This is the Q&A for the Yard and Garden show for July 30, 2021. 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 and will continue to do so throughout the season. This is the last show of the summer season for 2021. We will have 2 fall episodes on September 10 & 17.
Guest Host: Jody Green, Extension Educator and Urban Entomologist from Douglas/Sarpy County Extension
- The first caller of the day planted new apple trees. He has been watering twice a week and now the trees have brown spots on the leaves. What is causing the brown spots and how can they be controlled?
A. It is most likely that these trees are susceptible to cedar-apple rust or apple scab. They will need to be sprayed in the spring every year or they will have spots on the leaves every year. It won’t kill the tree to have either of these diseases but it they will look bad most of the season. Use a copper fungicide in the spring or an orchard fruit tree spray to manage the disease. For more information on managing fruit trees, visit the UNL Local Food Production website.
2. How can you manage Japanese Beetles? Do you need to manage the grubs as well?
A. Japanese beetles are best managed by hand picking and destroying or spraying plants with an insecticide. At 7pm, the beetles are bunched up. Place a bucket of soapy water underneath plants where they are bunched and tap on the branches to knock the beetles into the bucket. You can also use sevin to control them. Don’t use traps, those attract more than you have. Grub control can help but won’t eliminate the problem because they will still fly in as adults from nearby locations. Treating grubs will help with the damage to the lawn but not necessarily with the damage to other plants from adults.
3. This caller has cedar-apple rust on his apple trees. Is there a fall treatment to help the trees?
A. No, fall treatments wouldn’t be effective because fungicides are a preventative not a cure so they need to be sprayed before fungi appear. It is best to spray the trees in the spring to protect the new leaves as they are emerging. Here is a NebGuide to view for more information on Cedar-apple rust.
4. A caller sent a photo of insects that are damaging his knockout roses. What are they and how can they be managed?
A. These are Japanese beetles. They are difficult to control and have no predators here. Japanese beetles are best managed by hand picking and destroying or spraying plants with an insecticide. At 7pm, the beetles are bunched up. Place a bucket of soapy water underneath plants where they are bunched and tap on the branches to knock the beetles into the bucket. You can also use sevin to control them. Don’t use traps, those attract more than you have.
5. When should fall crops be planted?
A. They can typically be planted around the end of July to the beginning of August in southeast Nebraska. You can figure out a good date range by using the seed packet. It will tell you how many days to harvest. Use that number and count back from the first frost in your area. You should add 14 days for a fall factor because the plants will grow a little slower and have less light in a day. The average first fall frost date for Gage County is the end of September to the beginning of October. There is a good NebGuide on fall gardening that will help with all of your fall gardens.
6. This caller planted hydrangeas this spring. Has now been watering every other day with a water wand but they look sad because the flowers are turning brown. What can be done to improve the plant?
A. The flowers are fading due to natural bloom time ending. This is a natural process for the plants and nothing to be worried about. You can cut the spent blossom off of the plant if desired to clean up the look of the hydrangea.
7. A caller has some peonies that were accidentally cut off. What will happen to the plants since they were pruned at the incorrect time of the year?
A. It isn’t the best time of the year for the peony, but it should be just fine. Peonies need to be left to grow through the season to allow them to build sugars for the next year. They shouldn’t be pruned back until they turn brown in the fall. However, in this case, it was accidental and the plant will survive. It may mess up the blooming for next year and you may not get as many blooms or any at all, but it should be fine.
8. This caller has 10-12 hills of pumpkins. He is trying to grow large pumpkins for his fall display. The vines have a lot of blooms on them. Should he remove excess blooms to focus on 1-2 for larger pumpkins?
A. Yes, that is what a lot of the “largest pumpkin winning” growers will do. Allowing the plant to produce many pumpkins will push the growth into a lot of pumpkins and they may not grow as large, but forcing the energy into just a few pumpkins per vine should lead to larger pumpkins.
9. The final caller of the show has plants that are flopping over and have a dead center. This is many different kinds of plants growing in rock mulch with drip irrigation that runs twice a day for 20 minutes each time. What is wrong with them?
A. This is likely due to over irrigation. Run the irrigation system with a catch can to know how much water is being applied each time the system runs, but the plants should only receive 1 inch of water per week. Perennials only need to be irrigated once per week for that. It seems that the plants are developing a root rot because they are not allowed to dry out a bit between watering and that is causing them to flop over.
*Reference to commercial products or trade names does not imply endorsement by Nebraska Extension or bias against those not mentioned.
NEW THIS YEAR: If you would like to hear the full recording of this show, Listen to the Podcast found at: https://yardandgarden.buzzsprout.com
Plants and Pests with Nicole 