For The Answer
WILSON COUNTY NEWS
Calvin R. Finch, Ph.D., Conservation Director and Horticulturist, San Antonio Water System
Week of March 15, 2004
Q. I know what Texas mountain laurel is but there are some other plants that are blooming now that I would like for you to identify for me.
One is a vine with rusty colored tubular flowers. It seems to be growing in full sun. Another plant has beautiful yellow blooms on stalks above mounding light green foliage that looks like maidenhair fern. The third plant has dark green foliage that grows in a weeping shape in 12-foot circles. It has small waxy yellow blooms.
A. The vine you describe is probably cross vine. It is an evergreen vine for full sun that is aggressive enough to block an unattractive view but will not take over the neighborhood. “Tangerine Beauty” is the best selection.
The groundcover with yellow blooms is “Texas Gold” columbine, an outstanding perennial for South Texas. It makes a beautiful groundcover under pecans and other deciduous trees. It can tolerate winter sun but needs summer shade.
My guess on the third plant is primrose jasmine. It is a tough xeriscape plant that the deer will not eat. Use it in full sun.
Q. My lawn looks great because it is covered with a weed grass. Will it hurt my St. Augustine grass? Do I need to kill it?
A. The weed is probably rescue grass, a cool-weather annual weed. Annual bluegrass and rye also would fit the description. Any weeds stress the lawn grasses, so it is best if they are brought under control. Next year, in September, apply a pre-emergent herbicide like Amaze, Balan, or Betasan to prevent it from returning. For now just keep it mowed to prevent reseeding. I have to admit that a winter lawn of rescue grass looks better than my St. Augustine grass in the summer and I do not control it myself. If you have poor soil and excessive shade it is not unusual for the St. Augustine grass to be so thin that the weed grasses take over in the winter.
Q. When should we fertilize our grass?
A. Wait until the end of April or in early May. Fertilizer applied now only benefits the winter weeds. Our hot weather grasses need warmer soil to utilize nitrogen fertilizer. The best time is after you have mowed “real” grass twice.