Neil Sperry's Mailbag

DEAR NEIL: We had an old hackberry tree, and now mushrooms are coming up all around where it was. Bleach hasn’t helped stop them. Help with a spooky problem.
You’re worrying way too much. Mushrooms are saprophytes -- they live off dead and decaying organic matter. They’re beneficial in the whole scheme of nature, and they’re harmless to you.

Of course, you should never harvest unknown mushrooms for consumption, but just leave them alone to do their job in your garden. Once the tree’s wood has all rotted, they’ll go away.

DEAR NEIL: We have a sago palm that is now more than 5 feet across. When can I transplant it? Do you have any other tips?

Transplant it late in the winter, as the danger of hard freezes abates.
Retain a ball of soil in place around its roots. You may have to tie its leaves up and out of the way in order to get a sharpshooter spade into the ground beneath the leaves.

DEAR NEIL: My husband ordered tomato seeds this past winter. They have grown into nice plants, but so far we have had only three or four blooms and only three small tomatoes. What is wrong?

When a tomato plant grows well but doesn’t bloom, it’s usually due to insufficient sunlight. They require full sunlight all day long to reach maximum productivity. When a plant blooms but doesn’t set fruit, that’s due to a lack of pollination. Tomato flowers are self-pollinating. That means that the pollen that fertilizes the flower is produced within the same flower (not transferred by bees). It requires mechanical agitation (wind or vibration). If you get more flowers, try thumping the flower clusters with your fingernail every couple of days to jar the pollen. Finally, only small- and medium-sized varieties will set well in the heat of a Texas summertime.

Large varieties like Big Boy and Beefsteak quit setting when daytime temperatures climb beyond 90 degrees.

DEAR NEIL: I bought the tree in the photo attached two years ago. It was supposed to be a Texas ash, and I wanted it for shade. It looks like it’s dying. I want to cut it down, but I’d still like to know what it is.

This is, indeed, a Texas ash. Unfortunately, it’s been weakened by borers in the trunk and major branches. Ash trees are especially vulnerable. Replant with something better.

DEAR NEIL: I planted some windmill palms two months ago. They seem to be growing fine, but the lower leaves seem to droop. Is that normal? My sprinkler system applies about 1 inch of water weekly. Should I be giving them more?

The best way to tell if a plant needs more water is to soak it heavily one time, then wait overnight to see if it rebounds. If you see new growth, the plants are doing well, but it would still be a good idea to hand-water it halfway between times that your sprinklers run.

DEAR NEIL: How can I get bermudagrass out of my Asian jasmine bed?

Many landscape contractors and home gardeners use glyphosate herbicides for this job. Of them, Round Up is the most common brand. This use is not on the products’ labels, but it can be applied at the rate normally used to kill bermuda. So applied, it should not harm the Asian jasmine. However, you assume that risk. Try a small area first, to see if you’re happy with the results. Do not attempt it with any other type of groundcover.

DEAR NEIL: Something is attacking my angel’s trumpet (Brugmansia). You can see the white insects that are stuck to its leaves, and there are small, black insects there, too. What can I use to control them?

The white pests are scale insects. These adhere to leaf and stem tissues and suck the life right out of their host plants. Control them with a systemic insecticide such as Merit or acephate. I didn’t see the black insects on your sample, but they are probably not doing as much damage and the insecticide will probably control them anyway.

DEAR NEIL: We have a Shumard red oak (see photos) that is approximately 4 years old. It has had full, even foliage all of those years until now. Can you tell from these photos what might have caused the branches only to have tufts of leaves at many of their ends?

The cause is probably farther down in the main trunk. Most of the times when I’ve seen this kind of damage, there has been either decay or borer involvement. Often, it shows up 3 or 4 years after planting, and it’s usually because a tree’s trunk was not protected with paper tree wrap from the time it was planted. Red oaks and Chinese pistachios are especially vulnerable to sunscald since they have minimal bark protection. You probably need to get a certified arborist to look at the tree in person.

DEAR NEIL: Why are so many leaves dropping from my fruitless mulberries? Is it iron deficiency?

Large-leafed trees start shedding leaves by mid-summer each year. That’s especially noticeable when it first turns hot and dry for several weeks. It is definitely not iron deficiency. Plants that lack iron have yellowed leaves with dark green veins, with the yellowing being most pronounced at the ends of the branches. The affected leaves don’t fall off. Best remedy for your problem: water deeply when you irrigate, and keep a rake handy.

DEAR NEIL: We’d appreciate your help in dealing with our St. Augustine lawn. Light green areas have appeared on one end of the lawn the past couple of summers, even though we have used a quality lawn food followed by a well-known liquid fertilizer. Still, the one area remains light green.

Odds are your lawn has developed a gray leaf spot problem. That’s a fungal disease that hits in the summer.

Affected leaves (and often runners as well) will have diamond-shaped and b-b-sized gray/brown lesions along their midribs. Fungicides will help slow the disease, but you should definitely avoid nitrogen fertilizers in the summer. Fertilize the grass April 1 and repeat it June 1, then wait until mid-September to feed it again.

DEAR NEIL: I’ve read about how you can change the colors of your hydrangea by using unusual fertilizers. However, I can’t get my plant to bloom at all. What might I have done wrong?

Greenhouse growers refer to those as “blind” shoots in their hydrangeas, and they’re devastating for the sales value of that plant. If they receive much cold in the winter, the plants will freeze back rather drastically. That, more than anything, will cause failure to bloom. Hydrangeas that have frozen back respond with very vigorous new leaf and stem growth, at the very great expense of their reproductive floral bracts. Your best bet in future years would be to protect the plant just a bit when it’s going to be cold.

DEAR NEIL: About 10 years ago my husband brought East Texas cane into our landscape. It has grown very vigorously, in fact, invasively. Now it’s coming up in many places where I don’t want it. I’ve tried Round Up sprays at full strength after we cut it back, but, two months later, it comes back. We want to build a new concrete drive, but I’m afraid the cane will come up through every crack in the concrete. Help!

Assuming you have the true cane (one-inch-wide leaves), you should be able to eliminate it with one of the glyphosates such as Round Up. Spray when the growth is 3 to 4 feet tall, not right after you cut it. Be sure the spray coats the leaves, and protect desirable plants nearby from any drift that might hit their leaves. Do not use the material at full strength unless it’s a ready-to-use formulation. Using a weedkiller at a very strong ratio sometimes can burn foliage without actually killing the entire plant as you have wished. You can also dig cane out with a steel-handled sharpshooter spade. If you decide to do that, wait until the soil is well saturated following a rain.

Neil Sperry
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