Neil Sperry's Mailbag

DEAR NEIL: Is it natural for a Texas red oak to lose a lot of leaves in late summer?

It was normal in this summer. Many trees' leaves were afflicted with mildew and other fungal diseases due to the rain.

It wasn't uncommon to see trees that had lost 20 to 30 percent of their leaves in late July and August.

They should be fine in more normal spring and summer conditions in future years.

Of course, if you see any other symptoms of an associated problem such as trunk or root damage you probably should call in a professional arborist.


DEAR NEIL: I have an old pecan tree. I'd like to hire a person to graft a better variety to it. Are there people who do that work?

Would I be better off planting a new tree?

County Extension offices across Texas maintain lists of people who will do grafting.

It's a very precise science and not every city will have someone able to top-work a tree successfully. If it were my tree I would enjoy it for its shade as long as it was healthy.

You can always buy pecans for just a few dollars. Shade is irreplaceable, especially if it's in a prime spot in your landscape. Plant a good variety somewhere else on your property if you can.


DEAR NEIL: Where is information available on planting dates for fall vegetables? I'm getting nervous that I've waited too long.

You'll find that help in many places. Texas-based gardening books and magazines certainly have it.

You'll find answers to all of your questions online at aggie-horticulture.tamu.edu. Most people do, indeed, wait way too long to plant their fall vegetables. The plants hardly get established and growing well before cold weather shuts them down.


DEAR NEIL: I may have killed three live oak trees. This spring I put several potted plants on the ground near their trunks. Now there is a fungus growing up their trunks and they have lost almost all of their leaves. Is there any hope of saving the trees?

There is no way of knowing without seeing the trees first-hand. Contact a certified arborist for a home visit. One thing is almost certain, however - the potted plants had nothing to do with the trees' problems.


DEAR NEIL: My azaleas have little brown specks on the backs of their leaves and the front green color is just splotchy. Is this a disease?

That's damage from lace bugs. The specks on the backs of the leaves are their droppings. You'll see them as well on pyracanthas, Boston ivy, sycamores, elms and oaks. The damage, while a bit weakening, is certainly not fatal. Apply a systemic insecticide next year if and when you see the first signs of the mottling.


DEAR NEIL: My hibiscus plants get buds but they fall off without ever opening. What can I do?

That's almost always due to big swings in available moisture. Be sure the plants are always moist. They should never wilt and, of course, they should not be in waterlogged soils, either. They need full or nearly full sunlight and high-nitrogen fertilizers, but those probably aren't the sources of your current problems.


DEAR NEIL: Can I dig or trim an overgrown sago palm that has outstayed its welcome?

Yes. You may be able to cut it into divisions. Trim away any unneeded leaves but remember that new growth will develop slowly. Late winter is the best time.


DEAR NEIL: I have had brown patch in my St. Augustine for many years. I've heard about putting detergent on it. I've heard of using peat moss. Nothing has worked. Please help.

Beware of diagnoses. There are that many possible problems. However, you should use a labeled fungicide product for brown patch (dying or dead leaves that pull loose from the runners with little resistance). I'm not an advocate of detergent. Take all patch is the disease for which a half-inch layer of peat moss is of benefit, but you need to let a Texas Master Certified Nurseryman confirm its existence.


DEAR NEIL: Can we eat the pecans that have fallen due to pecan scab?

No. Their kernels are ruined. Make plans to spray next time around.



DEAR NEIL: Can I trim a fig tree that has grown too large for its area?

Yes, but it is not good for them. Figs produce best when they grow deliberately, hence the reasons not to prune heavily or apply too much fertilizer. Do as little as you can get by with.


DEAR NEIL: Can I use Roundup to kill existing grass beneath live oak trees? I don't want to harm the trees.

Yes. The glyphosate products are rendered inactive as soon as they hit the soil. Be sure the product contains nothing other than the glyphosate, however. Talk to your nurseryman.

Neil Sperry
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