortunately it is still too cold to plant these crops outdoors. These are warm season crops that should not be planted until early May after the frost-free date. These crops could be direct seeded at that time or transplanted but they tend to not do well as a transplant.

8. A caller has 2-year-old rhubarb plants that have come up and have thin, limp stalks. What is wrong with the rhubarb?

A. This could be due to crown rot. Rhubarb is very sensitive to high moisture soils and will often develop a crown rot in these situations. Those plants that have limp stalks should be removed and you can replant in a new location where it has more well-drained soil.

Bagworm4

Bagworm

9. When and what should you spray for bagworms?

A. May-June is the time frame for treating bagworms. It is best to spray them when the new bags are 1/2-1 inches long. Longer than that and they won’t catch as much of the pesticide to die as well. For spray choices, any general insecticide will work, but using Bt would be the least damaging to other insects because Bt only affects insects in the Order of Lepidoptera which includes butterflies, moths, and skippers.

10. A caller has Asparagus that has a green moss-like structure growing on top of the ground around it. What is it and what can they do for it?

A. A picture would be helpful in identifying this pest. If it is actually a moss, they may look into the water in the area because it is likely that it is too wet. If it is a weed, pull or hoe the weed and then add a layer of mulch to prevent further weeds from coming in.

11. This caller wanted to know what to do to grow bigger onions and if they should put Epsom salt on their tomatoes to help them grow more?

A. These onions are growing 3 inches apart, they should be spaced out more for larger sized onions. Place plants or sets 1-6″ apart in the rows, and 12-24″ between rows. For bulb production, plant onions in early spring. The number of leaves that form prior to bulbing determine the ultimate onion size. Since bulbing in each cultivar is triggered by a specific daylength, early planting is the most effective method of increasing bulb size, by allowing more time for leaves to form. If the onions do not grow well before bulb induction, the final bulb size may be smaller than desired. Avoid sets more than ¾ inch in diameter because they are likely to produce seed stalks.

As for the Epsom salt on tomatoes, no you should not apply this to your soil when you plant tomatoes. Our soils have a sufficient amount of magnesium and sulfate, which are the 2 ingredients in Epsom salt, so there is no need to apply more. If you need fertilizer, use a general fertilizer from the nursery or garden center.

12. A caller has a Japanese maple that was injured last May when the leaves curled up and fell off. The leaves never regrew through the summer last year. Will it come out of it?

 A: If it happened that early in the year last year and didn’t put on new leaves, it may be dead. Give it time this spring to green up. You can check if the tree is still alive by scraping the bark on a branch, if there is green underneath it is still alive, if there is brown it is dead.

13. What can you do to manage windmill grass?

A: Windmill grass is a perennial weed. You can use roundup and overseed or use a product containing mesotrione or Tenacity that will not harm your turf. Use the Tenacity in the late spring.

14. This caller wanted to know what to use for a pre-emergent herbicide in a strawberry patch?

A: Preen that is labeled for use in a vegetable garden would be allowed in a strawberry patch. The best control for weeds in strawberries would be to use mulch.

15. Can you use plants to repel insects?

A: Some plants may deter a few insects for a short time, but no, the plants are not concentrated enough to work against the insect pests.

16. A caller has an arborvitae that turned brown on the North side last fall. Will it be ok?

A: This could be due to bagworms or due to environmental stress. Arborvitae trees don’t like the sudden cool down in the fall and it can cause part or all of the plant to die quickly. Unfortunately, if the tree has turned brown all the way back into the trunk, the tree will not regrow on that section. Removal and replacement may be a better option for this plant.

17. This caller wanted to know when they can reseed their lawn and with what?

A: Mid to late April is the best time to reseed a lawn in Southeast Nebraska. Reseed with 100% Turf-type tall fescue or 100% Kentucky bluegrass or a 50% mix of each.

Squash bug-NH-pic monkey

18. A caller asked what to do about squash bugs in their vegetable garden?

A: Fall sanitation and cleaning up the garden will help a lot to reduce the eggs in the soil around your garden. When they do start coming out in the summer, you can use sevin, eight, or bifenthrin to control them. You will have to spray every 10-14 days through the growing season. Watch the Pre-Harvest Interval to know when you can harvest after spraying a chemical on your plants. You can also smash or remove the eggs you see which are tiny, football-shaped bronze colored eggs on the underside of the leaves typically found in the crotch of the leaf veins.

Yard and Garden: July 8, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for July 8, 2016. 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 5, 2016. 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, Viticulture Specialist for Nebraska Extension with Guest Intern Vivian from China

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/9b24 and be entered to win a free plant book or some free UNL gifts.

1. The first caller of the day wanted to know if they can prune the Cleveland Pear tree that has branches that are low and too tight to the trunk?

A. The best time for pruning a tree like this would be while it is dormant. For a situation like this where the caller is only removing a few branches to help with the growth of the branches and to reduce future problems with the tight branch arrangement it would be fine to remove them now. It would be better to remove branches like this before they break in a storm due to weak attachment to the trunk.

2. A caller has Anjou pear trees that were planted in 2013. Now the bark from the graft union up about 10-12 inches has the bark peeling and now has some black leaves. What would cause this?

A. This would be from sunscald. There is no way to fix sunscald once it occurs. Don’t paint the wound with anything, allow it to heal itself. The black leaves could be due to fireblight. You can cut 6-8 inches past the diseased portion of the limb to cut the fireblight off the tree. The black could also be anthracnose which is not damaging to the plant and there is no need to spray anything for anthracnose.

sunscald-bugwood

Sunscald Photo by William Jacobi, Colorado State University, Bugwood.org

3. This caller has an oak tree that is dripping sap on the vehicles parked under it. What would cause this?

A. Aphids feeding on the leaves of trees will excrete honeydew that can drip on vehicles underneath the tree. Aphids are not very damaging and have a lot of predatory insects that feed on them. They can be sprayed with sevin or eight or another general insecticide, but they should fade out on their own with predator insects.

4. A caller has blue spruce trees that look dirty but the tips are still green. What would cause this?

A. This is most likely due to environmental stress from the heat and humidity. If the ends of the branches are still green, the tree will be fine. Make sure your tree has a mulch ring around it and that you keep it well watered in the heat of the summer.

5. This caller has a patch of lilies where a quarter of the patch has only grown to be about 6 inches tall for the past 2 years. The rest of the patch looks good, but this area doesn’t look healthy. Can these be improved?

A. This could be due to hardiness in some varieties that are only suitable for our environment for a couple of years. It also could be due to some bulb mites. It would be a good idea to dig up some of the bulbs to see if they have any damage on the bulbs.

6. A caller has a pine tree with a lot of sap on the branches and the grass in the lawn won’t green up. Why is this?

A. Woodpeckers or insects feeding on a pine tree can cause sap to leak from the wounds left behind. The insects can be controlled with bifenthrin or permethrin (eight). If it is woodpeckers, the damage is minimal and will not cause any problems to the tree. Check how much water the lawn is actually receiving by using catch cans during the water intervals normally followed. Lawns need 1 1/2 inches of water per week. If the water is fine, there are a lot of fungal diseases in the lawn, it could be one of those. Fungal diseases in the home lawn are usually sporadic and therefore don’t require fungicide applications.

7. This caller lives on an acreage surrounded by farmground. She is considering growing grapes on this large plot of land. Are grapes easy to grow and would grapes have a benefit to the wildlife in the area?

A. Grapes are a large commitment, especially if you plan to sell products from them. You can be successful with only a few plants for the family to use for grape production. A few good choices for this area would include Frotenac or Valiant. The first year the grapes would need extra care, but after that they would be more self-sustaining. Deer will feed on the foliage. If you decide to grow your grapes for commercial use, register  your acreage with the driftwatch website at  www.fieldwatch.com to help avoid problems from drift since grapes are very sensitive to drift damage.

8. A caller has strawberries that were planted and now have very small fruits and the plants are not making runners.

A. Everbearing strawberries are typically very small for fruit size. You might try planting some newer varieties that are June bearing to get larger fruits. Some good choices would include honeoye or albion or sparkle.

9. This caller has an ash tree that is 7 years old and the tree snapped off in the wind. There is mold in the trunk and it is suckering. What can be done to plant a new tree?

A. You can get a company to come in and grind out the stump or rent a stump grinder to do it yourself. The suckers that keep growing back will continue to for a few years, they can be cut out and treated with a roundup or 2,4-D product. You can plant a new tree within just a few feet of the old tree, since this wasn’t a very large tree yet.

10. A facebook photo came in with a odd structure that appeared by a tree. What is this?

A. This would be a stinkhorn fungus. They are not harmful to the plants growing in the area. There is not control other than mechanical removal of the fungus. Do not eat these as they are not edible, they would be a poisonous mushroom.

DSCN6327

Stinkhorn Fungus

11. The last caller of the day has tomatoes in a raised bed. When they ripen for harvest, the end of the tomato seems blighted. What would cause this?

A. This is blossom end rot. It is a calcium deficiency that develops in our plants in drought situations because calcium is only available to plants after it has been dissolved in water. There is no control for this, it should only last for a few weeks early in the growing season and then the plants should grow out of it.

Yard and Garden: June 3, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for June 3, 2016. 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 5, 2016. 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, Lancaster County Extension

1. The first caller of the day has strawberries that are all developing but they are rotten fruits. What would cause this and can it be fixed?

A. This is probably due to a fruit rot disease that is caused by a fungus due to the high rains this year. At this point in the season, fungicides will not help and you will not get much of a crop from these plants. If this is a problem seen every year, a liquid copper fungicide can be applied next year. You should start spraying the plants at petal fall right after the blooms finish next season. To help with this disease, also use a mulch around the plants and avoid overhead irrigation.

2. A caller wanted to know if wildflowers do better where grass doesn’t grow very well? Can he still plant wildflowers now?

A. Wildflowers don’t really do better where grass won’t grow, but the area to plant wildflowers does need to be prepared for the wildflowers. It is best to clean up the area with a glyphosate product, such as Roundup, then till the area up and seed the wildflowers. This can still be done now, it will be fine through most of the spring and fall months. Unless you are planting annual wildflowers, which will reseed for each year, you will not get many blooms this growing season. It will take a few years to get the wildflowers going well and weed control will be necessary. If you don’t want any grasses growing in the wildflower patch, you can use grass herbicides and not harm the wildflowers.

3. This caller has pansies that are being eaten, the small white dots are on the underside of the leaves. What would this be and how can they be controlled?

A. This could be aphids which can be controlled with eight, bifenthrin, or malathion. However, pansies are nearing the end of their life as they are a cool season plant. So you could just remove the pansies and plant something else to reduce the problem and not have to use pesticides.

4. A caller has been dealing with high populations of grasshoppers recently. They are feeding heavily on his potatoes. What can be done to control them?

A. In the potatoes, you will need to use an insecticide labeled for use in a vegetable garden such as bifenthrin, sevin, or eight. It would also be helpful to keep the grass mowed around the garden and to treat it with some of these insecticides. Also, grasshoppers are often found in roadsides, so be sure to spray these areas as well to help reduce the overall population.

5. When can peonies and iris be cut back?

A. You can cut off the flower stalks on both of these plants as soon as they are done blooming. However, you need to wait until they die back in the fall before removing any leaves from the plant.

6. This caller has a lawn with patches of darkened areas throughout it. What would cause this?

A. Walk through the dark areas to see if the blades pop back up. If the blades stay down after they are walked on and you can see you footprints, it is due to drought stress and the lawn needs to be watered. Also, look closely at the leaf blades to see if there are small, black/gray structures like tiny balls. This would be slime mold which is also showing up in the lawns now. Slime molds are not a serious problem to the lawn.

7. This caller has a weeping willow. He wants to know if he can prune the branches up so he can mow underneath it?

A. Pruning for a weeping willow is best done in the fall but it can be done now. You can limb it up and shorten some of the branches to make it more accessible for mowing. However, don’t remove more than 1/3 of the plant in one growing season.

8. A caller wanted to know about mosquito control. He had found a recipe online that was with household items and it claims to control mosquitoes for 80 days. Will this work?

A. No. The best control for mosquito control outdoors only last for a few days. It is best, if you are having an outdoor BBQ, to spray the lawn and shrubs around the lawn up to 2 days prior to the event for management of mosquitoes. You can use sevin or eight or malathion or bifenthrin for control. Be sure to use bugspray containing DEET while outdoors. Also, make sure you have no standing water in your lawn to reduce the population of mosquitoes.

Roseslug Collage

Rose slug on the leaf on the left, damage from rose slugs on the right.

9. This caller has roses that have leaves that look shredded or with many holes in them. What can be sprayed on the roses to help them with this problem?

A. This was brought into the extension office later for identification. It was rose slugs. These are small, translucent, green caterpillars with a brown head found on the underside of the leaves. Rose slugs are actually the immature of a sawfly and not a slug at all. They are mostly damaging to the aesthetics of the plant and are not that harmful but they can be treated with sevin dust on the underside of the leaves if they are heavily damaging the plant. Be careful to not get the sevin on the flowers to not harm bees.

10. What digs holes 6-7″ deep straight down into the mulch around trees?

A. This could be either squirrels or skunks or possums that would be digging for insects. Clean up around the tree to help deter the animals.

11. The final caller of the day has a cedar windbreak with a lot of scrub trees growing among the cedars. How can those be controlled?

A. It is best to just cut off the scrub trees and do a stump treatment with a concentrated roundup product. Spraying in the windbreak can damage the cedar trees.

Yard and Garden: April 15, 2016

Yard & Garden for blogThis is the Q&A for the Yard and Garden show for April 15, 2016. 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 5, 2016. 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: Jeff Culbertson, UNL Landscape Services

1. The first caller of the day has asparagus that she planted last Spring. What needs to be done with the plant now?

A. Light harvest can be done the second growing season and then full harvesting can begin the third season. Mulch it now to keep weeds down, herbicide sprays are not able to be safely used too close to growing asparagus. Cut the plants back in the fall after they have grown well all season. Fertilizer can be applied now or in the fall.

2. How do you control moles in the lawn? How do you control grubs in the lawn?

A. For mole control, see this guide from the Internet Center for Wildlife Damage Management: http://icwdm.org/handbook/mammals/mam_d51.pdf Make sure that you have found an active run area before implementing any traps by stomping the mounds down for a couple of days prior to setting the trap. For grub control, the best option is to apply a product containing Imidacloprid around the third week of June.

3. This caller from the Southern part of the United States said that it is difficult to grow asparagus in the south. Is this due to the lack of dormancy in the south compared to what we have in Nebraska?

A. Yes, asparagus would need to have a rest period that occurs during our winter in Nebraska. However, the roots are also prone to root rot problems, so it might be that your soil could be too high of clay that isn’t allowing the asparagus roots to dry out enough.

4. Another caller has Iris that they have sprayed with Sevin for iris borers that are always a problem. Is this the best product and when should she be applying it? Also, she applied lime to the plants and now they are a lime green color instead of the deep green they are supposed to be. What is causing this discoloration?

A. Lime is used for acidic soils to raise the pH. In Nebraska, most of our soils are heavy clay and therefore already have a high pH. The addition of the lime to the soils in this case is causing chlorosis on these iris plants. It will work through over time, but for a couple of years the iris may look a little tired. The Iris borers have not shown up yet, but a treatment with an imidacloprid, permethrin, or bifenthrin soon or just as the larvae come out would be ideal for control.

5. This caller is wondering what the timing is for fertilizer with crabgrass pre-emergent herbicide? He is also wondering how to control bindweed in bromegrass?

A. Anytime in the next week or 2 would be ideal for fertilizer and crabgrass pre-emergent use this year. The soil temperatures are at 54.9 degrees Fahrenheit for the 7 day average. Crabgrass will germinate at temperatures between 55-60 degrees Fahrenheit, so you can begin applying your control methods anytime now until the end of the month for best control. The bindweed can be controlled with trimec  if used 2-3 times per summer. Keep the bindweed mowed to prevent flowering from occurring to reduce the amount of seed left in the grass.

6. A caller has cedar trees that were recently pruned from the bottom up. What would be a good grass to grow under these trees?

A. A fescue grass would grow well in this shady environment. Also, a nice groundcover such as purple leaf wintercreeper would be a good alternative to grass to reduce mowing under the tree and to grow better in the shade of the tree.

7. This caller from Hickman has a cherry tree. Every year they mow off many “little trees” that grow up and around the cherry tree. Is there anything else to do to reduce the occurrence of these trees?

A. Suckering occurs with many different tree species. These suckers may be growing off of the roots of the main tree so chemicals should not be used or else you may end up killing the desired tree as well. Cutting them off or mowing over them before they grow too large would be the best options for control.

8. This caller has fruit trees. He is wondering if a product called “fruit tree drench” for insects would be ok?

A. Not knowing the active ingredients in this product makes it hard to answer the question. Systemic insecticides are not usually safe for use in plants that are edible because a systemic insecticide will move throughout the entire plant, including into the edible parts. It is suggested to do more research on the safety of the product or to move to a spray type of insecticide that is not systemic to reduce the health hazards that may be a problem with systemic insecticides.

9. Another caller has an apple tree that is 7-8 years old. The last 3 years it has produced nice apples but they are rotten inside. Now there are not many apples that are not rotten on the inside. What can be done for this?

A. Sanitation is going to be key for controlling this disease, known as black rot of apples. A orchard fruit tree spray program can be used to minimize the damage as well. Pruning may need to be done to remove any branches that are dead or diseased.

10. A caller wanted to start a new strawberry patch. How far should the plants be spaced in the garden and what should be done to the soil for improvements?

A. Till in compost and topsoil for increased organic matter and reducing compaction in the soil. Space the plants 1 foot apart.

11. This caller has a maple tree that is not budding out and has not yet lost the leaves from last spring. Will it survive?

A. Some maples, such as the sugar maples, have not yet leafed out for this spring. Use the fingernail test to scratch the bark lightly on smaller branches to see if there is green underneath the bark. Green under the bark means the tree is still alive and waiting to come out of winter dormancy, brown under the bark means it died over the winter.

12. A caller wants to know about the “spray on grass”. Will it work for overseeding?

A. Should work ok, but check with the types of grass seed included in these cans. Many of these mixes have perennial rye which doesn’t last long in Nebraska environments. Also, check for the amount of weed seed found in the mixture.

13. Is it too late to thin Iris plants?

A. The best time to transplant and divide iris plants is in the fall. Use a garden fork to lift them from the ground. Look for borer holes, and then replant them making sure to not plant them too deeply.

14. What is the best advice for improving soils for growing watermelons?

A. Lighter soils are best for growing watermelons. Add compost to improve the fertility.

15. A gentleman has cherry trees, apricot trees, and peach trees. What type of mulch should be applied to help keep the trees watered?

A. Organic mulches should be used, such as the wood chips. They need to be applied at a uniform depth of 2-3 inches in a ring around the trees that is at least 2-3 feet wide around the tree. Water the trees for about 45 minutes every 10-14 days, more may be necessary during the hot, dry periods of the summer. Use a soil probe or long screwdriver to see if the trees need water. Push the probe into the soil up to 12-18 inches deep, if there is resistance any time while pushing into the ground, the trees need water.

grape hyacinth, ricky layson photography, bugwood

Grape Hyacinth photo from Ricky Layson, Ricky Layson Photography, Bugwood.org via Creative Commons License.

16. A caller has grape hyacinth growing in her lawn. What can be done for management?

A. Mow it off. This is a short lived annual plant that is close to the end of its lifetime for this year. There is no need to use chemicals to control this plant.

Yard and Garden: April 24, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for April 24, 2015. 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, 2015. 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: Jeff Culbertson, Assistant Director of UNL Landscape Services

1. This caller wants to know why the water in her rain barrels is turning green and how to fix that problem?

A: The water should be used sooner from the rain barrels and not allowed to sit in it for very long periods of time. There is a great NebGuide on ‘Rainwater Harvesting with Rain Barrels‘. Algae can sometimes appear and can be reduced by:

  • Limit nutrient build-up in the barrel by reducing the amount of sediment and plant debris entering the barrel. These are sources of nutrients like phosphorous and nitrogen that promote algae. Clean roof gutters at least annually. If hosing out the roof gutter, remove the rain barrel before cleaning. Consider installing gutter screens along with using screens/filters before the barrel inlet.
  • Clean the barrel at least once a year to remove sediment.
  • Use dark-colored, painted, or opaque barrels to limit light.
  • Place rain barrels in a shady location when possible.

2. This caller had a willow that is leafing out from the bottom without any growth at the top of the tree. Is this normal or what is wrong with the tree?

A: This could be due to dieback from the winter which is being seen throughout the landscape this year. It is still early in the season so the tree could come out of it, so give it time to see if it comes back. Scrape off some of the bark with your fingernail to see if underneath is brown or green. Green is healthy growing tissue, brown is not. If it seems to be dead later in the season, you can prune out some of the dead branches and the tree may still survive.

3. When is the best time to dig cedar trees from the pasture to transplant them into a windbreak?

A: Now would be a good time to do this. Make sure they are small trees and that they are protected from deer and rabbits in their new location. Keep them well watered.

4. What is a good rhubarb fertilizer?

A: 12-12-12 or 10-10-10 would be a good general fertilizer to use or manure in the fall.

5. This caller wanted to know if Ponderosa Pine was still a recommended tree due to the threat from Pine wilt?

A: Ponderosa Pine is only mildly affected by pine wilt. Very few ponderosa pines have been killed due to the disease. It is still on the list of trees from ReTree Nebraska. Watch these trees for tip and needle blight, 2 common needle diseases, that can be easily treated with fungicides.

6. A caller has 2 trees in her windbreak that were planted about 8 years prior to a storm that has caused them to lean now. It has been a couple of years since the storm, but the trees are still leaning. Can this lean be fixed?

A: They will grow straighter over time and eventually straighten up somewhat. If the lean is too much, they will not overcome that.

7. This caller has been gradually replacing a plum hedge with Lilacs. What can he do to prevent disease and insect problems in the lilacs?

A: After about 2-3 years of initial growth, begin annually removing the largest, woodiest stems from the lilac shrubs. This will help keep the shrubs with younger, better producing wood and it will help keep the borers and scale away from the plants. As for disease control, just be sure to space the lilacs properly. Most full sized lilacs will get 3-4 feet wide so space them about 4 feet apart to reduce the overlapping of the branches and leaves which can lead to more disease problems.

8. A caller has a large asparagus bed that wasn’t cleaned up last fall. What care can be done for the asparagus now and in the future?

A: It would be best to clean the asparagus up one time a year, either in the fall or late winter just before spring growth begins. To help reduce weeds after that, spray the weeds while they are green and the asparagus hasn’t emerged for the year yet in the spring. Fertilize the planting bed either in the spring with general purpose fertilizer or in the fall with manure or both times.

9. This caller has a rose bush on an old property and wants to know how to propagate it or transplant some of it to their home?

A: Remove and transplant any suckers on the plant will work on an older rose variety that wouldn’t have been grafted. Anytime now is a great time to transplant a rose bush.

10. This gentleman has French Dwarf Lilacs and he was told not to trim them out. Is this true?

A: These can be cut back or caned out annually to keep them smaller and to help them produce more flowers.

11. A caller had stumps from trees that were cut down last year. The stumps were treated with Tordon. Can he use the mulch they will make from the stumps in his landscape or would the Tordon still be in the wood chips?

A: Wood chips that were treated with Tordon could still have that pesticide residue in the wood chips. It should not be used around plants. Disclaimer: Tordon should NOT be used in a landscape setting, it is against label instructions. Always read and follow pesticide labels. Remember: The label is the Law.

2015-04-15 11.03.06

12. This gentleman had cedars with the tips of the branches turning brown this year. What is causing that and what should be done for it?

A: This could be winter kill as that is showing up in many juniper species this spring. It may also be Kabatina, a disease of junipers. The brown can be cut out of the trees at a branch crotch. The trees should live.

13. This caller was looking for a shade tree for her front yard that is fast growing, stays around 20 feet tall and possibly provides flowers or good color to the landscape.

A: Chanticleer or Cleveland Select Pear would be good for spring color. Crabapples can also grow to 20 feet tall and would provide a great deal of color and scent in the spring. Japanese Tree Lilac is another good choice for a smaller tree.

14. This caller is planting strawberries and raspberries. What kind of care would she need to provide them?

A: Here is a good guide from Sarah Browning on Summer Berries-Raspberry and Blackberry to guide you through the raspberries. Heritage is a good raspberry variety choice. This is a good guide from Lancaster County Extension on strawberry care called Growing Strawberries.

15. This caller has a pin oak tree that has iron deficiency. She has used the iron plugs on the trees but she is curious if there is another choice that will work better and for a longer period of time on the pin oaks?

A: This tree will continue to have problems once it starts to show signs from Iron Deficiency and it will eventually die from this nutrient problem. She can try to have a professional due trunk injections which will last longer each time, but this will have to be continued for the remainder of this trees life.

16. This caller wanted to know how to prepare cut lilac flowers to last longer indoors?

A: Cut the flowers before they have opened on the plant. Make a new cut on the stem and change the water daily. Use a preservative in the water. The preservative can be either a store bought product or make your own mixture by dissolving 4 heaping teaspoons of cane sugar and 2 tablespoons of white distilled vinegar in one quart of warm water.

17. This caller wanted to control the dandelions in his yard and not the clover. Can a chemical be used for this?

A: Using spot sprays of 2,4-D when the weather is calm and the temperatures are below 80 degrees Fahrenheit for the day of application and the 2 days following would help reduce damage to the clover. The other option would be to dig or hand pull the dandelions. The chemicals that would work for dandelion would also work to kill clover.

Happy Arbor Day! Plant a Tree!!

Image Courtesy of Steven Katovich, USDA Forest Service, Bugwood.org

Image Courtesy of Steven Katovich, USDA Forest Service, Bugwood.org

Yard and Garden: April 10, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for April 10, 2015. 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, 2015. 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: Dick Campbell from Campbell’s Nursery in Lincoln, NE

1. The first caller wanted to know when to trim trees?

A: This depends on the type of tree to be trimmed. Oaks should not be pruned from April 1 through mid July to avoid susceptibility to Oak Wilt, a deadly disease that affects oak trees. Maples and birches will bleed sap excessively if pruned right not. This bleeding is not damaging to the tree, but it can be messy. Otherwise, it is good practice to prune deciduous trees during the dormant season so you can see through the trees to any crossing branches and air flow through the canopy.

2. This caller has a peach tree that produces too well. He wanted to know how to make the tree produce less fruit?

A: Fruit thinning should occur on fruit trees to help avoid branches breaking later in the season if they get too heavy due to fruit. The fruit on any fruit tree should be spaced 6-10 inches apart, leaving only one fruit on the branch every 6-10 inches. This will give you nice sized fruits that will not weigh down the branches.

3. A gentleman has ash trees that are loosing bark off the trunk. What would be causing this and how can it be fixed?

A: This could be caused by frost cracking. Frost cracks occur due to rapid temperature changes during the winter months. There is no cure for a frost crack and they may never heal over. Some trees may be able to close this wound, but if not it is an area where decay can enter the tree, as well as insects and diseases.

4. This caller uses ammonium sulfate on their lawn. Can this harm his lawn?

A: This can be harmful to the lawn, if the fertilizer is not spread uniformly throughout the lawn. If it gets concentrated too high in one are of the lawn, a burn can occur on the turfgrass. Otherwise, it will work fine as a quick release fertilizer.

5. Another caller has a steep slope in full sun in his lawn. What is a good perennial groundcover to use that does not have to be mowed?

A: Buffalograss is a good low management, perennial groundcover for full sun that wouldn’t have to be mowed. There are a lot of new varieties to choose from including, the newest from UNL, Sundancer Buffalograss that is darker green, has a denser canopy, and establishes faster. For more information on buffalograss care, see these UNL NebGuides: Establishing Buffalograss Turf in Nebraska and Management of Buffalograss Turf in Nebraska 

6. This caller had old Lilac bushes used as a hedge. She had cleaned them up and noticed there was a lot of dead branches and some new growth of branches. What should she do to clean them up and get them growing nicely again?

A: Prune out the dead canes, leave as much of the new, healthy growth as possible this year. Over the next few years, she can prune more of the larger, older canes out to bring it back to healthy growth. Don’t use a rejuvenation pruning with these lilacs because the older they are the harder it is for them to come back from such a drastic pruning. Watch out for borers and use systemic insecticides if holes are found at the base of the shrubs.

7. This caller had locust trees in the roadside. What should she do to get rid of them?

A: Cut the trees down and do a stump treatment with herbicides labeled for use on trees in a roadside.

8. A caller wanted to know what to do when planting new strawberry bushes and if they can be planted in containers? He also wanted to know what to do with shrub roses that grew taller than they should have, how much can he prune off of those roses?

A: Plant the strawberries to where the crown of the plant is just at the soil surface. Plant them 1 foot apart within the row and space the rows 4 feet apart. After planting you can use a pre-emergent herbicide on them to reduce weeds. Yes, they can be planted in a container, but that container will need to be protected through the winter months to get the strawberries to overwinter. As for the roses, you can cut those back to 6-8 inches tall rather than just taking a few inches off of the top. This will give you new growth that will produce more flowers throughout the entire shrub rather than some flowers just on the ends and sides.

 9. This caller had bagworms on his blue spruce in the past. He has now noticed that the top few feet of the spruce has died. Is this due to the bagworms? How can this be fixed?

A: This would be from a fungal disease called canker that is very common to spruce trees. From the point of the canker and anything above it, the tree will die and sap will flow from that canker location. There is no cure for canker, but the infected area of the tree can be removed to a location below the canker. It may regrow a new leader, but it may also continue to grow with a flat top. Bagworms can be treated with Bt, carbaryl, permethrin, or malathion around the third week of June or when the bagworms are immature and crawling around on the tree.

10. A caller wanted to know when to prune shrub roses? She also has a weeping white birch, when should this be fertilized?

A: Shrub roses can be pruned now. The weeping white birch should be fertilized just before they start to send sap up throughout the tree, which will begin soon. Watch all birch trees for borers, as this is a common pest in birches. Systemic insecticides, such as those containing imidacloprid, can be applied in the spring to help with borers in the tree.

11. This caller had apple trees that are 15 years old. When should they be sprayed for insects and diseases and what should they be sprayed with?

A: Orchard fruit tree sprays can be applied to all fruit trees. These have an insecticide and a fungicide to help with many problems that fruit trees face in Nebraska. This product should be applied at petal fall and every 10-14 days following. Be careful to not use insecticides on fruit trees while the flowers are blooming so no harm comes to the pollinators helping fruit development.

12. A gentleman wanted to know how to control Star of Bethlehem?

A: Spray with a combination product, such as Trimec. September 1st would be the prime time to do this so that the chemical will be taken into the bulb when the plant is taking nutrients into the bulb to help it get growing the following spring.