This is the Q&A for the Yard and Garden show for August 3, 2018. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am this was the final episode for 2018. It can be found again next spring on kutt995.com for online listening. If you enjoy reading my Q&A from the show each week, take my quick survey at: go.unl.edu/yardandgarden18 and be entered to win a free tree diagnostic book.
Guest Hosts: Kevin Christiansen, Horticulture Instructor at SCC Beatrice & Evan Alderman, Turfgrass Management and Horticulture Instructor at SCC Beatrice
1. The first caller of the day has a windbreak that has elms growing in it. How can he kill the elms and not harm the windbreak trees?
A. In this situation you need to use a herbicide that will kill the elms but will not be translocated through the roots into the surrounding windbreak trees. Tordon should NOT be used in this location. A good option would be either glyphosate, Roundup, or a 2,4-D product. Use these 2 products as a stump treatment on the tree just after cutting the tree off.
2. A caller has cucumbers that are blooming but are not producing any fruit yet. Why are the cucumber not producing? This caller also wondered how to control puncturevine?
A. The cucumbers could be due to no female flowers, if all the flowers are male, they will not produce any fruits. Sometimes our plants start with just male flowers and the females will come in later. It could also be due to low pollinators around the plants. If not many bees or beetles or other insects are found around the plants, they cannot be pollinated and may need to be hand pollinated. Hand pollination can be done by running a cotton swab through all of the blooms, this would move pollen from male flowers to female flowers. Puncturevine can be controlled with a 2,4-D product in the fall. Apply the 2,4-D in mid-September and in mid-October.
3. When should you transplant surprise lilies?
A. Surprise lillies can be transplanted or divided just after the flower dies back in the fall.
4. This caller has foxtail in the vegetable garden. Can anything be sprayed in the garden to control the foxtail?
A. There is nothing that can be sprayed over a garden to control foxtail and not harm the garden plants. The best option would be to use preen in the spring and summer to stop the germination of annual weeds such as foxtail. Be sure to use the preen that is labeled for use in a vegetable garden and wait until after all seeds planted have germinated. Mulch would help suppress the weeds in the garden as well. Grass clippings, straw, or other organic mulches will help keep the weeds down to help your vegetable plants grow better.
5. A caller was looking for assistance choosing fruit trees for his acreage. He also has rust on his fruit trees and wants to know how to manage it.
A. There is a great NebGuide on Fruit Tree Cultivars for Nebraska. For rust, this is not the correct time to treat for it. You can spray your trees in the spring with a liquid copper fungicide. For more on care and pest control of your fruit trees, visit: https://food.unl.edu/local-food-production
6. This caller has a windbreak of Red Cedars that are losing limbs. The trees are 100 years old and 30 feet tall. What is wrong with them?
A. This could be due to old age. It may be a good idea to start a new row of trees on the inside of the old row.
7. A caller has nutsedge in his lawn. What can he spray it with and can he still spray it?
A. Sedgehammer is the best control for nutsedge. It can still be sprayed now, however more control will be achieved if applied in the beginning of June, prior to the first day of summer. If sprayed before June 21st, nutlet production will be reduced, thereby reducing the population for the following year.
Tree planting in the fall
8. This caller wants to know when the best time is to transplant an oak tree?
A. Fall or Spring are both good times to transplant a tree.
9. How do you control cattails and water lilies in a pond?
A. Rodeo is the glyphosate product that is labeled for use in water and it can be used on both of these weeds.
10. How can you control crabgrass and nutsedge in a lawn
A. Quinclorac can be used now for both of these weeds. Or use a pre-emergent herbicide in the spring and again in June for the crabgrass and sedgehammer for the nutsedge in June. Tenacity is another product that should work on both of these weeds.
11. A caller wants to know why we should worry about getting rid of cattails and water lilies in a pond?
A. Weeds in a pond can strangle the waterways or destroy habitat for fish. Some plant life along the edge of the pond can be beneficial, but too much can be a detriment.
12. This caller has lilies with caterpillars in the stem. What are those and how can they be destroyed?
A. This is likely a cutworm. Sevin or eight or Bt applied at the base of the plant can help kill these pests before they damage your plants.
13. When is the proper time to apply a winter fertilizer on a lawn?
A. Fall fertilizer can be applied in late August to mid September and the winter fertilizer can be applied in the middle to late October. It is no longer recommended to apply the winter fertilizer in November as previously recommended.
14. A walk-in listener has a weed they need identified and they need to know how to control it?
A. This is a weed called nimblewill. It is a warm-season grassy weed. It can be treated either with Roundup or Tenacity. If you use Roundup and reseed, apply the roundup now, while the nimblewill is still green and then overseed in a couple of weeks through the end of September.
15. This caller has spaghetti squash that was looking great and then one day it just died. What caused it to die and how can the other plants be protected?
A. This is likely due to squash vine borer. You can use sevin or eight to protect your plants from the squash vine borer. Be sure to apply it at the base of the plant where the plant comes out of the ground. These chemicals will need to be reapplied every 10-14 days throughout the growing season to protect the plants. Otherwise, you can wrap the base of the plant in aluminum foil to prevent the borer from getting into the plant.
16. A caller has watermelons with yellowing leaves. This has happened to his plants 3 years in a row now, he does rotate the crops in the garden. This damage starts at the base of the plants and will eventually kill the whole vine. He has mulch on the garden and waters slowly with a hose for 2 hours at a time. What is causing this problem? Also, when do you transplant iris?
A. This looks to be alternaria leaf spot. He is doing many things to prevent this disease already with mulch and his watering practices. It might be beneficial to try a liquid copper fungicide this year and next year as soon as the symptoms begin. Iris can be transplanted in the fall, September or October would be best.
17. A walk-in listener has a tree they want identified and they want to know why it keeps suckering and what they can do with the suckers?
A. This is a silver maple tree, they are prone to suckering. Suckers should be just cut off as they grow to reduce the amount of energy they take from the main tree. Do not treat the suckers with anything as that could injure or kill the main tree because the suckers are growing off the main tree roots.
18. This caller wants to know why their pepper plants are not growing well?
A.The peppers are planted too closely to a black walnut tree and will not grow well in that location. Black walnut trees produce juglone, which is basically a naturally produced weed killer. Certain plants are more sensitive to juglone, tomatoes and peppers are quite sensitive. The garden should be moved to at least 50 feet from the black walnut of the plants should be grown in a container or raised bed to avoid problems with the juglone.
19. The final caller of the year has hostas planted in a rock garden and they are not growing, they are still small like they were just planted there.
A. The rock garden may be too hot for the hostas and the rocks do not provide any nutrients back to the plants. It might be best to switch to a wood chip mulch to help reduce the heat and add some nutrients and organic matter to the soil.
This caller also wanted to know what to do to kill the bindweed growing in her Iris beds?
A. Among other plants it is best to use the “glove of death” which is when you wear a chemical-resistant glove and then put a cloth glove over that. Then, dip a few fingers of the gloved hand into Glyphosate and rub those fingers along the stem and leaves of the bindweed to kill it. Basically, the idea is to keep it from flowering and producing more seed, hand pulling will help keep new seed from being deposited into the garden which can be viable for up to 60 years.