Reliable Summer Color...Tecoma stans, Esperanza ("Yellow Bells")
Every year at this time we realize the value of truly heat- and drought-tolerant plants. Esperanza is also known as "Yellow Bells" and is limited only by its ability to withstand cold. It is normally root hardy through Zone 8 and grown in containers farther north. Cold tolerance varies and it is reliably hardy only in Zone 9 and south. Winters like this past one have tested them but my two plants in College Station returned from their roots by late May and were blooming well by July 1. They do have some protection from a low retaining wall just northwest of their root zones.
Yellow Bells (Tecoma stans)
Heat and drought tolerance is where they truly excel. Flowers are most prolific during July and August when temperatures are at their peaks. Twelve to fifteen inch clusters of 3-4' bell shaped flowers are really bright yellow. In areas where frost occurs cut the plants back during late winter near ground level. If they don't freeze in your area prune and shape them in late winter. Esperanza does not perform well in the shade or in poorly drained soils. Little or no irrigation is required once the plants are established. It appears that more sun and heat produces more flowers. Seedpods are sometimes produced and seedlings may appear near your plants. Cuttings taken during the growing season are the way commercial growers produce more plants.
There are orange flowered types that tend to get larger and tolerate more cold than the commonly available yellow form. Like hardy hibiscus, Yellow Bells combine nicely with large growing crinums and spider lilies (Hymenocallis liriosme). The plants have a naturally graceful appearance. Rain lilies such as Habranthus robustus can be massed in front but keep in mind the ultimate large size of the Yellow Bells (6-7'). Lantana is another good, heat tolerant plant with the trailing purple form (Lantana sellowiana) making a beautiful combination.
All these plants need to be cut back in late fall or winter making room for narcissus and leucojum that fill in nicely during late winter and early spring. By the time the roliage starts to dry up on the narcissus and leucojum the Yellow Bells, lantana and Hardy Hibiscus are beginning to start activity.