Yard and Garden: July 28, 2017

Yard & Garden for blog, 2017

This is the Q&A for the Yard and Garden show for July 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 this will be the final episode from the show for 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: Kevin Christiansen and Evan Alderman, Agribusiness Instructors from Southeast Community College in Beatrice

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. This Survey will Close on August 18th.

1.The first caller of the day wants to know if they can still treat for bagworms that were missed with the first application?

A. If the bag is less than 1 inch in length, insecticide applications will still be effective. However, if the bags are larger than 1 inch in length, the insecticides will not work very well. Because this tree has already been sprayed this year and still has bags, I would remind everyone to ensure that they spray efficiently and according to the label, leaving areas untreated can lead to more resistance if those bagworms contacted a small concentration of the chemicals that didn’t kill them.

2. This caller called to ask me what was the best insecticide to spray for bagworms, since I left that out on the first call?

A. Tempo or Bt would be most effective. Bt is the safer alternative because it won’t harm a lot of pollinators as it just targets insects in the Lepidopteran family of insects which includes butterflies, skippers, and moths.

3. A caller has a redbud tree that blew over in a storm this spring. The roots of this tree have begun to grow some suckers. Can one of those suckers be cared for to grow into another redbud tree?

A. Yes, the suckers can be trained into a new tree. It would help the growth of the one you choose to grow if you leave the other suckers for a while as well. All of the suckers will provide energy and food to the roots, so leaving extras for a while will help. Once the main stem gets growing, you can remove the others to push the one upright.

This caller also wanted to know if he can prune his magnolia tree so he can mow under it?

A. As long as the branches are not more than half the size of the trunk and as long as you aren’t removing more than a quarter of the overall canopy the branches may be removed. The best time to prune a magnolia tree is just after it blooms in the spring, pruning now will cut off flower buds that have already developed for next spring. If the branches that would need to be removed for mowing are too large, it might be wise to change the turf to shade perennials such as carex, bleeding hearts, hostas, coral bells, jack in the pulpit, jacobs ladder, Helleborus or Lenten Rose and many other great shade plants.

4. When is the correct time to prune a burning bush?

A. Late fall after the leaves fall off would be best. It is always easier to see the branches and where problem areas are if you prune in the dormant season. Also, it will allow the plant to quickly seal up the wounds in the spring flush of growth. It is not advised to prune now because pruning woody plants after the beginning of August until when they are dormant can hurt the plant. This may cause the plant to push new growth that would be more sensitive to cool temperatures causing more dieback in the plant.

5. A caller wants to know how do you know when Butternut and Acorn squash are mature?

A. These are both winter squash varieties so the fingernail test will work just as it does with a pumpkin. When you think the winter squash is mature, push your fingernail into the rind of the fruits. If your fingernail pokes through the rind, the squash is not mature, if your fingernail does not puncture the rind, it is a mature fruit. Winter squash should have a hard rind.

6. This caller wants to know how to control windmill grass in his lawn?

A. For perennial grassy weeds such as windmill grass, there are two options for managment, either use a Glyphosate product, such as roundup, on the weed and then reseed or use a product containing Mesotrione product, such as Tenacity, on the weed and not harm the grass. The tenacity is more expensive but will not kill your grass so there will be no need to overseed.

This caller also wanted to know what would be digging up his grass?

A. This is likely due to either skunks or racoons digging the grass trying to get to grubs living in the soil. See the following NebGuides to learn how to manage these animals: Raccoons and Skunks Also, if this is due to grubs, apply a grub control next June to reduce the grub population in your lawn.

7. A caller has tomato hornworms in her garden. How can they be controlled? She also wanted to know what grubs come from and how to control them?

A. Sevin will work to control hornworms. However, the population is not usually terrible and the hornworms can be removed by hand and thrown into a bucket of soapy water for control. Grubs are the immature form of Japanese beetles, May/June Beetles, Masked Chaffer for the majority of species in Nebraska. They can be controlled in June with a grub control like the Merit products that contain Imidacloprid.

8. This caller has a 1.5 foot tall tri-colored beech that was planted in full sun this spring. About a month ago, the leaves turned brown. The caller is watering it 2-3 gallons of water every other day. What is wrong with the Beech tree?

A. Beech trees like to be in a more protected location, so this tree may be getting too much sun and too much heat. Because it is such a small tree, there is still time to replant the tree in a more protected and slightly shadier environment. Also, this small of a tree would not need this much water. When replanting it, keep it watered every other day with only about 1 gallon of water each time. After a few weeks in it’s permanent location, you can water with 1-2 gallons of water once a week and continue to back off on days between each watering as the tree grows larger. Remember, this small of a tree will not have a very large root system and it is as easy to overwater a tree as it is to underwater one.

9. How do you control moles in the lawn?

A. Moles are best controlled with a Harpoon trap that can be purchased at most hardware stores. For management tips, see this NebGuide on Moles

10. This caller has a hibiscus tree with a braided trunk that she thought would grow to zone 4, is this hibiscus going to be able to survive in Nebraska winters?

A. Unfortunately, it is highly unlikely that this is a hardy hibiscus that will survive winters in Nebraska. There is a hardy hibiscus that will survive our winters outdoors and those are suited up to zone 4, there is also a tropical hibiscus that is sold here as an indoor plant and will not survive our winter conditions outdoors. I would say that the tropical hibiscus would be the type purchased with a braided trunk. It can survive indoors during the winter months, so she can dig it up and put it into a pot to bring indoors for the winter.

2014-05-29 11.32.16

Clover in a lawn

This caller also wanted to know how to control clover?

A. Clover should be managed in the fall of the year. It will take multiple applications over multiple years to fully control clover in the lawn. Use 2,4-D or triclopyr products in the fall. It is best to apply these products around September 30th and again around the middle to the end of October.

The final question from this caller was if she should cut back her Virginia creeper plant that is turning brown?

A. Leave it alone and allow the plant to come out of the browning on its own. This is a common problem with Virginia creeper that is not terribly damaging to the plant.

11. How do you control anthracnose in tomato plants?

A. A copper fungicide can be used in a vegetable garden if necessary. However, often with home vegetable gardens it isn’t worth the time and money to spray our vegetable crops as the diseases usually only last for a short time and then fade when the temperatures change a little. However, it seems for this caller that the disease is a problem every year. For more information on controlling the disease and how to manage your vegetable gardens to avoid disease problems, visit this Nebguide on Leaf and Fruit Diseases of Tomatoes.

12. A caller has carpenter bees digging holes in her shed and wants to know how to control them?

A. Carpenter bees are a beneficial insect, except when they are burrowing into the wood framing of buildings reducing their structural integrity. They are best controlled with a dust formulation of sevin. Leave the dust in the holes a few days and then the holes can be filled in with a wood putty. For more information, see this guide from Lancaster County Extension on Carpenter Bees.

13. The final caller of the day wants to know how to control ragweed?

A. At this point, the plant is growing too strong to be killed with a herbicide. The best time to treat is in the spring before the plants have grown too large. At that time, they can be treated with 2,4-D. Now, the best control would be to dig or chop out the plants.

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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.