IN THE GARDEN: Gummosis is cherry tree's response to damage, likely from pests

The ball of hardened sap emerging from this cherry tree looks like gummosis, a protective response to a boring insect. (Special to the Democrat-Gazette)

Q: These hard clear bubbles have formed from secretions from a few of my wild cherry trees. [The reader sent photos.] Do you think it is heat related or an indication of pending tree doom? Do other readers have similar experiences?

A: The clear bubbles you are seeing on your black cherry are called gummosis — a response in many fruiting trees to any wound or disturbance. Since it is small and round, I would assume it is a response to a boring insect. Any wound or opening on the bark of a cherry tree can prompt the appearance of gummosis. On a healthy tree, it actually pushes the insect out and can prevent further damage. If you see only a few "bubbles" and the tree is fully leafed out, I would say you are fine. There is not much you can do about boring insects on large trees, but the healthier and happier the tree, the less damage you should see.

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Q: This picture is a small portion of my zoysia lawn. The damage is approximately 18 inches wide in a horseshoe half-circle that spans over 30 feet wide. It's the second one that we've had; but they have occurred in different parts of the zoysia lawn. Any ideas on what might cause this? Any way to cure or stop this?

A: My guess is "large patch disease" of zoysia, a fungal disease; but there are several diseases that can affect zoysia lawns. You can take a sample in to your local county extension office. The best sample would be from a transition zone — an area with some good and bad turf, including roots and a little soil. The disease lab can culture out the disease, tell you for sure what it is and give you possible remedies. Here is the extension fact sheet on large patch disease:

Q: I have some large bare spots in my front yard. I'd like to know what kind of grass seed I can put down. As you can see, it's mostly weeds anyway [the reader sent a photo]. Thank you for your help.

A: Starting a warm season lawn such as Bermuda or zoysia from seed this late in the season won't produce promising, long-lasting results, but they are the best grass choices for full sun in Arkansas. You could get some sod pieces, cut them up and plug them into the holes and let them get growing. As you mentioned, the "lawn" does look like a great deal of weeds and not a whole lot of lawn grasses. If you plan to renovate the whole yard next year, you could throw out some ryegrass seed now to give you a temporary lawn until next spring and then start over.

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Q: Recently, one of our big trees has been [turning] a funny yellow-looking color ... like it is dying. We started watering it more, thinking it was dry, but the tree to the left of it is perfect. I was thinking that you had addressed this issue before, but was unable to locate [the column]. Please see my picture; and any help would be appreciated.

A: I am guessing, from the appearance, that this is a Green Giant arborvitae tree. We saw many of these trees/shrubs succumb to problems during the extreme heat and drought in July. While many people think arborvitae plants are like junipers, which are drought tolerant, they are not happy campers in hot, dry conditions. I did see some that were attacked by bagworms, and that did cause damage; but my guess is that your tree's trouble is weather related, and it will not bounce back. Although I am sure it doesn't make you feel better, you aren't alone with this problem.

Retired after 38 years with the University of Arkansas Cooperative Extension Service, Janet Carson ranks among Arkansas' best known horticulture experts. Her blog is at Write to her at P.O. Box 2221, Little Rock, AR 72203 or email