DEAR NEIL: My hibiscus plant gets lots of buds, but the stems break before the buds open. I’ve checked for any kind of pests and can’t find any. The plant is healthy otherwise. Why would this happen?
Dear Reader: Your photo shows the issue perfectly. The entire hibiscus clan, including hardy hibiscus (mallows) and tropical types like yours, falls victim to severe aborting of flowers during periods of hot, dry weather and low humidity.
I’ve seen times when althaeas (roses-of-Sharon) dropped as many as half or more of their buds. It’s especially noticeable when we grow tropical hibiscus in pots because those plants tend to dry out so quickly when it gets really hot in early afternoon.
Keep your plant moist at all times and perhaps give it just a little shade from 1 to 4 p.m. and it should fare better. Fall’s cooler weather will help a great deal as well.
DEAR NEIL:What’s working on my pepper plants?
Dear Reader: My guess would be the very tiny chilli thrips (unusual spelling of “chilli” is acknowledged). They have become a serious threat to vegetable plantings and nursery crops in the past 20 years.
DEAR NEIL: I have a 50-foot-tall pecan tree that’s almost 20 inches in diameter. It has been very healthy from 1998 until this summer. This year its leaves have been smaller than normal (see samples enclosed).
Suddenly, they turned brown and my tree appears dead. Could it have been the hot, dry weather? I hate to have it taken out if it’s still alive.
Dear Reader: That really hurts. Pecans don’t die that way very often unless something catastrophic happens such as weedkiller damage, trunk or root injury or serious gas leak – something very exotic. A certified arborist might be able to figure it out if he or she were able to look at it on site.
It’s impossible for me to diagnose the cause from two dried leaves, but it has to have been something more than just drought or casual invasion of insects or diseases. If it’s already brown it’s probably not going to put out any more leaves either this fall or next spring, but if it’s in a place where it won’t hurt anyone or anything if branches fall over the winter, you could leave it in place until spring growth begins so you could know for sure.
If there’s any risk at all, however, I’d be taking it out.
DEAR NEIL: My yard looked great until late spring. I fertilized in March and June. By late June it looked brown and dry. I went to the nursery and they told me it was grub worms and that I needed to treat at the end of winter. What do you think?
Dear Reader: I don’t believe that information was correct. Grub damage is happening right now and is almost completely done by the end of October. The adult June bugs fly and mate in June. Eggs are laid in June and start to hatch a few weeks after. That means that treatment time, if you have grub issues, is late June with Merit.
However, grub worms are not common problems in most of Texas currently. I would almost guarantee that what you saw in June was damage caused by chinch bugs. They were horrible this past summer. As was gray leaf spot fungus.
It is made worse by applications of nitrogen made in hot weather. We should not fertilize between mid-June and early September if gray leaf spot has been a problem in the past.
DEAR NEIL: This photo is of a cluster of plants that came up in our garden in our rural backyard. What is it?
Dear Reader: You are growing All-American ragweed, the source of so many people’s horrible fall allergies. You’ll want to cut it out quickly.
DEAR NEIL: I’m a Texan and I love to garden, but summers are so intense for our plants. We need to stick to types that handle the heat. I just discovered that I somehow have petunia seeds left over. Could I grow them in my greenhouse in the fall and winter, then put them outdoors next spring?
Dear Reader: You’re right on the heat, and petunias are definitely cool-season flowers. If you plant the seeds in your greenhouse now you’ll have flowering plants over the winter, but they’ll be too large and leggy to set out in February.
They would merely be for winter color in the greenhouse. For transplants to set out in late winter and very early spring you’d want to start your seeds in late December or very early January.
DEAR NEIL: I have a 1-year-old zoysia lawn that I’ve maintained at 3½ inches. I’d like to drop it to 2 inches. Would it be better to do that over the winter, or should I start cutting it a little bit shorter each mowing now?
Dear Reader: I’d go with the late winter “scalping.” If you drop it at all at this time it’s going to be brown the rest of the fall, and that wouldn’t be good.
DEAR NEIL: I have amaryllis bulbs I’d like to divide. Should I take them up now, let them dry a little bit and cut off some of the green before I replant them early next spring?
Dear Reader: No. Wait a few more weeks until it’s cooler. Dig and divide them at that time and replant them into freshly prepared garden soil immediately. Don’t go out of your way to let their leaves turn brown.