Haloxylon ammodendron Seeds | Saxaul

Jointed green stems and fissured bark of Saxaul (Haloxylon ammodendron) on a sand dune — Saxaul (*Haloxylon ammodendron*): Amaranthaceae, the sand-binding tree of the Gobi and the Central Asian deserts.

LATIN NAME: Haloxylon ammodendron

COMMON NAME: Saxaul

Plant Profile

Saxaul is a desert tree of the Gobi, the Taklamakan and the deserts of Central Asia, and it looks less like a tree than a bundle of green sticks. It grows two to seven metres tall, with jointed, photosynthetic stems that carry only tiny scale leaves, and bark that is grey and deeply fissured on old trunks.

The wood is extraordinarily dense and burns with a hot, clean flame, which is both its value and its problem. In spring it carries small yellow-green flowers, and in autumn the winged fruits dry on the branches and are blown across the sand.

Science & Biotechnology

The species is a model for desert plant physiology. Its taproot can reach water more than ten metres down, and its stems store salt that is expelled through the bark, which lets it grow in soils too saline for most plants.

Research in China has measured its role in fixing dunes along the Tarim and Hexi corridors, and seedlings are raised in nurseries for shelterbelt planting. Studies of its water use show that it survives on groundwater rather than rainfall, which is why it disappears when the water table falls.

Uses & Benefits

Saxaul is the main fuelwood of the Gobi, and the charcoal it makes is hot and long-lasting, which is why wild stands have been cut back across much of their range. It is planted in sand-control projects, where its roots bind dunes and its canopy shelters the soil.

Its roots are also the host of Cistanche deserticola, the parasitic plant sold as rou cong rong, and the parasite is now grown deliberately on saxaul in Ningxia and Inner Mongolia. In cultivation it is a curiosity for dry gardens and for educational collections rather than a border plant.

Cutting saxaul for charcoal is now regulated in parts of China, where plantations have replaced the wild stands that were stripped in the twentieth century. The wood is so dense that it sinks in water, and a single trunk can fuel a stove for a week. Its value as a nurse plant for other desert species is another reason it is protected.

Growing from Seed

Seed is short-lived and germinates best fresh, sown on damp sand at 20-25C with light. Seedlings are extremely slow and need deep pots, since the taproot runs down before the shoot appears.

Plant out on sand or gravel in full sun, with no added organic matter, and water only until the root reaches groundwater. The species resents humidity and rich soil, and it will not tolerate a wet winter. In its native range seed is sown in autumn into nursery beds, and the seedlings are lifted after two years, when the taproot is long enough to follow the water down.

Our Take

A tree for the desert and for the long view, more interesting for what it survives than for how it looks. Grow it where sand, salt and drought are the problem.

Herb Seeds