Yard and Garden: May 19, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for May 19, 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: Jim Kalisch, Insect Diagnostician for Nebraska Extension

If you enjoy reading my Q&A from the show each week, take my quick survey at: http://go.unl.edu/44qr and be entered to win a free plant book or some free UNL gifts.

1. The first question of the day was from a gentleman wondering how to tell when to water his self-watering containers? There is no viewer or gauge to show the water level on the outside of the container.

A. Because a self-watering container is continually watering the plants in it, it can always be refilled. In this case, this container will keep your plants watered for at least a week to two so, they should be refilled before they completely dry up. I would suggest refilling the reservoir every week to 10 days.

Bagworm4

Bagworm

2. A caller has bagworms in their cedars. What is the best way to see them before they get too big to treat?

A. They haven’t hatched yet this year. Mark the branch you have a living bag on with flag tape to check the same bag every week from now until they hatch. You can also place a few bags in a container and keep it in the tree to see when they hatch in the container. Wait a couple of weeks after the initial emergence to ensure that all of the bagworms have hatched before spraying. The bags in the shade will take longer before they hatch. Once they have hatched, Bt is a good insecticide to use when they are young or you can use a product containing bifenthrin in it for longer lasting control.

3. This caller is wondering what types of problems we can expect in the garden, lawn, and trees this year due to the excess rain?

A. The rains in the spring tend to lead to more fungal diseases this time of the year, but they are not terribly harmful and many should fade out as the summer heats and dries up. Many things to watch out for would include fungal diseases in the lawns and trees. We are already seeing Peach Leaf Curl, different fungi in blue spruces, anthracnose on the leaves, and mushrooms popping up in our lawns. We will also see more problems from earthworms and fungus gnats which are mostly nuisance problems.

2015-09-22 18.45.39

Squash bugs on a zucchini

4. How do you effectively control squash bugs in the vegetable garden?

A. Squash bugs are difficult to control in our cucurbit vegetables including zucchini, squash, pumpkins, gourds, melons, and cucumbers. The best option is to kill the adults when they first emerge to manage the population before it explodes. Watch for the eggs as they develop on the underside of the leaves to destroy them before they emerge. Switch to other chemicals for management besides just using “Sevin” for control, which they are becoming resistant to. There are also lures that can be used for them which might help early in the season.

5. A caller has an Oregon Trail Maple that leafed out early this spring. Now the leaves are slightly cupped and turning yellow along the edges. What would be causing this?

A. This sounds like frost damage. If the leaves came out early, they may have been nipped by a light frost in late April. We are seeing this problem throughout many trees and shrubs this spring. The leaves may drop entirely from the tree, but the tree will then push secondary buds to produce new leaves that are not injured.

6. This caller wants to know how to propagate a lilac and a hydrangea.

A. For lilacs: A cutting can be taken from the shrub. Cut off a small, pencil-sized, branch and place it into rooting hormone than plant it into a pot of gravel that is kept moist. Once roots have formed, the plant can be transplanted into the ground. They can also be propagated through a process called layering which is where you bend a flexible branch down to the ground and plant it to allow roots to form on the branch while it is still attached to the main plant. Once roots form, cut it from the parent plant and transplant it. There is more information on this in the NebGuide: Lilacs

Hydrangeas can also be layered to produce new plants or they can be divided. It is too late to do the division this year, but early next spring you can dig up the plant and use a spade to divide the main plant and replant the pieces. Depending on the side you can get 2-4 pieces from a divided plant.

7. Is cedar-apple rust damaging to cedar trees?

A. Cedar-apple rust shows up in the spring on cedar trees as a orange, slimy, ball with horns. This is the gall that opens up with rains in the spring. Cedar-apple rust is not harmful to the cedar tree, it just uses the cedar trees as an alternate host through the winter. When these galls are seen on the cedar, that is the time to spray any susceptible apple, crabapple, pear, or hawthorne tree to avoid damage to them. For more information view this NebGuide

8. This caller has a pink peony that hasn’t bloomed well this year. There is some discoloration and fuzzy appearance to the leaves and buds. What would cause that?

A. This sounds like botrytis blight, a common fungal disease to our peonies. It is not very harmful to the plant itself, so it is not necessary to control it. In the fall, make sure you remove and destroy all of the plant material to reduce the spread to your plants next spring.

9. A caller has a Chanticleer Pear with leaves that have black spots on them and the top isn’t leafing out this spring. What would cause that?

A. This could be due to frost damage as well. Or check the tree for oozing sap along the trunk or branches. The damage could be from borers. It might also be from fireblight which would cause the leaves to turn black on some branches where the end of the branch hooks over like a shepherds crook. Fireblight is likely since this showed up in the tree last summer. If it is fireblight, prune out the infected branches and dip your pruners into a bleach water solution in between the cuts.

10. This caller has roses that had dieback from the winter. She pruned them off in early April and now it looks like the only live growth is coming from the ground. What is wrong with her roses and will they come out of it?

A. Unfortunately, these roses seem to have more dieback from the late frost we saw in April. If there is no green growth showing up on the main part of the plant, it is likely that it has died back. The roots would be shooting the new growth from the ground, but that is not going to be the same type of rose that you had there before because our roses are often grafted. The growth from the ground would be from the rootstock so it wouldn’t be the size and color of rose that was originally purchased. Unfortunately there is nothing that can be done about that. It might be time to go and choose some new rose colors for your garden.

11. A caller has a river birch tree that dropped its leaves in the summer last year. The leaves now are yellow and only the top half of the tree has leafed out this spring. They are 20 year old river birch trees. What would be causing this problem?

A. Look on the branches of the tree for signs of bronze birch borer. Some of the signs of this borer would be rippling on the branches or holes in the stem or branches. If you find the signs of bronze birch borer, you can treat it now with a borer spray or with a systemic insecticide.

12. A caller has a river birch tree that was growing in a clump and one of the trunks of the group died out. Should it be removed now?

A. Yes, any dead part of a tree should be removed as soon as it is noticed. A large part of a river birch, like this, could be hazardous if left standing after it dies. Unfortunately, when that branch is pruned off decay will likely begin but there is no way to prevent that at this point. This will likely be a large portion of the tree removed and that large of a pruning cut may not ever heal over entirely. When a branch doesn’t seal up, decay can get into the tree causing more damage. We don’t advise painting the stump with anything.

13. A question came in via email regarding a red twig dogwood. This dogwood is 4-5 years old and has never been pruned. Following the storms this week, some branches are falling over blocking a mowing path. Can those be pruned now? What should be done with it in the future?

A. Broken branches can be removed at any time. If these are just bending over, they could still be removed if necessary, but they may pop back up to their normal standing position. For future, red twig dogwoods should be pruned to the ground every 3-5 years to maintain that good red color on the twigs. They should be pruned in the late winter to early spring.

14. A lady called who has a Cranberry Bush Viburnum that has dead branches in it. Can those dead branches be pruned out now?

A. Yes, dead branches should always be removed when they are noticed. Check to ensure that these branches didn’t die due to Viburnum borers, if so, treat with a borer spray or systemic insecticide.

15. The last caller of the day has 2 different plants that have problems. A maple tree has brown specks on the leaves and they are falling off the tree. A Peony bush has leaves that are turning yellow along the edges of the leaf. What would be causing these two problems?

A. These both sound like frost damage. They will both be fine. The maple may drop all the damaged leaves and put on new growth.

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Yard and Garden: May 12, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for May 12, 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: Dr. Paul Read, Viticulture Specialist from UNL

1. The first caller of the day called to ask when is the best time to take cuttings from grape vines and how should it be completed?

A: To take a cutting, when you cut off the dormant growth from the previous year, you can take those branches and put them in moist sand to get them to root. After the last spring frost of the year, you can plant those rooted branches outdoors. When you do this method, you need 2-3 buds on each branch. Put at least 1 bud into the ground and have 1-2 buds out of the ground for leaf growth. At this time of the year, you can complete the layering method of propagation. For layering, just bury a few of the longer branches that are still attached to the vine. Once they root, you can cut them from the main plant and replant somewhere else.

2. A caller has a 7 year old peach tree that is dropping leaves like it is fall. What would be causing this to happen and can it be corrected?

A: This could be abiotic stress due to unfavorable environmental conditions. It could also be from peach tree borer. Look along the trunk for small borer holes or sap oozing from branches or the trunk to know if it is the borer. If borers, spray the trunk with a fruit tree insecticide spray. If it doesn’t seem to be from insects, keep the tree healthy through a good mulch ring and regular watering as needed when natural rains are infrequent.

3. This caller has 2 concord grapes that were producing well last year but were taken by the birds before they could be harvested. How can you keep these birds away?

A: Bird netting over the plants to keep the birds out is the only good, effective method of managing birds in grapes.

This caller also wanted to know what is wrong with her peach trees? She has 2 peach trees that are 9-10 years old that now have an orange sap oozing from the trunk.

A: This would be from gummosis, a fungal disease common on peach trees. There is no real cure for this disease, it is just best to prune out the small branches that are affected and cut 6-8 inches below the infected area. Dip your pruners into a bleach/water solution between cuts to prevent further spread of the disease. It could also be from peach tree borers. In that case, use an insecticide labeled for use on peaches for borers.

4. A caller has a row of cottonwoods but there is one tree in the middle that always has yellow leaves rather than green leaves. What is wrong with it and can it be corrected?

A: This is most likely due to an iron deficiency in this tree. That can be corrected by having a certified arborist come in to do a trunk injection. The granules or stakes around the tree are not very effective. Often, iron chlorosis is a sign of other problems with the tree and may be the beginning of the end for the tree. That being said, many of our trees live many years after developing an iron deficiency and some just need an iron injection every 5+ years to live a long and happy life.

Tree hole for blog

Photo of the damage occurring to the Maple tree.

5. A caller has some maples that were recently pruned and the branches had a fungus and some white powdery substance in them when the branches were removed. What is wrong with them and do they need to be removed?

A: This caller emailed me with photos of the problem so I could see for sure what is wrong with the plants and if it can be corrected or if it is a safety issue. Unfortunately, this does look like decay in the tree. Decay within the interior of the tree can be dangerous for when it may fall, the tree is not stable when it has decay. I would guess that the tree has a large limb that was removed at one time and it was too big or improperly cut and now there is a large hole leading into the tree. I would get a certified arborist out to take a look and possibly remove the tree.

6. This caller has a cedar windbreak and would like to plant crabapples. Can crabapple trees grow near a cedar tree?

A: Yes, you can plant crabapple trees near cedars, just make sure that you select a variety that is resistant to cedar-apple rust to avoid having to spray annually to avoid the damage from cedar-apple rust.

7. A caller has a blue spruce tree that is 8 feet tall and was planted 14 years ago that died over the winter months. What happened and how can it be avoided in the other trees in the row?

A: This could be due to a canker which is a fungal disease that stops the flow of water and nutrients from the canker point outward and upward through the tree. If the canker occurred on the lower part of the trunk it would cause the tree to die. There is no cure for canker and no way to prevent it. It could also be due to a root issue that could have happened when the tree was planted or in the nursery. The tree may have a root that girdled the stem killing the tree or it may have been planted to deeply. When you remove the tree, look at the root system to see if this was the problem.

8. This caller has small brown circles in the lawn all around a tree. This problem occurs every year later in the summer in the same location of the lawn. What would be causing this and can it be controlled?

A: This is most likely due to summer patch, a common lawn fungal disease that occurs in the mid-late summer. Normally, this isn’t something that is treated for because it doesn’t occur in the same location every year, but for this caller, it does. Management practices in the lawn can help, such as mowing higher and doing core aeration to reduce the thatch layer in the lawn. If necessary, fungicides labeled for summer patch can be used from now until the end of June.

Summer Patch, L. Giesler turf update

Summer Patch in Kentucky bluegrass photo by Loren Giesler, UNL Plant Pathology

9. What is a better species selection than using Bradford pear?

A: Chanticleer or Cleveland Select are better options for pear trees than a Bradford Pear. Bradford pears tend to have narrow branch arrangement that leads to more broken branches from high winds and storms. These two options are better choices because their branches are wider when arranged on the trunk.

10. A caller has a maple tree that is half green and half a much lighter green color. What would cause this and can it be corrected?

A: The soil pH is higher on one side. A disturbance on the one side could cause it to have iron deficiency on the lighter green side. Try to spray chelated iron on the lighter green side to fix the problem.

11. When is the best time to start asparagus?

A: Spring is the best time, from March to April is prime time for planting asparagus crowns. Be sure to still wait 3 years before full harvest begins.

12. The final caller of the day had 2 questions. She had botrytis on her strawberries last year and sprayed a week ago. Does she need to spray again? Also, can an Annabel Hydrangea be planted in full sun?

A: For the strawberries, 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. Annabel Hydrangea is one that prefers partial shade. I would avoid planting it in full sun on the South or West side of a building where it would get too hot.

 

Yard and Garden: April 28, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for April 28, 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: Dick Campbell, Owner of Campbell’s Nursery in Lincoln, NE

1. The first caller of the day has a Lilac that has bloomed in the past, but it isn’t blooming much. It has never been a reliable blooming shrub. What is wrong with it and how can it be fixed?

A: This plant was bloomed a few times in the fall, which would cut off the blooms for the following spring. However, this isn’t the only problem because for the past couple of years they have been better at timing their pruning. A late frost could have hit the blooms causing problems with bloom, it may reduce the overall bloom amount. Also, this could be a nutrient issue. A good fertilizer, such as bone meal, could be incorporated into the soil surrounding the plant to help with the nutrient availability.

2. A caller has ribbon grass that has died out in the center. This dead center has continued to get larger over the years. What can be done about that?

A: This plant needs to be divided. Many perennial grasses will develop a dead center when it is time to dig them up and divide them. The spring is a good time to do this for grasses. Iris plants will do this as well, they are best divided and replanted in the fall.

3. This caller has a weeping Norway spruce that is bending over heavily. Should it be trained to keep it more upright?

A: This is a typical growth habit for a weeping Norway spruce. They bend over more than some of the other weeping varieties. It would be good to put a small stake along the trunk of the tree to support it for more upright growth.

This caller also wanted to know what the timing was for spraying apple trees for Cedar-Apple Rust?

A: Now would be a good time. When the galls on the cedar rust have come out to look like a slimy glob in the spring rains it is time to spray. Those galls have just begun to open up and release the spores. For more information on cedar-apple rust, see this NebGuide.

Photo of Cedar Apple Rust Gall photo courtesy of Mike Lewinski via Flickr Creative Commons License

4. A caller has a cherry tree that has a split going up it and now it has sawdust around it on the ground.

A: Often we see insects in our plants as a secondary problem. What you are dealing with here, is most likely carpenter ants. They have come into the split in the tree and are making a nest in the rotting heartwood. The carpenter ants are not doing any more damage to the tree than what is already done. They can be killed by using an insecticide dust in the tree crack, such as sevin. However, the more concerning issue is the crack in the tree. If the tree is very large it may be a hazard. Tree removal may be necessary. If the crack is not very deep, it could be a frost crack which would be less hazardous.

5. Can you grow English Walnuts in Nebraska?

A: Yes, they can be grown here, it is most likely you will have to plant them from a seed as there aren’t many grown as plants for sale. Check with the Nebraska Nutgrowers Association for more information and seed/plant sources.

6. This caller has a blue spruce that is not growing well. It was planted 17 years ago and hasn’t grown more than a couple of feet in this time. What is wrong and can it be fixed?

A: The tree could be battling with too much brome grass growing around it and competing for nutrients and water. It would be beneficial to kill the brome grass and to add a mulch ring of 2-3 feet out and 2-3 inches deep around the tree to help reduce competition. This also could be a root issue that there would be no fix for. Often times, our trees are planted too deeply or grown in a container too long causing the roots to circle the tree. Once the tree is planted, there is no way to fix these conditions and the damage may not be present in the tree for 10-15 years after it was planted. This could be the case with this tree. Try adding mulch and ensuring proper irrigation through the growing season and it may come out of it.

7. A caller has a redbud that is 8 years old. The branches are dying and there are holes in the trunk. It seems that only one branch is still alive on the tree. What can be done for the tree? Or should it be removed?

A: The holes could be from borers that can be treated, but are often a secondary pest. If only one branch is left alive on the tree, it may be time to replant.

8. This caller is planting a new garden in an area that was a cornfield until this year. What do they need to do to the soil to plant in it?

A: Because this has been used as a crop field, I would advise a soil test to see where all the levels of pH, organic matter, Nitrogen, Phosphorus, and Potassium are at and to ensure vegetable crops will even grow in the soil that has been heavily planted for many years.

9. A caller is cleaning out dead and dying pine trees in a windbreak. Do the stumps need to be removed? What can be done to get it ready to replant?

A: If they are Junipers, or eastern red cedars, they can simply be cut off at ground level and they will not regrow. With some of our windbreak plants, they may need a stump treatment of 2,4-D or Roundup or a mix of the 2 products. If you are planning to plant a new windbreak where you removed these plants, it would be beneficial to grind out the stumps. If there is enough space, you can replant around the old stumps, just stay a few feet away from the stumps left behind if you don’t remove them.

10. What is the best care to give to seedling trees given to students for Arbor Day?

A: Grow the seedling in a pot for a year. When winter comes either plant the pot in the ground with heavy mulch or bring the container into the garage. Next spring, plant the seedling into the ground and protect it with fencing from rabbits and deer.

11. A caller wants to know how to control sandburs and where you can purchase milkweed plants?

A: Sandburs are controlled with crabgrass control products. As a preventer, using crabgrass pre-emergent herbicides will also prevent the germination of sandburs. If they have already germinated and are starting to come up, you can use a post-emergent herbicide for crabgrass such as quinclorac or Drive or Dimension. You should be able to find Milkweed plants at many local nurseries.

12. This caller has a white powdery substance on her peonies. What is it and what can be done for it? Also, she has a cherry tree that was severely damaged from deer, but now there are new suckers growing from the ground around it. Can those cherry tree suckers be grown into a new tree?

A: The white substance on the peonies would be powdery mildew. It is not very harmful to the plant. You can use a fungicide on it to control the spread of the disease. Also, make sure you cut off and remove the above ground growth that dies back in the fall to reduce the spores that overwinter for next year. The cherry suckers may not come up as the same species as you had planted and they may not be strong growing. Many of our fruit trees are grafted for a strong root system but desired traits from other trees. When suckers grow from the roots, you only get the type of tree that the main root system was and not the more desirable traits from the above ground portion of the plant. You can try it if you have room, but otherwise it would be best to start over from a new tree.

13. A caller put preen on his garden earlier this spring to stop the weeds. Now he is concerned if the plants he starts from seed this year will grow?

A: Unfortunately they will not grow where the preen is without extra care. You can either plant these plants from transplants or as seed in another location or in pots or you can till the bed to destroy the preen that is working as a barrier in the garden. Once you have gotten seeds to start growing in the garden, you can reapply the preen to reduce weeds later in the season.

14. A gentleman has holes around his house that are 1.5 inches in diameter and his tulip bulbs have been eaten off. What would cause these holes and how can the “critter” be managed?

A: This could be from either 13-lined ground squirrels or from voles. If it is voles, there would be runs in the lawn. Place a couple of snap-type mouse traps perpendicular to the runs in the lawn to manage the voles. If it is 13-lined ground squirrels, see this publication from UNL.

Yard and Garden: May 6, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for May 6, 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: Jennifer Morris, Forest Health Specialist for the Nebraska Forest Service

1. The first caller of the day has peach, plum, and apple trees that were recently planted. Should she use tree spikes for fertilizer for the trees and when should that be done?

A. Fertilizer for a tree is usually not necessary in Nebraska soils. Let nature take its course to naturally fertilize the tree. Fertilizer should only be used on trees, or any plant, as it is necessary. A plant can be damaged or even killed if they have too much of a particular nutrient, so it is best to do a soil test prior to applying any type of fertilizer to your plant.

2. A caller has grasshoppers in his lawn and has problems with large populations in the past, but he also has beehives nearby where he would want to spray to control the grasshoppers. Can he treat the grasshoppers and not harm the bees?

A. Insecticides that are commonly used as sprays for grasshopper control are very toxic to bees. You should only use insecticides for the grasshoppers in this situation for serious situations where chemical control is necessary. If sprays are warranted, you would want to do so on a calm day so the spray does not drift to the bees and mow the lawn first to reduce flower heads present that could get pesticides on them to get onto the foraging bees.

3. There is a caller who wants to plant some new apple trees. The trees he currently has continue to face problems with cedar-apple rust. What tree cultivars should he choose that will not have the problems with this disease?

A. There are many apple trees that are resistant to cedar-apple rust. When planting a new apple tree it is best to go in with a tree that is resistant to this disease because cedar trees are common in Nebraska, which is the alternate host. This allows most any apple or crabapple tree to be vulnerable to the disease. For resistant cultivars, see page 3 of this NebGuide on Cedar-apple rust by Amy Timmerman.

4. A caller wanted to know if they can use Roundup (or other glyphosate product) in their garden to kill pampas grass? Can it be wiped onto the stalks of the plant and not harm the peonies or raspberries that are growing with the pampas grass?

A. Yes, it can be used among raspberries and peonies, but it needs to be carefully applied so that you don’t get it on the leaves or other plant parts of the desirable plants. Painting the glyphosate product onto the leaves of the pampas grass will work into killing the grass and will keep it from getting onto the desirable plants. Grass-b-gone may work for it in the peonies and can be sprayed directly over the peonies and cause no harm to them, however this product should not be used in crops that are used for food or feed.

5. A caller has a mum growing on the east side of their house and it didn’t come back. Why is that?

A. Some of our mums are not as hardy as others. This may have been one of the lesser hardy mum plants. This mum was also moved in the fall so it may not have been ready for the winter after being moved or it could be planted in a more exposed location. If there is no green showing in the plant at this point, I would assume it is dead and it is time to replant.

6. A walk-in clientele asked what the orange pods were on her cedar tree? She also wanted to know if she should remove the cedar tree or if she can treat it?

A. This is the gall of the cedar-apple rust disease. In the rainy portion of the spring these show up to release the spores of the disease to move to apple trees. This disease is not harmful to the cedar tree so no treatment and definitely no removal of the tree is necessary.

7. A caller wanted to know how to start a new plant from the family tree peony plant.

A. Prune off a branch of the peony and place it into rooting hormone and then into soil or into a pot of gravel that is kept moist to start roots. Once roots have begun, the plant can be planted into the ground.

8. This caller has a 12-15 year old apple tree that has bark on the trunk that is splitting on the southwest side of the trunk. What would cause this and is it harmful to the tree? He also has a tree that has holes in the trunk that are in a row and about the size of a pencil. What is this from?

A. The holes in a line on the trunk of a tree would be from a yellow-bellied sapsucker, a type of woodpecker. This is not harmful to the tree and has no management strategy. As for the bark splitting on the apple tree, this sounds like sunscald. This is a disease that occurs in the winter when the cells in the bark freeze and thaw quickly and bursts the cells causing the split. There is no control for this and the trees will typically live a long, happy life after this occurs but the scar will remain for the life of the tree.

9. The final caller of the day has a windbreak with evergreens that were planted 9 years ago and they are too close together. What is the recommended spacing for trees in a windbreak?

A. 14-16 feet between trees is the average spacing requirement at this point. You need to maintain that distance so that when the trees are full sized they don’t overlap each other too much which can cause more disease problems.

 

Yard and Garden: April 8, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for April 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 Hosts: John Fech and Jonathan Larson, Nebraska Extension Educators for Douglas/Sarpy Extension

1. This caller has rye grass that is turning yellowish-brown after it was already greened up this spring. What is causing this brown coloration?

A. Take a look at the roots of the turf in these brown areas, see if they have dried out. Also, rye grass is more susceptible to winterkill than tall fescue or Kentucky bluegrass is and with these inconsistent temperatures and fluctuations we have been seeing this year, there is more chance that this turf was damaged from the winter conditions. Overseed the lawn now with a better suited turfgrass for Nebraska and delay crabgrass control until Memorial Day.

2. A caller has seed potatoes that he will be planting. How long should the sprout be on those potatoes?

A. This is not an issue, there is no need to worry about the length of the sprout. The issue with planting potatoes is to make sure that there is at least 1-2 eyes on each potato you plant.

3. Would it work to put a patio heater near a pear tree to protect it from damage from the freeze that is predicted for tonight?

A. This would not be feasible to keep the entire tree warm enough to protect it from a freeze occurrence. There is also a fire hazard issue I would be concerned with. For trees that are already blooming, there is really no way to stop the damage to the fruit formation that will come from freezing temperatures overnight.

4. This caller planted his potatoes on St. Patrick’s Day, as the old saying goes. However, they still have not emerged this spring. Is this a concern?

A. This year, St. Patrick’s Day may have been too early. The soils are still quite cold and wet which may cause concern for these potatoes. We would suggest digging up one of the potatoes to see if it is still viable or if it has started to rot in the ground.

5. The previous caller also asked whether a barrier spray with sevin around the garden might help reduce cucumber beetles in the garden?

A. This could work to catch some of the overwintering insects as they move into the garden. It may help to reduce the overall population in the garden.

6. A caller was wondering about the fate of their perennials and flowering shrubs with this freeze warning for tonight, mainly peonies, iris, and daylilies?

A. These plants are more adapted to Nebraska climates so they should be fine. This weather may cause them to lose some buds or cause some black coloration to the blossoms or leaves, but for the most part these will survive. If it is a concern for you, you may want to cover these plants with a sheet or blanket overnight tonight, but remove this during the day.

7. This caller has grass that is green but has large patches of yellow or straw coloration throughout the yard. What is causing this and how can it be fixed?

A. This sounds like a warm-season, grassy weed called nimblewill. This should be controlled in your lawn as it will take over. It can be sprayed with a glyphosate product, such as roundup, and then overseeded. This would need to be done in the fall so that you can spray the nimblewill when it is green and the fall is a good time to overseed. You can also purchase a product called Tenacity to control the nimblewill and harm the grass. Or you can call a lawncare company to control it for you.

8. A caller has apple trees near a cedar tree windbreak. Last year, the apple trees got rust disease. How can this be controlled? Should the cedar trees be removed?

A. Don’t cut down the cedar trees. The spores for cedar-apple rust can spread up to 2 miles and in Nebraska it is very difficult to get that far away from a cedar tree. It would be best to start with newer varieties of the apple trees that are resistant to cedar-apple rust. You can also spray your trees for cedar-apple rust. There is a very good Nebguide on Cedar Apple rust from Amy (Ziems) Timmerman found at: http://extensionpublications.unl.edu/assets/pdf/g1907.pdf

Twig Girdler Insect

Damage from Twig Girdler

9. This caller has 2 Linden trees in his front yard. With the windy days lately, many small twigs have blown out of the trees and it looks like an insect cut the branch off. What is causing this and what can he do about it?

A. This would be a small insect called a twig girdler. They will chew around the branches and make it fall off from a smooth cut. There is no insecticide necessary for this insect, it is best to just collect the branches and dispose of them.

2016-04-08 11.03.23

Greenbriar plant

10. A walk-in client was wanting an identification on a very thorny, green stemmed plant they have found growing up their trees and throughout their property.

A. This is a plant called greenbriar. It can be cut off repeatedly or in areas that are not in flower or vegetable gardens a brush killer product can be used.

11. A gentleman has a 5 year old azalea plant that isn’t blooming, what can he do to improve the blooms?

A. This is a plant that is inconsistent in our environment, we are on the edge of their growing zone. They also like more acidic soils and more protection than what we can often give them. It would be best to move it to a location of morning sun and afternoon shade. You can also add some fertilizer for acid loving plants, similar to what would be applied to blueberries or hydrangeas to give them a blue flower.

12. This caller has a black walnut trees in an old windbreak. Can they grow pampas grass or trumpet vines in close proximity to these black walnuts without detrimental effects?

A. Grasses are not usually affected by the juglone that is produced by the black walnut trees to deter other plants from growing near them. This juglone is produced to naturally reduce competition from the black walnuts with other plants. Trumpet vine should be tolerant because they are a tough plant.

 

Yard and Garden: May 8, 2015

Yard and Garden Green Logo

This is the Q&A for the Yard and Garden show for May 8, 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: Graham Herbst, Community Forester with the Nebraska Forest Service

1. This caller has pampas grass growing in her yard that last winter had problems with winterkill. What would be a good alternative ornamental grass she could plant?

A: Pampas grass had a lot of problems with winterkill last spring due to the dry, cold, windy winter conditions we faced in the winter of 2013-2014. Pampas grass is on the edge of its hardiness zone in Nebraska, but there are many other options for native grasses here. Maidenhair grass, or Miscanthus, is a great choice for a large native grass and it has many varieties to choose many different qualities. Big Bluestem and Little bluestem are great native choices, as well as switchgrass, sideoats grama, and many more. Ornamental grasses give us winter interest and habitat and food for wildlife during the winter months.

2. A caller had a sewer that was dug out and filled with soil. She then seeded new turfgrass on the area that has come up and is growing well. This spring the area sunk back down 6 inches. What can she do to level this area out?

A: You can remove the grass from that area, gathering 4-6 inches of soil and roots with it. Add soil to bring that back up to level with the surrounding lawn, and replace the grass piece back on top. Keep this grass well-watered until it becomes established, it will act like a piece of sod. The other option would be to back fill the location with soil and reseed the area with turf seed.

3. A caller has orange odd-looking structures hanging off of her cedar trees. What is this? Will it harm the tree?

Winter gall of Cedar-apple rust.

Winter gall of Cedar-apple rust.

A: These would be the galls from a disease called cedar-apple rust. This disease requires 2 hosts to complete its lifecycle, a cedar and an apple or something else in the Malus family such as a pear or crabapple. This disease overwinters on cedar trees as a hard, brown, odd-shaped structure on the branches and with spring rains they open up to look like orange, gelatinous, galls that are reminiscent of an orange octopus. This is when the spores are spreading to the apple trees. This disease causes no real damage to cedar trees, but on apple trees it causes lesions on the apples and leaf spots. Here is a NebGuide on Cedar-Apple Rust.

4. This caller has 3 apple trees and this winter one of them has not bloomed nor leafed out. Is the tree dead?

A: Check the tree for living tissue by scraping the bark off to expose green or brown tissue underneath. If it is green, it is still alive, if it is brown it is dead. Also check the branches for flexibility, if they bend they are still alive if the break they are dead. Give the tree a few more weeks to see if it comes out of it later this spring.

5. This caller has moles in their yard. How can they be controlled?

A: Moles can be controlled with traps. These traps will euthanize the mole in the hole to be left behind after control has been achieved. These have the best effect if the mound is pushed down 2-3 times prior to placing the trap in the hole, this will show if the tunnel is an active one before the trap is placed in it. Here is a guide from the Internet Center for Wildlife Damage Management on Mole Control.

6. This caller has voles in their yard. How can they be controlled?

A: Voles are controlled with snap traps that we typically use for mice. Place 2 traps in the run from the voles, or the area where the grass is damaged. Place the traps perpendicular to the runs and place them facing in different directions in the run. So, for a vole run that goes North to South, place one trap facing east and one facing west. Here is a guide from the Internet Center for Wildlife Damage Management on Vole Control.

7. This gentleman had used Scotts liquid turf builder on his lawn and it is not working to green up the lawn or to reduce the weeds found in his lawn. He also has a zoysiagrass lawn that is not growing as well in some portions of his lawn as it has in the past. What would be causing these problems and how can he improve these?

A: Broadleaf weeds are best controlled in the fall so it is best to apply a broadleaf weed killer, such as 2,4-D, 2 times in the fall, such as September 30 and October 15. Even in the spring, some control can be achieved, but they will require more than one application as they are tough weeds to kill. The zoysiagrass may have experienced some winterkill so it might be wise to take plugs from the area of the lawn where it is growing well and move them into areas of the lawn where it is not growing so well.

8. This caller has ash trees that are getting oval-shaped holes in them and ants on the trunk of the tree. Did the ants do this to the tree? How can it be managed?

A: These ants are probably carpenter ants. Carpenter ants do not harm your trees, they will just burrow into wood that has already begun to decay for some other reason. Carpenter ants on a tree do not require treatment. The holes are most likely due to native borers of the ash tree, such as red-headed ash tree borers or ash-lilac borer. These borers can be controlled with a trunk spray with chemicals such as sevin or eight or apply a soil drench with an imidacloprid product around the base of the trunk. This doesn’t sound like it is Emerald Ash Borer because the holes from EAB are D-shaped, not rounded or oval.

9. This caller has an ash tree and wants to know when he should treat it? He has heard that it takes up to 5 years for the systemic insecticides to move throughout the tree into the canopy, if this is true should he treat now.

A: Systemic insecticides take only a couple of weeks to move throughout the entire tree and they only last for 1 or 2 years depending on which chemical is used. It is best to wait until Emerald Ash Borer gets within 15 miles of the tree before treatment begins because treatments are costly, damaging to the tree, and not necessary until the borer gets closer. Trunk injections wound the tree and after repeated years of treatments it causes a great deal of stress to the tree, so there is no need to treat and harm the tree prior to when it is necessary.