This is the Q&A for the Yard and Garden show for August 2, 2019. Yard and Garden Live is a call-in radio show I do on KUTT 99.5 FM from 10-11:30 am. 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.
Guest Host: Dennis Ferraro, Extension Wildlife Specialist, UNL
1. The first question of the show was about pole green beans. They were planted in May and have been blooming but have not produced any beans yet. What is wrong with them?
A. This is likely due to the abnormal weather pattern we have seen this spring and summer. Make sure that the plants are mulched and watered evenly, as much as you can. Also, the warmer night temperatures will keep the beans from developing.
2. A caller has lilacs that are 2 feet tall. They have rust spots on the leaves. What is causing this?
A. This is likely due to a fungal disease. Make sure you are watering from the base of the plant and keep mulch around the plants. Fungicides can be used but if it is just on a few leaves, just pull those off and destroy them. It also is a little late to spray fungicides on the plants this year. At the end of the year clean up all the fallen leaves from around the plant to prevent re-infection next year.
3. This caller has turf that continually gets brown patch every year, it is only getting one hour of sunlight per day. What can be done to help reduce this problem?
A. Unfortunately, the turf isn’t growing well in this location. Turf is a full sun plant and needs at least 6-8 hours of full sun per day, not dappled light. In this location the turf will always have problems. It might be a good time to switch to another plant underneath the trees. Shade perennials or groundcovers could replace the turf and they would grow much better there. Sedges are another good choice that look very similar to the lawn but would tolerate the shade better.
4. What can be used for weeds in a driveway?
A. Roundup 365 would be a good option for this. It contains glyphosate as well as imazapic which lasts longer than the glyphosate alone. On the label it states to only apply once a year and to “spray until THOROUGHLY WET”, so for best results spray to this extent. Soil sterilants aren’t recommended because they often run off into adjacent plant material such as grass and kills it. You could also use pre-emergent herbicides in the spring to help with annual weeds. Always read and follow the label when using pesticides.
5. A caller has bagworms in his windbreak. What can be done for bagworms now?
A. It may be a little late in the year to treat chemically for bagworms. Once they get much larger than 1/2″ in length, their feeding is reduced and sprays are not as effective. Also, the majority of their damage is done for the year. If you decide not to spray, it would help to go out and pick as many of the bags off as you can and destroy them.
6. How do you control sandburs?
A. Sandburs are an annual grass, so using crabgrass pre-emergent herbicides in the spring will also kill germinating sandbur seeds. Also, sandburs are easily out-competed, so if you can get something else to grow in the area, the sandbur population will be reduced.
7. This caller has Japanese beetles on Linden trees. What can be done to control them? Will the trees die from this?
A. The trees should be fine next year and will leaf out fine. You can spray the trees now with Sevin or chlorothalonil. Next year, you can spray with these products after the bloom period or when the beetles first appear. Do NOT use a systemic insecticide on linden trees due to the high amount of pollinators that are found on lindens.
8. A caller has a problem with squirrels eating his sweet corn. What can be done to stop the squirrels?
A. For a small plot of corn, you can drape bird netting over the corn and use fishing weights to hold it down. From Control of Tree Squirrel Damage NebGuide “Wire mesh fences (no larger than ½-inch weave) topped with electrified wire or mesh enclosures may be practical for keeping squirrels out of small areas. Electrified wires are not recommended for use where there are children or pets. Little else can be done with squirrels in larger areas, other than re-moving the offending squirrels by cage trapping or shooting where safe and legal.”
9. This caller has an apple tree that is covered with Japanese Beetles. She sprayed Tempo on the tree, can she still use the apples?
A. No, fruit trees are not listed on the label. When using pesticides be sure that the plant you are spraying the pesticide on is on the label. With fruits and vegetables, watch the PHI (pre-harvest interval) to know how long to wait between application and harvest.
10. A caller has pin oaks and something seems to be eating the leaves. The leaves are dying and this is a young tree and he is trying to avoid using pesticides. What can be done?
A. This damage could be from grasshoppers or beetles, most of the damage seems to be happening at night so it could be chaffers that are active at night. Using a neem oil or insecticidal soap would work for these pests as an organic option.
11. This caller is having troubles with a groundhog. How can manage the groundhog?
A. Trapping works best for groundhogs. Put burlap over the cage because groundhogs are spooked easily. Use a half an apple or half an ear of corn for bait. Wire the cage open for a few days to allow the groundhog to take the bait and become more relaxed with the trap. Then, after a few days set the trap without wiring it open. Once you catch the groundhog, you cannot translocate it. It must be euthanized with a firearm if legal where you are or take it to animal control. Be sure to check local laws before controlling this groundhog. For more information, visit wildlife.unl.edu
12. A caller is trying to control his bagworms, what chemical can he use for bagworm control?
A. Tempo is a great choice, but sevin or any other general insecticide will work. It may be a little late in the year to treat chemically for bagworms. Once they get much larger than 1/2″ in length, their feeding is reduced and sprays are not as effective. Also, the majority of their damage is done for the year. If you are planning on still spraying, get it done very soon.
13. The last caller of the year called to say “Thank You!” He removed brome grass competition from around his trees, thanks to advice from the show, and now his trees are growing much better.
*Disclaimer - Reference to any specific brand named product does not constitute endorsement, recommendation, favoring or implied criticism if similar products are not mentioned by Nebraska Extension in Gage County. Identifying specific pesticides are for the convenience of the reader and are generally most commonly available. Always read and follow the pesticide label.