Neil Sperry's Mailbag

DEAR NEIL: My magnolia tree's limbs are rubbing our house. I want to prune the branches, but I don't want to cut them off clear to the trunk as it would leave too big a gap. Can I cut limbs back partially, and, if so, when should I do it?

You can trim magnolias at any time you need to. So long as don't leave stub ends on the branches you cut, you should be able to cut them back partially.

It really sounds like you might have your tree too close to your house. I have a Little Gem southern magnolia about 5 feet from our house. I have trimmed its limbs up and over the roof. Perhaps you'll eventually be able to do the same.


DEAR NEIL: Is it better to tie up palm leaves and cover them when cold winter weather comes through? We have two, and the bigger one is 12 feet tall. I'm not sure I can cover one that tall.

Consider covering tender plants, palms included, with the lightweight white frost cloth. Local independent retail garden centers stock it. That will lessen the impact of the wind and it will gain you several degrees of protection.


DEAR NEIL: How much cold can sago palms tolerate?

They are winter-hardy into the high 20s. Below that, you're likely to lose them. Of course, they're always suited to containers, at least until they outgrow available space indoors.


DEAR NEIL: We brought loads of soil when we moved into our house several years ago. The existing soil consisted exclusively of stone. We have a Little Gem magnolia that was a little less than 2 feet tall. Now, three years later, it's 10 feet tall. Still, we had only 5 flowers this year. What can we do to get more flowers next year?

Be more patient. Flowering trees, magnolias included, seldom bloom for their first 5 or 6 years (or longer). The facts that your tree has grown that well and that it at least offered to bloom a few times are both remarkable. Give it time and you'll be handsomely rewarded. You're doing great.


DEAR NEIL: Our dogs have trampled our St. Augustine out of existence. Now bermuda has taken over. What can I do to eliminate the bermuda so that I can get St. Augustine to fill back in?

In a short answer, keep the dogs off the area. St. Augustine is the dominant grass of the two so if you keep the dogs away, the St. Augustine will take over for you. Plug it into the bermuda next spring. Checkerboard your plugs on 18-inch centers and they'll cover the first summer.


DEAR NEIL: What is the best product to eliminate grassburs (sticker burs) from my lawn? They have taken over.

Apply a preemergent weedkiller such as Team or Dimension in early March and again in early June. These are granules. Apply them with your fertilizer spreader, then water the ground lightly to help them form a layer across the soil's surface. These are safe on any type of lawngrass, and they can be applied beneath trees and shrubs. Do not use weed-and-feed herbicides as they risk too much risk to your trees.


DEAR NEIL: Our sago palms have a scale insect that eventually kills the plants. I've tried Sevin and Malathion but with no good results. What would be better?

Try a systemic insecticide such as acephate (Orthene) spray. Remember that the scale insects will remain in place even after they have been killed. If they're dry and flaky two or three weeks after you spray them you will have killed them.


DEAR NEIL: I was putting lights into my oak trees this weekend and I observed an almond-colored worm that curled into a ball when I tried to pick it up. Is it harmful?

There are scores of types of caterpillars on our landscape plants right now.

Any damage they will do this late in the season would be extremely minimal so don't worry about treating for them. The exceptions, of course, would be cabbage loopers in the vegetable garden. That said, be very careful in picking up caterpillars. We have several types that can inflict serious stings from the hairs on their bodies. Unless you know a species is safe, it's best not to touch them.


DEAR NEIL: Why would mesquite beans not be filled out this year? Could it have been the rain or cooler weather in late spring and early summer? I promised some to a lady who was going to use them for mesquite bean jelly, but they never showed up.

There may be some more specific reason, but I can't think of it. Lots of our plants behaved strangely this year.


DEAR NEIL: If I planted a large pecan several years ago, will my new tree produce the same type of pecans?

No. The pecan you planted was a hybrid that had been selected for its fruit size. Unless it was grafted, every pecan tree in Texas is actually a hybrid. They are cross-pollinated by wind, so there is no telling what you might expect.


DEAR NEIL: I have various pine roots that are coming up in my soil. When is the best time to remove them, or can I? Do I need to spray the cut roots with anything?

Fall is the best time to remove exposed tree roots since it allows the impacted trees 6 or 7 months to replace them with deeper roots. However, you may not want to remove more than one or two roots of significant size in any one fall, especially with pines. Talk to a local certified nurseryman.


DEAR NEIL: How can I eliminate clover in our yard? My husband has tried many products including pre-emergents and weed-and-feed types, and it's still there.

You need to use a broadleafed weedkiller spray while it is actively growing in late fall or early spring.

There are several brands on the market. Look for the ingredient 2,4-d. Let your nurseryman show you the options and explain the steps to successful control. It shouldn't be too difficult.

It's always best to apply herbicides alone as opposed to the weed-and-feed combinations. If he wants to use a pre-emergent, it would need to be a Gallery product applied in very early September.


DEAR NEIL: I have a beautiful 9-year-old red oak tree that has been afflicted by some type of fungus. For three years it has put out new leaves in the spring, but they remained stunted and pale green in color with dark green veins. By late summer they turn brown and fall off. This autumn I've had other new leaves similar to the spring. Other red oaks nearby look great. This is in white, chalky soil.

Your tree is suffering horrible iron deficiency. You have listed the textbook symptoms. It is usually caused by our planting a red oak that is not a true Shumard red oak into alkaline soil. Pin oaks look almost identical to Shumard red oaks and will not survive alkaline conditions for more than 6 to 10 years. Adding iron in that situation will be of no help since the problem will only get worse. The only other possible cause (and also the one that might hold in areas with acidic soils) would be severe trunk damage that now limits the flow of nutrients to the leaves. That could have resulted from sunscald or borers after the tree was planted. In both cases it sounds like it's time to replace this tree. Talk to your nurseryman for a second opinion.


DEAR NEIL: What is the best time to dig and divide banana clumps? I tried it in October one year and they died.

Try very late winter, just before the new growth starts for the spring. Use a sharpshooter spade to cut through the masses of roots.


DEAR NEIL: I saw your answer about spraying pecans and fruit trees. I tried Googling it as you described and I didn't get anywhere. Do you have other suggestions?

I did both Yahoo and Google searches and found a variety of links. However, a few of them are outdated and should be taken down. The best way to get the most current information is to go to the Texas Cooperative Extension's online bookstore and click through to whatever topic you wish. In your case, you're looking for bulletin E-145. The site is http://tcebookstore.org>.


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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