GARDENER'S MAILBAG: What are these insects?
Dear Neil: These insects have appeared on our green tomatoes. We’ve never seen them before. What should we do?
These are immature leaf-footed bugs (Leptoglossus pyllopus), close relatives to stinkbugs. They have similar piercing mouthparts. They will suck the fluids out of your ripening tomatoes and cause yellowed spots in the fruit in the process. They are also vectors for tomato diseases. Spinosad offers reasonably effective organic control, or some people actually vacuum them off the leaf surfaces with a shop vac. Sevin (Carbaryl) gives good control as well.
Dear Neil: My Lacey oak (photo attached) has developed oak wilt. I’ve trimmed off many of its lower branches. What more should I be doing?
Let’s do a complete reset. I have both Lacey oak and Chinquapin oak growing in my landscape (and several other types of oaks). This certainly looks like a Chinquapin oak. And it does not look like oak wilt. If that’s the case, that would be great news. It looks like old remnants of oak leaf blister. It was rampant this past spring due to the rainy weather in many parts of Texas. It’s a fungal leaf disease that attacks many species of oaks, but that normally doesn’t do any measurable damage. My take on it would be that no matter what the issue might be, it’s so late in this growing season that I wouldn’t try spraying anyway. The branch still looks vigorous. Sit tight and wait until spring. I’ll bet it will be fine.
Dear Neil: Like so many others, I lost my citrus trees down to the ground in last February’s cold. They have sprouted from their bases, but now the sprouts have so many large thorns. Can I allow them to continue to grow until I could graft a good branch from a new tree to take advantage of the established root system? When would I do it?
It certainly could be done, but as a quiet voice of experience, I can tell you that success in budding and grafting depends on speed and technique. Your first 100 grafts will be your worst 100 grafts. Put in other words, there’s a steep learning curve. You have to become fast at the task so the tissues don’t dry out. I encourage people to play around with grafting as you’re describing, but to replace frozen trees with healthy, vigorous new plants of varieties they want.
Dear Neil: We have a lovely oak that we may have planted too close to the house (12 feet from the nearest corner). Its roots are growing on, or very near, the soil surface and they seem to be growing toward the house. We love the tree and we really don’t want to have to take it out. Is there any solution?
Yes. Work with a certified arborist this fall, once the hottest weather has passed. Have a barrier installed to prevent the roots from growing any closer than 4 or 5 feet from the foundation. Cut a narrow trench 15 or 16 inches into the soil, taking great care to avoid utility lines in the process. The arborist will have a suggestion, but I use vinyl pond liner or corrugated fiberglass laid on edge as my barrier.
Dear Neil: How can we address poison ivy that has invaded mulched beds around our oak trees?
Assuming there are no other plants than the poison ivy and trees in those beds, you could apply the broadleafed weedkiller 2,4-D by itself (as opposed to mixes containing two other active ingredients). The additional herbicides are active in the soil and through tree roots, while 2,4-D is not. As long as you apply 2,4-D under low pressure and in still wind conditions you won’t harm the trees. It is very effective at eliminating poison ivy.
Dear Neil: We replaced old shrubs with azaleas after the freeze. The plants get seven hours of sunlight, but the leaves are really sickly looking. I’ve sprayed with Daconil two weeks apart, but that didn’t seem to make a difference. I can’t tell what to do. Help!
The leaves have definitely been hit by a fungal leaf spot. However, if you sprayed after they were infected, then those particular leaves won’t green back up again. Seven hours of direct sun is a lot, especially if they weren’t planted in really well-prepared azalea mix. That’s not as critical in East Texas where soils are acidic, but from I-45 west it becomes a deal-breaker. They must be planted in a very acidic peat/pine bark mulch combination. It also looks like your plants might have gotten too dry one or more times, and that, too, would be irreversible for those leaves. Hopefully next spring will be better. You might even consider moving the best of them to a spot that has afternoon shade.
Dear Neil: Why are my pecans falling now? They’re also turning black and watery a day or two later.
That’s due to pecan scab, a fungus that attacks the pecans clear back in early summer. There is nothing you can do about it now. If you’re spraying for pecan casebearers, hickory shuckworms and pecan weevils during late spring and summer, include a fungicide for pecan scab with each application.
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