Yucca brevifolia, commonly known as the Joshua tree, is a large, slow-growing, evergreen, tree form yucca native only to the Mojave Desert of the southwestern United States. It is found growing at elevations between 1,600-7,200' on open, rocky grasslands where they visually dominate the landscape. Mature individuals usually reach around 15-30' tall (sometimes to 50' or more) with an open, rounded canopy of equal width. The average lifespan of a Joshua tree is estimated at 150 years, but older trees exceeding 300 years old have been recorded. Younger plants lack the distinctive branching of older specimens. The stiff, narrow, tapered leaves (between 6-14" long and 0.25-0.5" wide) have terminal spines and small serrations along the margins. The foliage forms rosettes on the ends of the branches, and desiccated leaves remain on the plant covering the trunk and stems. The creamy white, round to ovate flowers (up to 2" long and 1" wide) are borne on terminal panicles (up to 20" long). Light green seedpods (up to 4" long) mature on the tree in clusters. In their native habitat, Joshua trees are an important source of food and shelter for wildlife. Many birds utilize the branches for nesting and perching. These include cactus wrens, northern flickers, and American kestrels. A single moth species called the yucca moth pollinates the flowers. Small mammals such as antelope squirrels and kangaroo rats eat the seeds. Joshua trees were also used by the Cahullia people of inland southern California as a source of food and fibers.
According to commonly held legend, the name Joshua tree was given by Mormon settlers and refers to the biblical tale of Joshua guiding the Israelites in the battle for Ai with an outstretched arm. Uses. Suitable for desert gardens, xeriscaping, rock gardens, and other dry sites. Makes for an excellent specimen piece. When purchasing seeds or plants, communicate with the supplier and verify that they were sourced responsibly and not collected from vulnerable, wild populations.
Best grown in dry, coarse, well-draining soils in full sun. In the wild this plant thrives in extreme desert conditions, with 3-14" of annual precipitation, summer high temperatures around 120°F and winter low temperatures of -13°F. For these reasons, supplemental watering should only be supplied during prolonged drought conditions, and should be limited to one thorough soaking per month. Hardy in Zones 6-10.
Growing Instructions for the Joshua Tree
- Soak the seed in water for several hours. 2. The seeds like moist, well-drained soil. Fill a pot with asterile, soilless seed starting mix. Water the mixture so that it is moist but not wet. 3. Put the seeds on the soil. 4. Cover the seeds with a thin layer of soil that is 1/8 inch thick. 5. Water the seeds. 6. Place the pots in an area with of 70 degrees or above and in part shade. The seeds take 2 weeks to a month to germinate. 7. When the seedlings are a few inches tall, they can be transplanted.