Neil Sperry

Tree questions of a curious sort

As tree questions go, the ones I’ve assembled today don’t rank very high. But I’ll betcha they’re questions you’ve asked yourself, and they might make for a little fun reading here in mid-summer.

Will ivy growing up a tree’s trunk hurt the tree?

Not unless it reaches the top branches and forms a canopy out and over the tree. That cuts off sunlight to the tree, which is obviously detrimental.

The only other way it could be of harm would be during ice storms. Most of our shade trees are deciduous, while English ivy is not. When ice coats ivy foliage, it adds a great deal of weight to the horizontal branches, and that can cause branches that normally would not break to snap.

But ivy does not take any sustenance from the tree’s trunk or branches. It would be just as happy climbing a brick wall.

Why does bark fall off my tree in big chunks? Is there anything wrong with the tree?

That is absolutely normal. Bark is not a living tissue, so it has no means of expanding. As the tree’s trunk grows larger, all the bark can do is split and fall off. Usually, there is a new layer of bark already forming beneath it.

This is much more conspicuous with some tree species than with others. Crape myrtles and sycamores are the two most common examples locally. They lose large sheets of thin bark all spring and summer. Pecans will shed slabs in the spring.

But unless you see decay or other signs of problems when the bark falls, there is no cause for concern.

Is it true you can tell how old a tree was by counting its growth rings?

To a degree, yes. Each normal growing season will yield one growth ring.

But foresters are quick to point out that some years, there will be a strong surge of growth in spring’s rainy weather, then heat and drought may shut it all down.

If there is a second rainy season in late summer and early fall, there may actually be a second, usually less defined, growth ring.

Do roots coming to the surface beneath my tree indicate any kind of a problem? Should I cover them up?

This is like the bark sloughing off — it’s absolutely normal. Most of any tree’s roots will be near the soil surface, because that’s where the rain soaks into the soil in nature. As a tree grows larger, so will its roots, until their thickness brings them up and out of the soil.

It’s no cause for concern, and it does not imply erosion. If they’re unsafe or unsightly, plant a shade-tolerant ground cover that can conceal them, but don’t try to cover them up. That will merely make things much worse.

Should woodpeckers on my tree worry me? Are they indicative of a problem?

In the intellectual ratings of birds, woodpeckers and sapsuckers may not finish near the top. It just seems to be such a hard way to make a living. While they probably are trying to scare up their next meal, they’re as likely as not to leave your tree and move over to a creosoted telephone pole.

Sapsuckers do feed on the sap flow that occurs a day or two after they peck their holes, so they do some limited damage. Both birds are protected by law, however, so all you can do is discourage them.

I protect my vulnerable trees with paper tree wrap or Tree Tanglefoot (an obnoxiously gooey material I can put on the trunks and branches of my trees). But I seldom have to do so.

Why do some of my trees start losing leaves by early July?

This usually happens to large-leafed, fast-growing trees like catalpas, cottonwoods, fruitless mulberries and silver maples. Cool, wet spring weather encourages rampant growth in these trees. They come to in mid-summer’s heat and usual drought, only to realize they have overestimated their ability to sustain all those leaves. They’ll start shedding them by early July, and it will continue until frost.

You can water them deeply to help lessen the impact, but they’re still going to do it. You’ll notice that it’s usually the oldest leaves (those nearer the trunk).

When I feed and water my trees, are the root-feeding rods a good way to do so?

My answer here goes back to the fact that 90 percent of any tree’s roots are going to be in the top foot of soil. If you use the rods, you’re going to bypass that huge part of the root system, plus it’s going to take you hours and hours to move the rods around within each tree’s drip line.

Surface applications of a lawn-type fertilizer and sprinkler or soaker hose irrigation are your best solutions.

When I water my trees in hot weather, are the bags of water around the trunks good?

For first-year trees, perhaps, but a berm of the soil you removed as you dug the planting hole is a lot less expensive, and it serves just as well (if not better).

Use the garden hose to fill the basin every few days for the first couple of summers. If you use the bags with older trees, you’ll be missing all those roots that are now fanning out away from the trunk beneath the trees’ drip lines.

As a tree grows, the roots that are active in taking in water are no longer near the base of the trunk. This is not a reliable or cost-effective way for home gardeners to water their trees.

Neil Sperry publishes Gardens magazine and hosts “Texas Gardening” from 8 to 10 a.m. Sundays on WBAP/820 AM. Reach him during those hours at 800-288-9227. Online: http://neilsperry.com.

  Comments