Jade tree (Crassula arborescens) is an architecturally interesting succulent plant from the arid, frost-free lands of southern Africa. Its fleshy, attractive light blue-green to whitish blue leaves distinguish it from the common house plant, jade plant, which has deep green foliage. Lots of sunlight, heat and a coarse, well-draining soil is needed for this plant to prosper.
The jade tree, also commonly called the tree crassula or silver jade plant, is a succulent stumpy tree of the stonecrop family, Crassulaceae. Jade tree's scientific name is Crassula arborsecens.
This species is sometimes confused with Crassula ovata, jade plant or Japanese rubber-tree, which is much more widely used as a house plant and has emerald green foliage.
Jade tree is native to southern Africa, in the nations of South Africa and Swaziland, with two subspecies extant. Crassula arborescens subsp. arborescens is native from the Hex River Valley to the Little Karoo and then further north as far as KwaZulu-Natal and Swaziland. Crassula arborescens subsp. undulatifolia is found in the southern parts of the Klein Winterhoek Mountains of the Eastern Cape.
Both types of jade tree grow in sunny, exposed sites in rocky, gravelly soils that have little fertility.
Smooth, gray-green bark covers this single-trunked plant that sports many branches. It has powdery blue-green leaves that are fleshy and waxy, round in shape with a sharp tip. The leaf edges are blushed thinly in red.
In spring to summer the plant is covered in thousands of tiny, star-like whitish pink flowers. The flowers dry to attractive pale tan and persist as the dry, oval fruits split open and release tiny seeds into the wind.
At maturity this small tree can grow as tall as 10 feet.
A average to nutrient-poor soil that is fast-draining and comprised of grit, gravel or sand is needed. Full sun exposures, a minimum of 8 hours of daily direct sunlight is best and accentuates the bluish white color in the leaves.
It is hardy in USDA hardiness zones 9 through 12, and should not be exposed to freezing temperatures, which will rupture the watery tissues in the trunk, leaves and stems. A light frost may be tolerated without any damage.
In arid tropical regions, the jade tree can be grown outdoors in the garden as a focal specimen plant in a rock garden, building foundation bed or mixed plant border. In regions that experience cold, frosty winters, jade tree can be grown as a house plant when small and young, receiving very bright light or as much direct sunlight in a warm to hot windowsill or sunroom.