For The Answer
Submitted by Calvin Finch, Ph.D., Manager, Conservation Division, Water Resources & Conservation Department, SAWS, and Horticulturist
SUMMER COLOR PLANTS
The summer color plants are available at the nurseries.
Periwinkles (vincas) come in white, several shades of lavender, and a few red-pinks. Many have white or colored eyes in the center of the flower. There are several varieties. Some are as short as 8-to-10 inches and others as tall as 30 inches. Use periwinkles in full sun. They make excellent container plants. As bedding plants, use them in open gardens with plenty of air movement. Periwinkles are annual flowers but they qualify as xeriscape plants. After they are established one watering or rain per month will keep them alive and a watering every two weeks is all that is required for maximum bloom. Water periwinkles at the base rather than wetting the foliage if it is possible. Use mulch to keep soil from splashing the plants but do not let it get soggy. Periwinkle is susceptible to aerial phytophera, a melting disease that thrives in damp situations.
Lantanas come in many versions and colors. Popcorn is a mounding variety with an off-white color. New Gold is an aggressive spreader. Samantha has a light green leaf with some variegation and a lemon-yellow flower. It mounds but is more upright than Popcorn. Spreading lavender is less aggressive than New Gold that makes a very low groundcover. It also comes in white.
There are several upright lantanas as well that offer bicolor flowers including pink and white, yellow and white, and carmine and orange. The upright selections often produce berries that are sought by the birds. Lantana blooms are a favorite of hummingbirds and butterflies. Deer in most situations pass up the plants. Use most lantanas in full sun. The lavender does seem to tolerate some shade. Water lantanas about the same frequency as periwinkles for good bloom performance.
Moss roses (portulaca) and purslane are very similar in appearance and growth habit. They are 2-to-6 inches tall and spread to 12 inches. The purslane foliage is mouse-ear shaped and the moss rose foliage is torpedo shaped. Both have the appearance of a succulent and perform like one. Moss rose and purslane are annual flowers for full sun that can tolerate heat and limited water. Moss rose has a compound flower; purslane is a simpler bloom. The blooms are about quarter size. Moss rose produces a large selection of rich pastel colors and purslane are more basic. Red, pink, yellow, white, and orange flowers are available. Purslane and moss rose have a mutual flaw, they are day bloomers. If you work 8 a.m. to 5 p.m. you will have to wait until the weekend to enjoy the rich blooms. The wait is worth it. The moss roses and purslanes are especially desirable as container plants.
Esperanza (Texas Bells) is another hot weather bloomer. In many neighborhoods deer do not eat the lush green foliage or yellow tubular flowers. On most sites it is a root hardy perennial that reaches 5 or 6 feet in the summer after freezing back in the winter. In sheltered locations esperanza grows to a small tree. Regular visitors to the Botanical Garden remember the plant as part of the triumverate of firebush (red blooms), poinciana (orange blooms) and esperanza that blooms in the island of the parking lot all summer through the droughtiest times.
Take advantage of the relatively mild days of early June to plant these hot weather bloomers. All the rest of the summer you will enjoy the color without excessive water.