For The Answer
Saturday, August 10, 2002
Submitted by Calvin Finch, Ph.D., Manager, Conservation Division, Water Resources & Conservation Department, SAWS, and Horticulturist
Crepe myrtles responded well to the rains and cool weather in July. Most of them put a flush of bloom on that was spectacular for three weeks. Many have now lost their bloom. If your plants are short, removing the seedheads will encourage another flush of bloom later this fall. We have had a number of reports that crepe myrtles were showing reddish small leaves. Often, these are newly planted crepe myrtles or containerized crepe myrtles. The symptom usually indicates stress due to nutrient deficiency. Root damage from soggy soil might be the problem, or just a nitrogen deficiency because the flush of growth and rain leached all the available nutrients.
The trick is to determine which situation is occurring: if the roots are injured, fertilizer may injure them further; if the soil was soggy or there was standing water over the root system, let the plant repair itself; if the plant bloomed well before the symptom appeared and the soil is well drained, add one cup of lawn fertilizer; if the crepe myrtle is in a container, use a soluble fertilizer like Peters or Miracle Grow.
Poinciana (Pride of Barbados) is also blooming now. The glow-in-the-dark orange and red flowers are spectacular. This plant is very drought resistant so we were not sure that it would fare well with 25 inches of rain and cool weather but it certainly did. Look for poinciana to continue to bloom until late fall arrives if the hot, dry weather continues. Retail nurseries seem to have a good supply of poincianas now. It is a good butterfly and hummingbird plant but the deer eat it.
Another drought-resistant blooming plant that seemed to survive the floods well is Texas bells (esperanza). It has light green foliage and yellow blooms. Deer do not eat Texas bells in most neighborhoods. Remove the seedpods as they appear to prolong the bloom, otherwise, it is a cyclical bloomer.
A few periwinkles became infected with aerial phytophera during the prolonged rains but, as soon as things dried out, the plants that escaped the disease resumed blooming. They are looking good in many beds. In my cut flower bed the white flowered periwinkle that I used as fillers last summer reseeded and look very good. Periwinkle is not eaten by deer in my neighborhood.
Zinnias loved the rain but are picking up the usual dose of powdery mildew now. Deadhead the healthy plants to keep them blooming. Expect reseeded zinnias to germinate after the next rain we receive. They are usually not as colorful or compact as the hybrid transplants, but the butterflies like them better and they make a good show until cold weather arrives. It is a good time to plant zinnias for the fall. Deer do not like zinnias.
This has been the best summer I can remember for society garlic. It blooms well every spring but flowering declines in the heat of summer. Not so in 2002. It loved the wet, relatively cool July and is still blooming. Society garlic has a lavender-colored bloom on a stalk about 18 inches tall above the onion-like foliage. It grows in clumps that become a pretty good ground cover even in light shade. Society garlic is also not usually eaten by the deer.
Sunflowers have done well all summer. They make good cut flowers and the birds love the seeds. Lesser goldfinches, cardinals, and blue jays are especially noticeable pulling the seeds from the heads. They are not the only colorful animals feeding on the sunflowers. The banded sunflower moth caterpillars are feasting on the foliage. One visitor to our radio broadcast at Milbergers brought in a jar of the caterpillars in their blue phase. Last weekend the larva on my sunflowers were orange. They are one of the showiest caterpillars around.
Live oaks are not blooming now but a few trees around Central Texas have been blessed with rust, a fungus disease. Sometimes, the disease causes complete defoliation. Look at the leaves; the rust symptom is pretty obvious: red, rusty pistules on the underside of the leaf and yellow shadows on the top. The disease does not cause any long-term damage. There is no good treatment.