June 11, 2105:

Tell us again about the two-step strategy to control fire ants. They seem to be especially visible and vicious this year.   Fire ant populations increase when plenty of moisture is available in the landscape. Wet soils also force them to build more visible mounds. The two-step control method calls for the use of a fast-acting insecticide such as acephate on the mounds close to human activities and a slower acting bait spread thinly over the rest of the landscape. Amdro is often the choice for the  bait spread over the yard. Acephate kills ants on mounds to which it is applied within a few minutes. The baits often take up to 2 weeks to destroy mounds.

Products with the organic product spinosad (Conserve) can also be used for both the direct treatment of mounds and in bait products. Some products with spinosad are labeled to allow that they can be used directly in the vegetable garden.

Is it a good time to prune the old blackberry canes or should we wait until closer to spring? The earlier that you can prune out the seasons old canes( floricanes) to make room for the new canes (primocanes) the better it is for next year’s production. Removing the spent canes also reduces the scratches caused to gardeners by the old canes.

We have purchased a new home. The neighborhood is blessed with plenty of hungry deer. Where can we find a good deer-proof plant list? . Among the plants listed will be Texas mountain laurel, esperanza, thyrallis, yaupon holly, Mexican honeysuckle, Mexican oregano, society garlic, iris, butterfly vine, lantana, salvia, and four-o-clocks.

 Which lawn grass has the most shade tolerance?  Is it also drought tolerant? St Augustine grass has the most shade tolerance. Floratam, one of the St Augustine selections did well in drought tolerance tests in San Antonio, but most St Augustine varieties are not drought tolerant.  Bermuda grass the most drought tolerant of the popular grass selections has very little shade tolerance. For drought tolerance and shade tolerance consider switching from lawn grass to one of the other groundcovers.  Asiatic jasmine, dwarf ruellia, and monkey grass all have excellent shade tolerance  plus require less water than the lawn grasses. For extensive information on alternatives to lawn grasses visit my archived articles on plantanswers.com or the San Antonio Water System website, www.saws.org and click conservation.

We have had problems with mildew on our zinnias and aerial phytophera on our vinca. My guess is that it is the rainy cool weather. Can we just replant or do we need to use some other flowers this summer?  I recommend that you replant but make sure you use the disease resistant selections such as Dreamland zinnias and Cora vinca.

Dr. Calvin Finch is Urban Water Program Director for the Texas A&M Institute of Renewable Natural Resources.
You can ask Calvin question and hear his answers on the air as he co-hosts the Gardening South Texas on the air at KLUP (AM 930) Saturday and Sunday from 12:00 to 2:00pm.