Neil Sperry's Mailbag

DEAR NEIL: What would cause ugly growths on the lower branches of an oak tree? They look like corky masses with worm holes in them. Will they hurt the tree?

Those sound like insect galls. Each species of oak has its own inherent types of galls. The adult insect flies by and stings the twigs and branches. She lays her eggs in the process, and the gall you see is the plant's reaction to the sting. There is nothing you can do to control them galls. The good news is that they, on their own, do nothing to harm the tree. Just ignore them.


DEAR NEIL: You referred to an almond-colored worm recently. Are you familiar with asps? They have a poisonous bite that looks like teeth marks.

Entomologists refer to those larvae as "puss caterpillars," but most Texas gardeners know them as asps as you referenced. They're the immature form of a non-descript moth, and they're common on a variety of landscape and garden plants at certain times of the year. Telltale identifiers for them are their peaked back (not completely round) and their tapered shape. It's among the tan bristles that you'll find those stinging hairs that contain the painful venom. General rule of thumb: teach your children not to handle caterpillars. You never know when they'll run into one of the several types that sting.


DEAR NEIL: I have a neighbor who does not take very good care of the lawn.

Weeds like thistles, dallisgrass, dandelions and a weed that is called dog fennel (Anthemis cotula). I'm sure it spread its seeds to other yards, mine included, before it was removed. How much of a problem will it be for me, and is there anything I can do to prevent it? It's certainly not a common weed in most lawns. But, that doesn't mean that it couldn't invade. Your first step would be to take good care of your existing grass so that it remains dense and low, better able to ward off invaders. Second, you can use a broadleafed weedkiller spray to eliminate any of it that does go ahead and germinate. These are products containing 2,4-d. Read and follow label directions carefully to get the results you want. Or, you could apply a Gallery pre-emergent weedkiller product in late winter to keep it from sprouting. That shouldn't be necessary, however. Actually, I'd be a lot more concerned about having dallisgrass next door than I would to having any type of broadleafed weed.


DEAR NEIL: We have two kinds of weeds in our lawn. One is some type of ivy I can't seem to kill. It stays very low. The other grows tall and has thorns. You can pull on either of them and you'll get a runner that may be 2 feet long. Can I place sod over these as I start a new lawn, or what can I use to eliminate them?

I would try to eliminate them before planting the sod. The thorny plant sounds like smilax briar. It has glossy, heart-shaped leaves, often with silvery markings. Mowing alone will usually eliminate it. In those rare cases when it is so well established that mowing won't stop it, it's usually easiest just to hand-dig the big tuber and mass of roots around its crown.

As for the ivy, the same broadleafed weedkiller spray we mentioned earlier would work on it, but you need to apply it while the weed is growing most actively.

DEAR NEIL: Can I successfully dig and replant a climbing rose that we've had for 4 or 5 years? I need to put a walk around that side of my house now, and the rose is right in the way. When should I do it?

You can certainly move a climbing rose, and early February is the best time to do so. However, transplant it as you would an established shrub, that is, by digging a ball of soil around its roots. Use a sharpshooter spade for the digging. You'll probably want a soil ball that is 16 to 18 inches in diameter for a plant of that age. Cut the top back to about 3 feet before you start the digging. That will compensate for the roots you'll be severing. It will mean that your rose won't bloom next spring, but it will help it survive the digging.


DEAR NEIL: A county agent told me years ago that I could eliminate clover by applying ammonium sulfate fertilizer (20-0-0) to the lawn while the clover leaves are moist with dew or irrigation. It would soon kill the clover, but the grass would not be harmed. Thought you might want to know.

I learned the same thing from my own father. He was in charge of herbicide research for Texas A&M, and we did that to eliminate clover in our lawn in College Station when I was a teenager. However, that was a long time ago, and the modern broadleafed weedkillers are far more dependable now. Those fast-release nitrogen fertilizers are damaging to turfgrasses in that they cause excessive bursts of growth and can lead to thatch accumulations.


Have a question you'd like neil to consider? Mail it to him in care of this newspaper or e-mail him at mailbag@sperrygardens.com. Neil regrets that he cannot reply to questions individually.

Neil Sperry
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