Yucca Brevifolia Data Sheet

• Common names: Joshua tree

• Latin name: Yucca Brevifolia

• Genus: Yucca

• Height: 15 m (49 ft)

• Type: Evergreen

• Hardiness: Zone 7

• Conservation status: Threatened

Yucca Brevifolia is often referred to as the Joshua tree. The leaves are dark green and bayonet-shaped, reaching a length of 35 cm and a width of 1.5 cm broad towards the trunk. The tips of the leaves taper into an impressively sharp spike. The flower stems are around 50 cm long with creamy white, tinged with green colour. When a flower stem develops, the plant will often branch at the point where the flower stem appears.

Yucca Brevifolia is native to the southern states of the U.S, including Nevada, Utah, California and Arizona. This species is frost hardy and a good freeze will encourage flowering in the spring. Caution should be used when planting as this tree has an extensive root system.

Pregermination

These seeds need no pretreatment as such. Germination time can be reduced by soaking the black seeds in water for 24 hours to soften the hard shell prior to sowing. Once soaked, fill trays or pots with quality compost and firm down gently. Spread seeds across the surface; around 10 in a 10 cm pot is ideal. Cover with 3 mm of compost and gently firm down.

Compost should be kept damp, not soaking wet or dried out. A temperature of between 60F and 70F is perfect for yucca germination. Place pots or trays on a cool to warm windowsill or in a cool conservatory. Germination should occur at 1–3 weeks, depending on the soaking process, germination can take up to 8 weeks.

Post Germination

Keep seedlings in a bright, well-ventilated area to reduce the risk of damping off disease; a windowsill is ideal. Ensure they don't dry out or become waterlogged. These seedlings will quickly develop a large root system. They can be separated into 4" pots at 15–20 weeks; by this stage they are frost hardy and can stay outside all year. Fertilization is not required up to this point. During spring and summer we advise using an NPK 10-10-10 fertilizer every 4 weeks.