Q. Bermuda grass is taking over my flower garden. Should I have used a preemergent herbicide to prevent it? The grass is so hard to pull up, what is a possible treatment?
A. The easiest treatment is to apply one of the contact herbicides for grass. The products include Over-the-Top, Fusilade, Poast, Ornamec, and Grass-be-Gone. Read the label at your favorite nursery to find out what is the best product for your purposes but all of them can be sprayed on Bermuda grass in the midst of flowers and shrubs without hurting the non-grass plants. The herbicide is applied to the green vegetation of the grass and is translocated to the roots to kill the whole plant. Follow label instructions.
Q. We planted a vitex a few weeks ago and it has finished blooming. Should we prune off the seeds to encourage more bloom?
A. Yes, prune off the developing seed and you should get more bloom. Another management option is to prune pack the whole plant this winter so it will only grow to about 6 feet tall every summer like an esperanza or Pride of Barbados. Another advantage of pruning off the seed is that none is available for unwanted vitex seedlings.
Q. My summer squash was looking great until this last hot dry spell. It wilted. I watered it but it did not respond. When I examined the stalk, it looks like some rat or insect chewed and hollowed it out. Any ideas what it is and how to treat it?
A. I believe you are experiencing squash vine borer damage. Summer squash is very susceptible. Pull the damaged plants. If you plant summer squash again this fall, try to control the borers by spraying or dusting the growing point with Sevin or malathion every week. Another option to consider is to plant tatuma (Mexican) squash instead. It produces round shaped fruit that can be used just like crookneck summer squash. Tatuma does not seem to be susceptible to the vine borers.
Q. What happens if we let our zinnias reseed? We love the lesser goldfinches and noticed that they feed on the seed produced by our sunflowers and zinnias. The sunflowers aren’t reseeding this summer, but new zinnias are coming up. Can we just let the new seedlings bloom?
A. Yes, the new seedlings may not match the original flowers if they were hybrids from the nursery, but they will be almost as attractive and even more popular with the hummingbirds, butterflies, and bees as a nectar source. The sunflowers in my yard reseed every year but just like yours don’t produce a second crop each summer.
Q. We need a shade tree. What is our best choice? Can we plant it now?
A. The recommended shade trees include Texas red oak, cedar elm, Mexican sycamore, live oak, bur oak, Mexican white oak, and chinkapin oak. Texas red oak is my favorite because it is attractive, grows fast, and is drought tolerant. Shade trees can be planted now if you water them every week through the first summer.