Fern Acacia – A Native Groundcover
This has been a great summer to evaluate the toughest of plant choices for the landscape. Showy blooms are highly prized, but foliage color and texture should not be overlooked. Fern acacia (Acacia angustissima v. hirta), has enticing garden appeal from late spring until it freezes to the ground after a hard frost.
Fern acacia, a thornless species in an otherwise thorny group of plants, is found throughout much of Texas and ranges north to Missouri, east to Florida, west to Arizona, and south to Mexico. It is reported to be the most common acacia species in North-Central Texas. A perennial which spreads through woody rhizomes (underground stems), fern acacia grows to 3 feet tall in full sun to partial shade. A well-drained soil site is best, as this plant thrives on moderate to very little water. The small, fuzzy, white flowers appear intermittently from May through October, followed by reddish-brown, flattened, 3-inch seed pods. New plants are easily propagated from seed or root divisions.
The real beauty of fern acacia is in the delicate, bipinnate, green foliage which folds up at night or when disturbed. The leaflets, usually covered with very fine hairs at the leaf margins, provide a silvery glow under certain light conditions or with morning dew. This fern-like leaf texture provides a soft contrast to other broadleaf shrubs or grasses, such as smokebush, viburnum or Indiangrass. It can be utilized as a taller-growing groundcover, to provide textural foliage contrast, or as a soil stabilizer for embankments. The flowers are a good nectar source insect pollinators, and fern acacia is a host plant for several species of butterflies. The seed and pods are sometimes eaten by cattle and quail. The young foliage is protein-rich fodder for cattle, goats and horses.
At Texas Discovery Gardens at Fair Park, a one-gallon plant obtained from Benny J. Simpson has spread approximately 400 square feet in 10 years with scant supplemental watering. Fern acacia will spread more vigorously under regular irrigation, so be exact when selecting its place in the landscape. During the winter months where plants die back, the top growth can be mowed before new growth emerges in spring. Fern acacia is delicate in appearance, but tough enough for most Texas landscape situations.
About the author: Tina Dombrowski is the Director of Horticulture at Texas Discovery Gardens at Fair Park, Dallas. She has a particular interest in Texas native plants, butterflies, pollinating insects and their interconnected histories. Visit www.texasdiscoverygardens.org for more.