Yard and Garden: June 1, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for June 1, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 3, 2018. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

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

1.The first caller of the show wants to know how to control grassy weeds in peonies and in asparagus?

A. In the peony plants, you can spray Grass-b-Gon or another product containing fluazifop-p-butyl to kill perennial and annual grassy weeds. However, this product cannot be used in asparagus. For weed management in asparagus, it is best to use mulch through the season to keep the weeds down. Roundup, or glyphosate, can be sprayed over top of the asparagus in the beginning of the season before the asparagus begins to grow, after harvest once all the stalks have been cut off below the ground level, and at the end of the season after removing the ferns and no green of the asparagus is showing above ground. Preen that is labeled for use in asparagus can be used throughout the season as well to stop the germination of new, annual weeds.

2. This caller has ants on their potatoes and radish with a great deal of damage. What can be done to stop the ants from damaging these plants more?

A. It is likely that the problem is not due to the ants, they are likely there as a secondary issue and they are not eating the potatoes and radish. Grubs will feed on the tubers and other underground structures. They do not typically affect tomato roots or the roots of the other above-ground growing plants. There are no products labeled for grub control in a home vegetable garden. If the grubs are becoming a problem, move the garden next year and treat the area without the vegetables on that area for a year. Treat for grubs in the lawn around the garden to help reduce the population.

3. A caller has had poor pollination in cucumbers in past years. What can he do this year to ensure he has better cucumber production?

A. If there aren’t many bees or butterflies around the garden, it could be low pollination. Try to attract pollinators through additional pollinator garden areas. You can also hand-pollinate these plants with a cotton swab, touching many flowers throughout the plant with the same cotton swab to transfer the pollen throughout.

4. This caller purchased burning bushes in containers and then left for 4 days before getting them planted. Now, the leaves are brown and crispy, are these plants dead or will they pull through?

A. If branches are brittle and break rather than bend, they are likely dead and will not regrow from that. In the late May time frame, it is going to be difficult to keep a newly planted shrub watered well enough in this heat and drought, this will be even more difficult if the plant is not placed into the ground right away. Containerized plants would need to be watered at least once a day now that it is so hot.

5. A caller planted 2 fruit trees and a red maple that they received through a mail-order service. The fruit trees are doing fine, but the maple has not leafed out and is not growing well at all. What happened? Will the tree come through?

A. Sometimes during transportation, bare root trees will dry out and they are not able to recover from that. It is best to purchase your plants locally to ensure this does not happen.

Carpenter Bee, J. Kalisch

Carpenter Bee Photo from Jim Kalisch, UNL Entomologist

6. How do you control carpenter bees?

A. Carpenter bees are a good pollinator insect and will not sting you. If they are doing damage to the structure of a building, you can fill the holes with some caulk or putty. If you would like to, you can inject sevin dust into the holes before sealing the holes to kill the bees. For more information here is a guide from Lancaster County Extension on Carpenter Bees.

7. This caller has Siberian elms growing within a well-established windbreak that are dropping yellow leaves. What is wrong with the trees?

A. It is likely that the trees turning yellow are hackberry trees growing in the windbreak rather than the elm trees. Hackberry trees have recently been dropping leaves like they do in the fall. They tend to do this in the late spring if the weather becomes unfavorable to their growth. They will drop their leaves and then push new regrowth. This is likely due to the quick change to hot/dry this summer.

8. A caller just planted rose bushes and oak leaf hydrangea plants in full sun with a rock mulch. Now the roses have holes in the leaves and the hydrangea plants are getting rush spots. What is wrong with these plants?

A. After a picture was emailed, it was determined that the roses had rose slug damage. Rose slugs are actually the immature form of sawflies that feed on roses this time of year causing brown spots in the leaves and holes. Rose slugs resemble a caterpillar that is translucent green with a brown head and they are found on the underside of the leaf. They are not very detrimental and do not need to be controlled. They are a short-term problem. Also, it is difficult to control sawfly larvae and not harm pollinators in the flowers of the rose. The hydrangeas are exhibiting problems with heat due to being planted in full sun with a rock mulch. Make sure to keep them well-watered to avoid more problems.

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Creeping Charlie in a lawn

9. This caller has a mint smelling weed growing in his yard. What is it and how do you manage it?

A. This would be Creeping Charlie, also called ground ivy. This weed can be difficult to control, but it is best managed in the fall. Many broadleaf herbicides will work for creeping Charlie, including 2,4-D, trimec, tenacity, or triclopyr. It is best to apply one of these chemicals 2 or 3 times in the fall. One application can be made around September 15th with a second application around October 15th. It will take multiple years of this management plan to fully rid the yard of ground ivy.

10. A caller has zucchini leaves that are crisp and curled up rather than smooth like normal growth. What is wrong with the plant?

A. After discussion with the caller, it was determined that she should spread her watering out more. Our vegetable gardens need about 1 inch of water per week, but this should be spread out over 2 or 3 times per week if rain is not providing that water. She also sent a photo to Nicole, where it was determined that this might be due to herbicide drift from a broadleaf herbicide applied nearby. In the heat and humidity we are dealing with currently, it is best to not use broadleaf herbicides anymore now until the fall of this year to avoid volatilization of the chemicals where they turn into a gas and move around to non-target plants.

11. How much water does a lawn need? How do you know how much water you are applying? Should you water in the afternoon to cool the grass off or is that a myth?

A. A lawn need 1-1.5 inches of water per week. If you are not getting that naturally, it is best to apply 1/3-1/2 of an inch 3 times per week to keep the lawn healthy. You can do an audit of your system to know how much you are applying each time you water. Simply place tuna cans or some type of catch device throughout the lawn to catch the irrigation as it runs to determine how much is being applied each time. As for syringing the lawn, no it doesn’t really help the lawn cool off. Lawns transpire as a natural way to cool themselves, and syringing only cools the lawn a few degrees for a few minutes. For more information on syringing, here is a good Turf iNfo article from Bill Kreuser at the UNL Turfgrass Department.

12. This caller has something that is digging large holes in the yard. What would be causing this and how can the damage be controlled?

A. This could be due to a skunk digging up the grass looking for white grubs. Treat the lawn for grubs in the middle to late part of June to help reduce the attractant for the skunks. For more on skunks and how to control them, here is a guide from UNL Wildlife.

13. A caller is looking for a good plant to use to grow up a windmill. Would a vining hydrangea be a good choice to grow on the windmill that is in full sun?

A. No, hydrangea plants don’t grow well in full sun. Honeysuckle would be a good choice for this location. If you can keep the roots a bit shaded, clematis would be another great choice.

14. The final caller of the day wanted to know how long tulips can live?

A. Some of the newer varieties may not live as long as some of the old types. However most will grow for many years.

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Yard and Garden: April 27, 2018

Y&G Blog Photo, 2018

This is the Q&A for the Yard and Garden show for April 27, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 3, 2018. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Dick Campbell, Owner of Campbell’s Nursery in Lincoln

1.The first caller of the show wants to plant hydrangea’s on the south side of a porch. Will they grow well in that location?

A. Most hydrangeas like part shade and wouldn’t grow as well in a location of south sun. However, ‘Limelight’ and ‘Little Lime’ would be good selections for full sun. The ‘Little Lime’ hydrangea will only grow up to 3 feet tall while ‘Limelight’ will grow up to 6-8 feet tall.

2. A walk-in listener has a 12 year old boxwood that is turning whitish-brown throughout most of the plant. What, if anything, can be done to save the plant?

A. This could be boxwood blight or winter desiccation. The fact that the boxwoods started to turn brown in the summer makes it less likely that it is winter desiccation. Also, the plant is brown and dead throughout the majority of the center of the plant, where winter desiccation typically only shows up on the top and outer sides where wind directly hits the plant. Either way, too much of the shrub has become dead branches so it should be removed. Boxwoods can be replanted into the area where the blight was a problem previously with no harm to the new plants.

3. A caller has Dwarf Alberta Spruce trees that have brown spots on them. Last summer he sprayed the plants with a copper fungicide, but should something else be done to them?

A. Dwarf Alberta spruce is prone to problems with spider mites in the summer months. If it is spider mites, when they start becoming active again, they can be killed with a strong spray of water. The bigger problem is that this is a very slow growing tree and it may never fill in again where the dead areas have appeared in the trees.

4. This caller has pecan trees that the top has died back on them over the winter. Can he prune it out and maintain the trees?

A. Give the trees time to leaf out this summer to know for sure where the dieback is found through the tree. With the cooler spring this year, many of our plants are slow to come out of their dormancy. Wait until the tree is fully out of dormancy before pruning it. After it has leafed out fully, cut the dead areas out, but cut back to a bud at the top of the tree so that you can use that bud to reestablish a new leader.

5. A caller has underground irrigation and planted a new lawn via seed and some via sod last fall. What type of watering schedule should he be on now?

A. Because this lawn was established last fall, you would not need to keep up the same schedule as last fall, the roots should be established now. Wait to start up the irrigation after spring rains begin. 1 inch of water per week would be the recommendation now, that is what established lawns require, so it would be the same for this lawn. Most often, we give our lawns 1 inch of water per week through 3 irrigation cycles of 1/3 inch each time. Make sure you check your irrigation rates when you first turn your system on for the year.

6. This caller has a 25-30 foot tall red oak in his yard. Every year for the past 2-3 years, the leaves come out cupped and small and stay that way through the entire growing season. What is wrong with his tree? He has other oaks in his yard that don’t look like this.

A. The cupping leaves sounds similar to herbicide drift. Typically, though, the trees will grow more leaves later in the season that are not cupped. If this was herbicide damage, it is likely that all the oaks in the yard would have this problem, but it still could be herbicide damage. It could also be from a small mite or other insect that is sucking the juices out of the leaves as they emerge. It would be best to bring a sample to the show or to Nicole to take to the lab for further testing. If it is herbicide damage, multiple years with damage to a tree can start to stress and kill a tree.

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Henbit blooming

7. A caller has a zoysiagrass lawn that is full of henbit for the first time this year. Is there anything to do for that now?

A. Henbit is blooming for the year now, which means it is already setting seed for more henbit to grow there next year. Henbit is a winter annual that germinates in the fall, goes dormant over the winter, then comes up in the spring and flowers and produces seed before it dies with the summer warmth. Because it is getting so late in the year and the seed is already there, there is no reason to treat for henbit now. It will die soon, once the temperatures warm up. next fall, treat with a 2,4-D product in October or November to kill it as it first germinates in the fall.

8. How do you control Creeping Charlie in the lawn?

A. Creeping Charlie is best controlled in the fall months with a 2,4-D product or a product containing Triclopyr. It is best to do 2 applications in the fall, one in the middle of September and another at the end of October. The caller was going to overseed, so it was advised to overseed this spring and then treat the Creeping Charlie in the fall for best control. It will take multiple years of treatments to fully reduce or eradicate Creeping Charlie, but spraying in the fall will start knocking it back.

9. This caller has Sod that was installed last November and now some cracks have shown up between the sections of the turf. What can be done to fix that?

A. Add some soil to those areas of bare ground and then reseed those areas. Cover the new seed with peat moss while it establishes to keep it moist.

10. A caller wants to know how to plant strawberries and what varieties are good choices?

A. Sarah Browning, Lancaster County Extension, has written a good article on Planting a Strawberry Bed

11. The last caller of the day wanted to know if they should till their garden before planting and when to prune her hydrangea shrub?

A. If the soil is loose and has a good level of nutrients, you wouldn’t have to till it first. It might be a good idea to till it first to loosen it up and to add nutrients back into the soil for better production.

As for the hydrangea, this is a late summer blooming hydrangea, so it can be pruned now and still produce flower blooms for August or September this year. It can be pruned back to the ground if it is overgrown. If it is not too overgrown, the largest canes can just be cut out of the plant, leaving the more productive, smaller canes in the plant to grow.

Dandelion Control Should be Done Now

2014-04-26 10.02.21

Photo by Nic Colgrove

Weeds in the lawn will drive us crazy through the whole summer, but don’t forget about them yet. Fall is the best time to treat for broadleaf weeds, even though we don’t notice them as much now because they are done blooming for the year.

Perennial broadleaf weeds including dandelions, creeping Charlie or ground ivy, and clover are best controlled in the fall once the weeds have begun their preparations for winter. In the fall months, these perennial weeds will move sugars that they use for energy from the above ground portions of the plant down into the roots to store them for next spring. If they are sprayed during this phase of their lifecycle, they are more likely to take that herbicide down into the roots and kill the plants rather than just burn the tops off.

The cooler temperatures in the fall are better for turf and ornamental plants due to a reduction in volatilization. In the warm summer days, the herbicides we typically use on broadleaf weeds can turn into a gas and move to non-target plants, causing damage and in some cases even death. With the cooler temperatures, this is not a big concern because the common chemicals we use, such as 2,4-D and Dicamba, do not volatilize at temperatures below 80 degrees. Wind drift is still a concern, so always be sure to apply herbicides on days with little to no wind.

The fall is not the time to worry about or treat for summer annual weeds such as crabgrass. Those plants that are still alive will die with the first frost and the seed will not germinate until next spring when the weather warms back up again. However, you can treat now for winter annual weeds such as henbit, speedwell, and little barley. Once they have germinated this fall you can use a 2,4-D product, which can be achieved with a late October and into early November application for dandelions.

Remember, all of these chemical controls are pesticides and therefore need to be carefully considered and applied according to the label. Any material used to maintain a landscape, including fertilizer, sand, or pesticides, can end up in the storm sewer and lead to pollution of lakes, rivers, and streams. In the same manner, even our grass clippings and leaves can pollute our water supply. There are ways to manage our landscapes while reducing water pollution. The following will help when managing our lawns this fall:

  1. Any fertilizers, pesticides, and grass clippings should be swept back onto the landscape. Using a leaf blower will work as well. The idea is to keep these items on the greenscape rather than on the hardscape that leads easily to the storm sewer. Raking up leaves in the fall will also help reduce the amount of leaf debris that ends up in the water.
  2. Check your sprayers before using to ensure they are properly calibrated and the nozzles are not clogged.
  3. Compacted soils and thin turf do not allow fertilizers and pesticides to infiltrate the soil surface. Aerate and add organic matter to improve the composition of the soil to ensure these products do not run off of hard, compacted soils. Reseed bare areas of the lawn to catch lawn products.
  4. Thatch layers in the lawn can become a natural barrier to prevent infiltration. Aerate the lawn to reduce the thatch layer to allow lawn products to infiltrate their intended areas.

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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.