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.

Yard and Garden: April 15, 2016

Yard & Garden for blogThis is the Q&A for the Yard and Garden show for April 15, 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: Jeff Culbertson, UNL Landscape Services

1. The first caller of the day has asparagus that she planted last Spring. What needs to be done with the plant now?

A. Light harvest can be done the second growing season and then full harvesting can begin the third season. Mulch it now to keep weeds down, herbicide sprays are not able to be safely used too close to growing asparagus. Cut the plants back in the fall after they have grown well all season. Fertilizer can be applied now or in the fall.

2. How do you control moles in the lawn? How do you control grubs in the lawn?

A. For mole control, see this guide from the Internet Center for Wildlife Damage Management: http://icwdm.org/handbook/mammals/mam_d51.pdf Make sure that you have found an active run area before implementing any traps by stomping the mounds down for a couple of days prior to setting the trap. For grub control, the best option is to apply a product containing Imidacloprid around the third week of June.

3. This caller from the Southern part of the United States said that it is difficult to grow asparagus in the south. Is this due to the lack of dormancy in the south compared to what we have in Nebraska?

A. Yes, asparagus would need to have a rest period that occurs during our winter in Nebraska. However, the roots are also prone to root rot problems, so it might be that your soil could be too high of clay that isn’t allowing the asparagus roots to dry out enough.

4. Another caller has Iris that they have sprayed with Sevin for iris borers that are always a problem. Is this the best product and when should she be applying it? Also, she applied lime to the plants and now they are a lime green color instead of the deep green they are supposed to be. What is causing this discoloration?

A. Lime is used for acidic soils to raise the pH. In Nebraska, most of our soils are heavy clay and therefore already have a high pH. The addition of the lime to the soils in this case is causing chlorosis on these iris plants. It will work through over time, but for a couple of years the iris may look a little tired. The Iris borers have not shown up yet, but a treatment with an imidacloprid, permethrin, or bifenthrin soon or just as the larvae come out would be ideal for control.

5. This caller is wondering what the timing is for fertilizer with crabgrass pre-emergent herbicide? He is also wondering how to control bindweed in bromegrass?

A. Anytime in the next week or 2 would be ideal for fertilizer and crabgrass pre-emergent use this year. The soil temperatures are at 54.9 degrees Fahrenheit for the 7 day average. Crabgrass will germinate at temperatures between 55-60 degrees Fahrenheit, so you can begin applying your control methods anytime now until the end of the month for best control. The bindweed can be controlled with trimec  if used 2-3 times per summer. Keep the bindweed mowed to prevent flowering from occurring to reduce the amount of seed left in the grass.

6. A caller has cedar trees that were recently pruned from the bottom up. What would be a good grass to grow under these trees?

A. A fescue grass would grow well in this shady environment. Also, a nice groundcover such as purple leaf wintercreeper would be a good alternative to grass to reduce mowing under the tree and to grow better in the shade of the tree.

7. This caller from Hickman has a cherry tree. Every year they mow off many “little trees” that grow up and around the cherry tree. Is there anything else to do to reduce the occurrence of these trees?

A. Suckering occurs with many different tree species. These suckers may be growing off of the roots of the main tree so chemicals should not be used or else you may end up killing the desired tree as well. Cutting them off or mowing over them before they grow too large would be the best options for control.

8. This caller has fruit trees. He is wondering if a product called “fruit tree drench” for insects would be ok?

A. Not knowing the active ingredients in this product makes it hard to answer the question. Systemic insecticides are not usually safe for use in plants that are edible because a systemic insecticide will move throughout the entire plant, including into the edible parts. It is suggested to do more research on the safety of the product or to move to a spray type of insecticide that is not systemic to reduce the health hazards that may be a problem with systemic insecticides.

9. Another caller has an apple tree that is 7-8 years old. The last 3 years it has produced nice apples but they are rotten inside. Now there are not many apples that are not rotten on the inside. What can be done for this?

A. Sanitation is going to be key for controlling this disease, known as black rot of apples. A orchard fruit tree spray program can be used to minimize the damage as well. Pruning may need to be done to remove any branches that are dead or diseased.

10. A caller wanted to start a new strawberry patch. How far should the plants be spaced in the garden and what should be done to the soil for improvements?

A. Till in compost and topsoil for increased organic matter and reducing compaction in the soil. Space the plants 1 foot apart.

11. This caller has a maple tree that is not budding out and has not yet lost the leaves from last spring. Will it survive?

A. Some maples, such as the sugar maples, have not yet leafed out for this spring. Use the fingernail test to scratch the bark lightly on smaller branches to see if there is green underneath the bark. Green under the bark means the tree is still alive and waiting to come out of winter dormancy, brown under the bark means it died over the winter.

12. A caller wants to know about the “spray on grass”. Will it work for overseeding?

A. Should work ok, but check with the types of grass seed included in these cans. Many of these mixes have perennial rye which doesn’t last long in Nebraska environments. Also, check for the amount of weed seed found in the mixture.

13. Is it too late to thin Iris plants?

A. The best time to transplant and divide iris plants is in the fall. Use a garden fork to lift them from the ground. Look for borer holes, and then replant them making sure to not plant them too deeply.

14. What is the best advice for improving soils for growing watermelons?

A. Lighter soils are best for growing watermelons. Add compost to improve the fertility.

15. A gentleman has cherry trees, apricot trees, and peach trees. What type of mulch should be applied to help keep the trees watered?

A. Organic mulches should be used, such as the wood chips. They need to be applied at a uniform depth of 2-3 inches in a ring around the trees that is at least 2-3 feet wide around the tree. Water the trees for about 45 minutes every 10-14 days, more may be necessary during the hot, dry periods of the summer. Use a soil probe or long screwdriver to see if the trees need water. Push the probe into the soil up to 12-18 inches deep, if there is resistance any time while pushing into the ground, the trees need water.

grape hyacinth, ricky layson photography, bugwood
Grape Hyacinth photo from Ricky Layson, Ricky Layson Photography, Bugwood.org via Creative Commons License.

16. A caller has grape hyacinth growing in her lawn. What can be done for management?

A. Mow it off. This is a short lived annual plant that is close to the end of its lifetime for this year. There is no need to use chemicals to control this plant.