This is the Q&A for the Yard and Garden show for July 13, 2018. 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 3, 2018. 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: Bob Henrickson, Horticulture Program Coordinator for the Nebraska Statewide Arboretum
1. The first caller of the day has a bug zapper that was recently emptied. The zapper contained quite a few of these small, brown, bean seed-shaped insects. What would this insect be?
A. Based on this description, it could be June bugs. These smaller, copper colored beetles are common right now and they are attracted to lights at night. If you have a lot of June bugs, you may want to pay close attention to your lawn and any possible brown spots in it. The immature stage of June bugs are white grubs that feed on the roots of our turf.
2. A caller has a climbing rose that is 8-10 years old and it was recently cut down to about 15 inches tall, against the homeowners wishes. Will this plant survive?
A. This isn’t the ideal time to prune a rose, but it should be fine since prior to the pruning it was in very good condition. Make sure to keep the rose well-watered and keep a layer of mulch around it to keep it healthy during this time of heat as the rose will try to push new growth. Water it with 1 inch of water per week unless natural rainfall provides that. Keep the mulch 2-3 inches deep.
3. This caller has an elm tree that has a hole in the base of the tree that goes in about 1 foot deep. Will the tree be ok?
A. A picture was requested for this tree to determine the severity of the hole. This could be due to many different factors including a crown rot, root rot, or other type of root damage. The hole is not very large, but because it is a foot deep, there is a concern for the strength and stability of the tree. Keep an eye on the hole, if it gets larger or if the canopy starts to thin, it would be a concern that would need to be removed before it falls on something.
4. A caller has a black spot on the bottom of his tomatoes. What is causing this and can it be cured?
A. This is blossom end rot, it is where the blossom end (or the end of the tomato farthest from the plant) rots. It is due to a calcium deficiency due to uneven watering. The calcium is in the soil, but uneven watering makes it unavailable to the plant. Mulch will help keep the soil at a uniform moisture level to help protect plants from this disorder. Blossom end rot is a short-term problem in our vegetable crops. It tends to only affect the plant for a the first couple of harvests of the year and then the plant grows out of it. You can cut the black end off of the fruit and eat the rest.
5. This caller has a tropical hibiscus that she has moved outdoors for the summer. This hibiscus was looking fine but now some of the leaves are turning yellow. She waters every other day and it is on a wood patio on the south side of her home. What is causing this yellow color?
A. This could be heat stress due to the fact that this plant is in a location on the south side that gets very hot. She also should test the soil with her finger prior to watering to be sure to not overwater. If the soil is dry, water. If the soil is still wet, wait longer before watering again. This could also be due to spidermites. You can test for spidermites by placing a sheet of white paper below a few of the leaves and tapping on the leaves. If a few pieces of pepper seem to be moving on the paper, that is spidermites. If it is spidermites, the plant can be sprayed with a strong spray of water to knock the mites off and kill them or you can use Eight (permethrin) on it.
6. A walk-in listener brought in a plant that he needs identified. It is growing like a shrub with orange and red berries and it is spreading rapidly. What is it?
A. This is a plant called Tatarian Honeysuckle, it is a weedy species. It is spread rapidly by birds. Cut it off now before it becomes more established. Treat the stumps with Roundup or Brush Killer.
7. Does 2,4-D work on sandburs?
A. No, sandburs are a summer annual grass like crabgrass. Using a pre-emergent herbicide in the spring for crabgrass will control sandburs as well. If you didn’t use a pre-emergent in the spring, Roundup would work on sandburs but 2,4-D will not be very effective.
8. This caller has chokeberries that are about 4-5 years old and starting to set on. How do you know know when they are mature for harvesting?
A. At this point of the year, there should be clusters of small green fruits setting on the shrubs. The berries will turn dark purple in color when they are mature. There is a large harvesting window for chokeberries and the birds don’t come to this plant until after clearing the berries off of more preferred plant species.
9. A caller has sunflowers that were planted from seed and they have been coming back. The plants are similar to other sunflower plants seen around town but the flowers are much smaller than neighbors’ flowers. Are there different types of sunflowers?
A. There are a lot of different varieties that would influence the size of the flowers. Sunflowers are annual plants, so if they are coming back each year, they are coming back from seed. Sunflowers may not be true to seed so the type of flower may have changed over time or from year to year.
10. This caller wondered if the caller from question #7 may have been referring to puncturevine as they are commonly confused?
A. These plants do commonly get confused because they both produce a seedhead that sticks to your clothes or shoes. They are both annual plants as well. However, puncturevine is a broadleaf while the sandburs are grasses. A 2,4-D product will work to control puncturevine, but the pre-bloom stage is going to be most effective.
11. The final call of the day has bugs flying around their tomato plants and eating the tops of the fruits. What is that?
A. After seeing a photo of the damage to the fruits, it was determined that this is due to the tomato fruitworm. Tomato fruitworms can be controlled with sevin or eight. If there are insects flying around the plants as well, that is likely something different such as Japanese beetles. It is possible, and likely, that this caller has multiple insect issues. However, both of these pests will be controlled if he sprays for one, they are both affected by the same pesticides.