Accession Count: 33
Common Name:
soaptree yucca
Family Name:
Asparagaceae
Botanical Name:
Yucca elata
Sub Species:
Variety:
Forma:
Cultivar:
Characteristics:
Yucca elata is an upright, trunked, woody succulent growing from 12 to 20 feet. It frequently becomes branched with age, often extending over six to 10 feet wide, with up to seven (rarely more) branches. The species is unique among yucca with vertical rhizomes that grow downward for 3-5 feet (6). This depth provides protection from temperature fluctuations and a means to reproduce vegetatively (2) Its fibrous blue-green leaves grow in a dense head or rosette and can grow to 38 inches long and one inch wide. The leaves also have sharp, pointed ends, white margins and produces fine, stringy fibers (1,2). As the leaves age, they turn brown and create a layer of dead leaves over the stems (4). In late spring to early summer, reproductively mature plants send up a 4-6 foot flowering stalk from the center of each rosette (1,4). Large, white, bell-shaped flowers appear shortly after in loose clusters on sides of the stalk (3,4). The flowers eventually give rise to woody, 3-chambered capsules that contain about 150 windblown seeds each. Y. elata’s root system is unusual because it is composed of a rhizome that initially grows downward and then sends out lateral root extensions (5).
Compound:
Yuc ela
Geographic Origin:
Desert Southwest
Ecozone Origin:
Nearctic
Biome Origin:
Natural History:
Y. elata is found in northern Mexico and parts of southwestern United States. They are prevalent in semi-desert grasslands of the Chihuahuan Desert, and is generally found between elevations of 1,500 and 6,000 feet in Arizona (1,5).
Cultivation Notes:
Soaptree yucca can be grown from collected seed or from offsets formed on the rhizomes of established plants (3). It is very drought tolerant and cold hardy down to about 0°F (1). It requires virtually no maintenance and can survive solely on rainfall once established. Its growth rate is very low—about one inch per year—but growth can be increased somewhat by supplemental irrigation (1,3). It is tolerant of most soils as long as they are well-drained, and should be planted in full sun (3). According to Gregg Starr of Starr Nursery, if you are going to buy a soaptree yucca, be sure to purchase one that has been reestablished in a container, as "bare root" plants can have some difficulty setting out new roots (1).
Ethnobotany:
Soaptree yucca is an outstanding accent plant for any southwest garden. The scented flowers and low maintenance make it a great choice for landscapes, and is best used in transition or arid zones when using xeriscape techniques (1). Y. elata has been used for a variety of purposes. Namely, it is best known for the soap or shampoo that can be produced from its roots and trunk. The saponins in the soap, however, are poisonous and should not be ingested (3,4,5). Native Americans would consume the flower stalks and ground the inner trunk into meal (5). Flower petals and buds are edible and can be eaten cooked or raw (3,4). The fibers from the leaves have been used to make rope, baskets, sandals, clothing and other textiles (3,5). Reproduction by seed depends on a mutualistic symbiosis with the plant’s pollinator, the yucca moth (Tegeticula yuccasella). Female moths pollinate the plants as they lay eggs in the yucca flower. Once hatched, the moth larvae feed on some of the fruit, reducing the number of potential seeds. If too many of the seeds are eaten, the yucca aborts the fruits, killing the larvae. In this way, the plant and the moth maintain their relationship (5).
Height:
16 - 20 feet
Width:
6 - 10 feet
Growth Rate:
Slow Growing
Grow Season:
Summer
Flower Season:
Spring
Color:
White
Function:
Accent
Spread:
Non-spreading
Allergen:
Non-allergenic
Invasive:
Benign
Toxicity:
Benign
Hardy:
Hardy
Water Use:
Low water Use
Citations:
1. Starr, Greg. Starr Nursery. Personal Communication. & Mielke, Judy. Native Plants for Southwestern Landscapes. University of Texas Press, 1993.2. The American Southwest. -- Retrieved Oct. 26, 2018.3. Lady Bird Johnson Wildflower Center. -- Retrieved Oct. 26, 2018.4.
The Firefly Forest.
-- Retrieved Oct. 26, 2018. 5. “Yucca
elata.” Fire Effects Information System.
U.S. Department of Agriculture, Forest Service. -- Retrieved Oct. 26, 2018.
