By Bill Ward
Published in The Boerne Star on October 5, 2007
Operation NICE! (Natives Instead of Common Exotics!) recommended plant for October is western soapberry (Sapindus saponaria var. drummondii). This small- to medium-sized tree is common throughout much of Texas, yet it seems to me that few people think of soapberry as a landscape plant in Hill Country yards. However, it is a good-looking, drought-tolerant little tree with nice fall color.
One thing I like about western soapberry is that it is the native-plant answer to chinaberry (Melia azedarach), the exotic tree that has extensively invaded many riparian habitats in this area. Even though the chinaberry is high on all lists of the most notorious invasive alien plants in Texas, it is still planted in some places. The native western soapberry would be a wiser choice for landscaping.
Soapberry, like chinaberry, has foliage that gives it a somewhat airy aspect, but the leaves are not similar. The yellow-green soapberry leaves are pinnately compound with 4-19 lance-shaped leaflets a few inches long, somewhat resembling our native walnut. Chinaberry leaves are darker green and bipinnately compound with small leaflets that have toothed margins.
In the field, I commonly mistake soapberry for flame-leaf sumac, but soapberry has alternate leaves and leaflets, while sumac has alternate leaves with opposite leaflets and flanged stems. In addition, it seems to me, the soapberry much more commonly lacks the terminal leaflet than does the flame-leaf sumac, but I haven’t found that in the books. Unfortunately, I can’t figure out how to distinguish soapberry leaves from those of the exotic Chinese pistachio (Pistacia chinensis).
During late spring to summer, western soapberry has clusters of creamy white flowers. On the female trees the blooms are followed by marbled-sized fruit. Another similarity between western soapberry and chinaberry is that both have small round drupes that commonly dry and remain on the tree after the leaves are lost in the winter. The mature fruit of the chinaberry is opaque dull-yellow, but mature soapberry fruit has a black seed surrounded by a translucent amber-colored jacket.
The fruit of the soapberry contains a high percentage of saponin, which made it useful as a soap substitute for Indians and pioneers. Supposedly this toxic fruit also is used to stun fish in some places in Mexico. According to Sally Wasowski (“Native Texas Plants, Landscaping Region by Region”), the soapberry fruit may be poisonous to many animals, but bluebirds love it.
Soapberry grows in a variety of soils in part shade to full sun. Apparently, it prefers good drainage, but our soapberry suffered less than some our other native trees during the heavy rains this summer. As a landscape plant, this tree grows moderately fast. In this part of the Hill Country, soapberry usually will not reach more than about 25-30 feet tall. Soapberry may not be suited for planting in lawns, because it might send up suckers. However, it is a good medium-sized tree for the periphery of yards or along roadsides.
The Boerne Chapter of the Native Plant Society of Texas provides free planting and care instructions for western soapberry at nurseries participating in Operation NICE! (Hill Country African Violets and Nursery, Barkley’s Nursery Center, and Maldonado Landscape and Nursery).
A notable and desirable attribute of soapberry is the fall foliage of lemon-yellow, gold, and orange. Even though one of the common names for S. saponaria is wild chinaberry, the soapberry is much prettier in the fall than the common exotic chinaberry.
Pull up a chinaberry today and plant a soapberry!
