Yard and Garden: April 14, 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 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.

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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: May 27, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for May 27, 2016. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 5, 2016. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

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

1. The first question of the day came via email. A listener wanted to know how to control clover in their lawn?

A. Clover is best managed in the fall months when it is pulling nutrients from the leaves into the roots, it will take the chemical into the roots as well. Products with triclopyr work best, but 2,4-D will work as well. Make 2-3 applications in September and October for best control.

Mallow, Phil Westra, Co State Univ, Bugwood

Common Mallow photo by Phil Westra, Colorado State University, Bugwood.org

2. A walk-in question was for identification of a weed.

A. This weed is mallow. It is a difficult weed that will move throughout our gardens. It can be controlled with a careful application of Glyphosate (Roundup). Be careful not to spray any other plants with the glyphosate product.

3. A caller wanted to know when she can transplant daylilies and Iris?

A. The daylily could be transplanted now. It would be best to move these in the spring or in the fall, but daylilies are a tough plant and would be fine if moved now as long as they are kept well watered when it is hot because the root system isn’t developed at the new location yet. Iris would be best if transplanted in the fall.

4. A caller has earthworms making his lawn uneven. What can be done to control those?  This caller also wanted to know if he can water houseplants with water that goes through a water softener?

A. Earthworms are very beneficial to our soils as they reduce compaction and add organic matter back to our soils. The damage from them is only seen for a couple of weeks in the spring with rains. If you can deal with it for a short time, it is best to avoid treating for them. If you have to treat, Sevin insecticide does have some management capabilities for your lawn. As for watering the houseplants with water from a water softener, it is best to use water prior to the softener due to the increase of salts in the water.

5. This caller wants to know how far away from the house a shade plant should be planted? She also wants to know how she can manage grass in Iris’?

A. Spacing the tree from the house depends on the tree chosen and what the full size of that tree is. For many of the oak or maple shade trees, it is best to go 25-35 feet or farther from the house to ensure no problems develop as the tree grows. The grass in the Iris bed can be controlled with Grass-B-Gon.

6. A caller has a cherry tree that the top broke off but it is still attached to the main trunk. Can it be saved?

A. There is no way to re-attach a broken off branch. This branch will have to be removed. Because this is the only branch that is still producing leaves and cherries, the tree should be removed and replaced.

7. A caller has 2 rhubarb patches that were damaged badly by hail. The leaves look terrible. Should those leaves be removed or left on the plant?

A. If there are new leaves growing below the damaged leaves, the damaged leaves can be removed. However, if those damaged leaves are all that is alive on the plant right now, they should be left on the plant until new leaves begin to grow so that the plant can still grow and build nutrients for next spring.

8. A sample was brought in of a trumpet vine with many little insect all over the stem, leaves, and flowers. The plant has been sprayed with Sevin with no control. What can be done for this trumpet vine?

A. Sevin is not an effective method of control for aphids. In high populations you can use Eight or Malathion. Aphids are not very damaging to our plants and they are fairly short lived. Given time, predatory insects will move onto the aphids to control them without chemicals.

9. This caller was looking into planting apple trees and found there is a disease called cedar-apple rust. Is this a concerning disease here and what should be done to avoid problems with it?

A. Yes, cedar-apple rust is a damaging problem for apple trees. The spores can spread up to 2 miles, so it is best to plant a resistant apple tree cultivar. It is also good to look for cultivars that are resistant to apple scab. For choosing your cultivar, here is a publication from Purdue that lists common apple tree varieties and their disease susceptibility: Disease Susceptibility of Common Apple Cultivars

10. A sample was brought in of a tulip tree with leaves that are puckered and rolled downward. What would be the problem with this tree?

A. This tree has aphids on the underside of the leaves that are sucking the juices out of the leaves. Aphids are not terribly damaging to our plants and are fairly short lived. In high populations you can use Eight or Malathion.

11. Is there a dry granular weed killer for the lawn? When is the time to move gooseberries, iris, peonies, and rhubarb?

A. Fertilome is a good dry, granular weed killer. This is best applied early in the morning so it will stick to the leaf blades with the morning dew. Gooseberries should be moved after dormancy. Iris and peonies should be moved in the fall, typically in September when the tops begin to turn yellow. The rhubarb should be moved after they are dormant in the fall or early spring.

12. This caller has asparagus that has been planted in this location for many years and is now dying out. She fertilizes 2-3 times per year with a general fertilizer. What is causing this problem and can it be fixed? She also wants to know if she can use canning salt or Epsom salt in her garden? And, finally, she wants to know what to do for the aphids on her honeysuckle?

A. Asparagus will die out due to age. It would be beneficial to dig it up this fall after it goes dormant and divide the plants to replant as individual clumps. When replanting, sprinkle some bone meal in the hole to help with fertility. As for using epsom salt in the garden, this is not necessary. Epsom salt is magnesium sulfate which is in good supply in Nebraska soils. If nutrients are necessary in your garden, it is best to use a general purpose fertilizer. Canning salt can harm your plants and damage the soil. It is not a recommended practice to use any type of salt in your garden. As for the honeysuckle aphids, those should be controlled with Eight or Malathion. The aphids on honeysuckle can cause witches broom to the plant so they should be controlled.

13. Do raspberries and blackberries need to be grown on a trellis?

A. Yes, a trellis or an espalier would be a good way to grow them. Here is a good guide to growing raspberries and blackberries from Missouri Extension

14. Can red and black raspberries be planted together?

A. Don’t plant them within 20 feet of each other or they will cross pollinate and the fruits will not taste as good.

15. A caller has rhubarb that is shooting up stalks with seeds on them. What should be done with those?

A. Those seed stalks should be removed. Cut the stalk off at the ground. If left the plant will put energy into producing seed that should be stored for leaf and stalk production.

16. The last caller of the day has a mandevilla plant that is growing outdoors in a pot with a trellis. The leaves are now turning yellow and black. What is causing this and how can it be managed?

A. This is a moisture issue. The heavy rains this year are causing a leaf fungus to occur. A rose and flower systemic containing a fungicide can be applied to the plant to help reduce the disease.

Yard and Garden: May 20, 2016

Yard & Garden for blog

This is the Q&A for the Yard and Garden show for May 20, 2016. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am and it will run through August 5, 2016. It can also be found on kutt995.com for online listening. If you missed a show or just want to read through the questions, I have written them all in my blog and will continue to do so throughout the season.

Guest Host: Natalia Bjorklund, Dodge County Extension Educator

1. The first caller of the day has a problem getting grass to grow where he removed an asparagus patch. What can he do to get his grass to grow?

A. This is a situation where it could be a few things attributing to the problem. He was keeping the seedbed watered, by watering it 3 times a day for about 10 minutes each time he watered. Watering is important for seedlings, they need to be kept moist, so short, frequent waterings are necessary. This area could be compacted from years of asparagus growth, so it might be beneficial to till the area up prior to planting. The other issue he is facing this year is that it has been quite cool this spring. Mixing the cool temperatures with the moisture, it might be too cold for germination. It is suggested to try again with new seed after tilling the soil up and a soil test may be necessary after that to ensure the soil is ok after so many years with asparagus on it.

2. A caller has a newly planted red maple tree with holes in the leaves. They do have black spots on the leaves as well. The new growth seems to not be affected like the original leaves. What would be the problem? Is this an insect issue?

A. This could be a leaf spot fungus with black spots on the leaves that have died out. When a leaf spot occurs on tree leaves, often the dead area will fall out of the leaf. Leaf spots are not very damaging to our plants. Since the new growth seems ok, it shouldn’t be treated and the tree will grow out of it and be fine.

3. A gentleman has evergreen trees that have brown tips on the branches. Is this being seen in other locations?

A. This is probably just an environmental problem on the branches that should fade in time. It is being seen in other trees, especially in white pines which are facing problems with winterkill, a common issue where the tips of needles on white pines turn brown after strong winter winds. It is not a concerning issue.

4. This caller wants to know how to control weeds growing around her containers that she is growing tomatoes and strawberries in? Can any chemicals be used that close to these crops?

A. Tomato plants are especially sensitive to chemical drift especially from 2,4-D which is a common herbicide used for lawn weeds. To be safest and not have problems from the 2,4-D being that close to the tomatoes and strawberries, mechanical control would be the safest option. mulching around the containers will help to keep the weeds from coming back.

5. A caller has blackberry leaves that are turning orange and then back to green. What would be causing this?

A. This sounds like the plant is having an issue with rust. The rust covered leaves then are falling off and new, uninfected leaves, are reappearing. Remove all infected leaves as soon as you notice the fungal spores. Rust will not kill the plant, it may show up on the berries slightly. Chemical controls are not necessary for a home gardener.

6. A gentleman planted fescue grass seed this spring and it seems to be a thin stand. Should it be overseeded? Will it fill in?

A. Fescue does not tiller out like bluegrass does. So it should be overseeded to help fill in the gaps in the turf.

7. What chemical can you use for tree stumps to help keep them from growing back?

A. 2,4-D is a good option to apply to a newly cut stump or drill into the stump and pour it into the holes. It can be mixed with Roundup to help as well. Do not use Tordon in a landscape setting as this would be a direct violation of the law.

8. This caller transplanted peonies a few years ago and they haven’t bloomed since they were moved. What is wrong with them?

A. If peonies are planted or transplanted too deeply in the soil they will not bloom. Dig the plants up and reposition them higher in the soil profile. It can be done now or in the fall, the fall would be the preferred time of the year.

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.

9. An email listener wanted to know if fertilizer changes composition over time?

A. Yes, it can break down and become less effective. If fertilizers are stored where they freeze and thaw continually or get moisture into them, they will not work as well as they originally did.

10. A caller has a windbreak that is dying. What are some good tree choices to replace the windbreak with?

A. Cedars, black hills spruce, Colorado blue spruce, Douglas fir, concolor fir, white pine, ponderosa pine, or Jack pine would all be good replacements. Make your windbreak out of a diverse selection of these trees. Don’t go with a windbreak of one tree species.

11. This caller has a peace lily that the leaves turn brown and then die back. It continues to go through this process. It has been repotted but is still exhibiting the damage. What is it and how can it be improved?

A. This could be due to overfertilization or too much salt content in the water. Try using distilled water for a while. It will flush out the salt content from previous water over time. Eliminate the use of any fertilization. It is a common problem in peace lily plants and they should be fine.

12. What chemicals can be used for bagworms and when should they be sprayed?

A. Bagworms are typically active in the third week of June and this would be the best time for spraying. The emergence of the bagworms is weather dependent and it can range from the middle of May to late July. Average years it is the third week of June for the timing of sprays. It is best to just watch your tree and spray when the new bags are 1/2-1 inch in length. You can treat them with general insecticides such as Sevin, Eight, Bt, or Tempo.

fern leaf peony, Lee Ruk Flickr

Photo of fern leaf peony from Lee Ruk via Flickr Creative Commons License

13. The last caller of the day wants to find a fern leaf peony. It seems to be hard to find. Where could she find this plant to purchase?

A. It should be fairly easy to find at a local nursery. Many of the box stores probably will not have this unique and interesting plant.