For The Answer
Express-News Weekly Column
Saturday, May 26, 2001
Submitted by Calvin Finch, Ph.D., Director of Conservation, SAWS, and Horticulturist
In San Antonio we receive lots of 100-degree F. days and streaks of drought that can make summer unpleasant. One of the things that helps us tolerate the weather, however, is shade. We are blessed with an extensive urban forest dominated by live oaks, pecans, red oaks, cedar elms, hackberries, and other species of trees.
Shade is desirable for relief from the sun, but it does limit our choice of understory plants. The palette of well-adapted plants for the shade is less than the list available for the sun, but there is a surprisingly good selection.
Blue plumbago is a root hardy perennial that will produce quarter-size blue blooms all summer long and even into the winter if the weather stays mild. The plant is not a disciplined grower; it will reach 3 feet tall and likes to spread. The foliage is an attractive light-green color. The ideal conditions for plumbago seem to be morning sun or speckled shade but it will grow in more or less light. The denser the shade, the fewer the flowers. Butterflies like plumbago, unfortunately, so do the deer.
Turks cap prospers in the same light conditions as plumbago with perhaps a little more tolerance for shade. There are two selections. The large flowered version (quarter size) grows to 7 feet tall at the Schultze House near in HemisFair Park. The smaller flowered selection seems to stay around 3 feet tall. Turks cap, with its scarlet red blooms and nearly evergreen foliage, makes a good rambling groundcover under oaks on poor soils. Hummingbirds love Turks cap and the deer are not very fond of it as a food.
Shrimp plant is most known for its rust-red blooms, but it also is available in salmon, yellow and several shades of red. The plant blooms in sun or shade and, like Turks cap, is not a favorite deer food. During early spring and through mild winters shrimp plant thickets (3 to 4 feet) are excellent places to find migrating hummingbirds.
There is a large selection of gingers and many of them bloom in the shade. Most have a tropical look that fits well with loquat in the shade garden.
I grew hidden ginger in my garden. It died back to the ground every winter but produced lush banana-like foliage that reached 3 feet tall every spring and, after the second year, it blooms low on stalks before the leaf stalk hides it. Butterfly ginger reaches about 5 feet tall with white or pink flowers. Other gingers have yellow flowers. The variegated ginger rarely blooms, but the yellow striped foliage is very striking. Gingers do not seem to be deer favorites. All of the varieties are interesting.
Firespike is a serious shade plant. It will have red blooms on long stalks in deep shade. It is a hummingbird favorite whether grown in a container or in the landscape. The foliage is so lush and shiny that some people use it for an indoor foliage plant. Hummingbirds love the red blooms but deer also like the foliage, so it will have to be protected from the deer.
Dwarf ruellia, Asiatic jasmine, English ivy, and monkey grass all make good groundcovers for the shade. The more sun dwarf ruellia receives, the more it blooms, but the foliage will reach 1-foot tall and cover lots of ground even in deep shade. Katy is a blue flowering version and Bonita is a pink flowering version. Deer will eat both monkey grass and dwarf ruellia in a drought but are not fond of it. Asiatic jasmine is not usually eaten by the deer. English ivy will cover the ground in one season, even if rooted cuttings are planted on 1-foot centers, but it is a deer favorite.