Tree Galls

Spring is a great time of year. We can enjoy spending time outdoors with our friends and family and enjoy the views throughout our landscape. However, that view is sometimes interrupted by weird formations that show up on our tree leaves which are called galls. The good thing about galls is that they are not harmful to our trees, they are just displeasing to the eye.

Galls are commonly seen on many of our tree species. A gall is a deformation on the plant usually caused by an insect but they can be caused by fungi, bacteria, and other organisms. Galls can form on the leaves or on the branches but it is developed as a result of the feeding activity of the insect or mite that then lives inside the gall.

One of the most common types of galls is the Hackberry nipple gall which forms on the underside of the leaf of hackberry trees. This is a very common gall, in fact, it occurs so often that it can almost be used as an identification characteristic of the Hackberry tree. In the fall, the psyllids, or tiny black insects, come out of these galls to mate and often become a nuisance insect in our homes. They are so small that they can get through our window screens and enter our homes to fly around and pester our families.

HackberryNippleGall, S. Browning

Photo of Hackberry Nipple Gall by Sarah Browning, Lancaster County Extension

Another common gall that we are seeing right now is the bladder gall on Maples. This particular gall is caused by a mite. The signs we see from this insect feeding on our trees would be small, bright pink bumps on the top side of the leaves.

maple bladder gall

Photo of Maple Bladder Gall

Oaks also get a couple of galls. There is a leaf gall that is fairly common among oak trees called the oak apple gall which is a large, round, tan-colored gall on the leaves. It is a growth filled with a spongy center and contains one wasp larvae in the middle. Bur oaks commonly get a bullet gall which grows all over the branches of bur oak trees. These galls appear as marble-sized, tan, hard structures attached to the branches of the tree. The bullet gall, which is caused by a parasitic wasp, is generally not harmful to the tree, but if the infestation gets very high, it can cause branch dieback.

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Oak Bullet Gall

Cottonwoods get a petiole-leaf gall. This gall is caused by an aphid and is a puffy ball located at the base of the leaf where it meets the petiole, or the stem-like structure that attaches the leaf to the branch of the tree. The petiole-leaf gall will contain many small aphids later in the season that will not harm the tree.

These insect galls are generally not harmful to the tree. They mainly cause aesthetic damage and don’t affect the health or longevity of the tree. There is no way to control the gall insects once the galls appear on the tree and prevention is difficult and not recommended.

Part of the information for this article came from an article written by Mary Jane Frogge, a UNL Extension Associate from Lancaster County Extension.

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.

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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.

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.

 

Peach Leaf Curl

Lately, I have had quite a few community members come into the office with a problem on their peach tree. The leaves look funny and have a pinkish color to them. The same problem is being seen throughout the area and unfortunately, there is nothing we can do about it, at least not for this year. The problem many people are dealing with is Peach Leaf Curl.

Peach leaf curl is caused by the fungus Taphrina deformans. This fungal disease is one of the most common diseases in the home orchard and can affect the blossoms, fruit, leaves, and shoots of peaches and nectarines. (Cherries have a similar leaf curl diseases caused by T. cerasi.) Peach leaf curl is more severe following cool, wet springs; temperatures between 50 and 70 degrees F are ideal for infection, which is why we are seeing it so often this year.

Peach Leaf Curl, Paul Bachi, Univ of Kentucky R and E Center, Bugwood

Photo of Peach Leaf Curl is from Paul Bachi, University of Kentucky Research and Education Center, Bugwood.org

The primary symptom is a thickened, puckered area on leaves which will turn yellow to red or purple with the loss of chlorophyll. These leaves may prematurely drop, weakening the tree and making it more susceptible to other diseases, pests, and cold injury. The disease can also result in reduced fruit set, size, and quality.

A single fungicide spray applied while trees are still dormant (just prior to bud swell), thoroughly covering all branches, shoots, and buds will control peach leaf curl. Effective controls include Bravo, Ziram, and copper compounds.

At this time of year, most infection has already occurred, and fungicide sprays are relatively ineffective. Fruit on defoliated trees should be thinned to reduce stress and improve tree survival.

This information on Peach Leaf Curl came from Connie Fisk, a fruit tree expert for Nebraska Extension located in Cass County. Read more from Connie on her blog, Food Adventures with Connie

Another thing to think about this time of year, is what type of fruit tree to plant if you are thinking about planting new trees. You need to decide what type of fruit you prefer to grow, what you will be using your fruit for, and if the tree is self-fruitful or if you need to plant a pollinator tree nearby. It is also best to plant fruit trees that are resistant to the common diseases found in our fruit trees. For apple trees, select a tree that is resistant to cedar-apple rust and apple scab. For peach trees, choose a tree that is resistant to bacterial spot. For pear trees, choose one that is resistant to Fire Blight.

apples-A. Henneman flickr

Flickr image courtesy of Alice Henneman per CC license

For Apple trees, some good choices include Redfree, Johnafree, or Liberty. For Pear varieties, look at Moonglow, Luscious, Lincoln, Magness, or Seckel. For Peaches, choose Reliance, Red Haven, Contender, or Madison.

There are many other great choices for fruit tree varieties to use. Nebraska Extension released a NebGuide in July of 2016 called ‘Fruit Tree Cultivars for Nebraska’. It is a good guide that helps you to find the fruit tree variety or varieties you need for your fruiting wishes.

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.

Tree Selection and Pruning

2014-06-12 16.10.39

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

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

2014-10-06 15.27.18

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

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

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

pruning tools-K. Todd

Photo courtesy of Kim Todd, UNL Department of Agronomy and Horticulture

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

Yard and Garden: April 14, 2017

Yard & Garden for blog, 2017

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

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

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

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

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

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

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

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

2012-05-25 12.04.38

Bare lawn in need of overseeding.

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

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

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

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

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

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

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

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

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

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

Curly Dock, Steve Dewey, Utah State Univ, Bugwood

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Yard and Garden: 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.

Which Herbicide to use…

2014-04-26 10.02.21

Photo by Nic Colgrove

Spring is coming. And with the onset of warm weather and more spring rains, comes many different lawn weeds. Each year we tend to find new herbicides in the garden center of our favorite stores. However, when dealing with pesticides, it is very important to know what you are purchasing and how to correctly use it so as to not harm the environment, pollinators, and beneficial plants.

One of the things we all need to remember when using pesticides is to use the right product for the job and to know what you are using. To use the trade name Roundup isn’t going to be enough anymore. There are a lot of new Roundup brand products that each have a different combination of chemicals.

Roundup 365 is a new product from Scotts that contains both glyphosate, which is the active ingredient in the general Roundup product, as well as Imazapic. Imazapic is a selective herbicide used to control annual and perennial grasses as well as some broadleaf weeds. It has a trait that allows it to last longer in the soil than a regular glyphosate product which is essentially deactivated when it hits the soil. In accordance with the label, Roundup 365 should only be used in cracks and crevices in sidewalks, driveways, walkways, and tennis courts, amongst patios and paths, along fences, foundations, curbs, retaining walls, and landscape borders, and in gravel areas and parking areas. It is not to be used in areas where planting or seeding will occur for the next year or in the root zone of plants or in any other garden setting where desired plants are. Also, be careful when applying this to fenced areas as it should not be applied where there are desired plants on the other side of the fence that could be damaged with the application of this product.

Roundup for Lawns is another new product made by Scotts that actually contains no glyphosate. Roundup for Lawns contains MCPA, Quinclorac, Dicamba, and Sulfentrazone. MCPA is a herbicide similar to 2,4-D for broadleaf weeds. Quinclorac is a post-emergent crabgrass and annual grass herbicide. Sulfentrazone is the active ingredient found in Sedgehammer that is often used on yellow nutsedge. Dicamba is one of the 3 active ingredients in Trimec that is used for broadleaf weed control in a lawn. This product can be used over an established lawn because it has no ingredients that will kill established turfgrass.

2015-06-25 10.19.56

*Reference to commercial products or trade names is made with the understanding that no discrimination is intended of those not mentioned and no endorsement by University of Nebraska–Lincoln Extension is implied for those mentioned.

Dicamba is a pesticide that we should be very careful with, as well as any pesticide that contains dicamba which includes Roundup for Lawns and Trimec. Dicamba can turn into a gas and move to non-target plants as a vapor in temperatures of 85 degrees and above. This volatilization can occur for the day and even a couple of days after application. So Dicamba products shouldn’t be used in the summer months. Also, be very careful with Dicamba products in your lawn around trees and shrubs. This product can cause injury to these plants when it moves through the soil and comes into contact with the roots. Limit use of this product to no more than twice per growing season around tree roots to avoid injury.

Each of these Roundup products are labeled for different uses. So, make sure that you always read and follow the label instructions provided with the product to ensure that you are using the product correctly and so that you don’t harm the environment or any non-target plants. Always keep the label and product instructions with the product so you will always know how and where to properly apply it.

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

Yard and Garden: March 31, 2017

Yard & Garden for blog, 2017

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

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

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

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

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

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

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

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

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

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

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

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

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

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

buffalobur, Howard F Schwartz, Colorado State Univ, Bugwood

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

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

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

8. When should asparagus be fertilized?

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

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

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

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

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

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

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

3-step pruning cut

Proper pruning cut, University of Missouri Extension

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

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

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

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

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

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

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

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

henbit, steve dewey, Utah State Univ, Bugwood

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

16. What can be done to manage henbit?

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

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

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

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

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