For The Answer
Express-News Weekly Column
Saturday, May 31, 2003
Submitted by Calvin Finch, Ph.D., Manager, Conservation Division, Water Resources & Conservation Department, SAWS, and Horticulturist
FOUNDATION SHRUBS AND TALLER SHRUBS
The basic foundation shrubs for a xeriscape landscape in San Antonio are hollies and nandinas. There are many different sizes from which to select, so you can place the shape and size that fits in the space available. Very little pruning has to be done and, if you select the right variety, they should never overgrow your windows or doors. Nandinas and hollies are evergreen and grow in sun or shade. The two species are largely insect and disease free. Dwarf burford holly reaches about 4 ft. tall and 3 ft. in diameter. Dwarf yaupon holly makes a disciplined globe about 2.5 feet in diameter. Compact nandinas reach about 2.5 feet tall and often have good winter color. Some of the new mid-size nandinas have interesting horizontal arranged foliage and narrow leaves. Dwarf Chinese holly makes a tight mound about 18 inches tall with a nice Kelly green color.Beyond the foundation shrubs, large shrubs make a positive addition to the landscape. Along with small trees they link shade trees to the foundation shrubs. Many of the large shrubs have blooms, berries, or foliage that contribute to the landscape. If you are interested in songbirds, hummingbirds, and butterflies, large shrubs are essential for feeding, resting, and nesting areas.
Standard yaupon holly makes a tall multi-stemmed shrub or small tree up to about 25 feet tall. It is evergreen and every year produces a crop of small berries that decorate the landscape until the waxwings and mockingbirds eat them in early spring. The off white bloom covers the plant for a short period in early spring. Yaupon hollies come in male and female versions in nature but almost all that are offered in retail nurseries are females because the berries are so desirable. Yaupon can be pruned to any shape you need in the landscape including espalier. Deer do not seem interested in eating the standard yaupon.
Another deer resistant shrub is the pomegranate. They are full of large orange-red blooms right now that are favorites of the hummingbirds. The fruit looks like an apple with a jester’s cap. Inside are small jell-covered seeds that are favorites of birds and mammals when the decorative capsule cracks open. Pomegranates are deciduous shrubs that reach 15 feet tall. They bloom and fruit best in full sun but make a vigorous shrub even in the shade.
We do not recommend dwarf pittosporum for the landscape because they are so cold sensitive, but the standard version is still a good choice if you have plenty of space. They grow 8 feet tall and just as wide in sun or shade. The bloom in March and April is very fragrant. The pure white blooms cover the plants to make a striking show. Adding to the attraction are the butterflies that seek the nectar. In my neighborhood deer do not feed on pittosporum, but that does not seem to be the case in other neighborhoods.
There are a number of viburnums from which to choose. All the selections seem to have white showy flowers in the spring followed by small blue berries in early summer. The berries do not last long because they are a favorite of many types of songbirds. Spring Bouquet, Sweet, and Sandakwa are three varieties that I have in my landscape. They grow to 8—12 feet and are thought of as shade-loving plants.
Vitex is not much interested in the shade. In full sun it makes an airy small tree or shrub 20—25 feet tall. Vitex is one of the toughest xeriscape plants available. Deer, insects, disease, and drought do not phase this shrub. As tough as it is, vitex is most known for its fragrant purple-blue bloom. Major flushes of color occur in early summer and fall, but some flowers appear throughout summer. Vitex is also known as lavender tree, chaste tree, or Mexican lilac.
The good news is that many of our best low-water-use plants such as vitex are also good butterfly plants. A low-water-use landscape is usually also a good butterfly landscape. To celebrate the complimentary nature of butterflies and low-water-use plants and the opening of the new Butterfly Exhibit at the San Antonio Zoo (July 1), the radio gardening media (Bob Webster, KTSA, Saturdays from 6—9 a.m. and Sundays from 8—11 a.m.; Orlando Martinez, WOAI, Saturdays from 10 a.m. until 1 p.m. and Sundays from 9 a.m. until noon; Jerry Parsons and Calvin Finch, KLUP, Saturdays from noon until 2 p.m. and Sundays from 1—3 p.m.; Bob Fitzimmons, KSLR, Saturdays at 3 p.m.; or Weldon Riggs, KKYX, Saturdays from 8—10 a.m.) are going to feature butterflies and butterfly plants. They are going to enlist their respective listeners in a special water conservation challenge that will benefit the participants and support the new exhibit. Tune into this column and your favorite gardening radio show to learn more.