Host Trees

Host Plant in Sandalwood Farming

Why does Sandalwood need a host tree?

Sandalwood trees are root hemi-parasites and require host trees for healthy growth. The host trees provide extra water and nutrients to the sandalwood delivered by a unique root connection called haustoria. The two trees form a symbiotic relationship throughout the life of the sandalwood tree. The best host species are the nitrogen-fixing plants.

Sandalwood seed is large with a dense store of carbohydrates that drive the rapid root growth required as the seedling searches for the roots of a host. If the tree cannot fix onto a host within one or two years it will die. With the host plants already established the simplest and most cost-effective method of establishing the sandalwood is to direct sow treated seed close to the host.

Germinating Sandalwood seed showing the vigorous root system that develops in search of a host plant

Researchers suggest aiming for about 500 Sandalwood trees per hectare. If the host is a one-year-old wattle the seed should be planted within a metre. For more established trees it may be worth exploring how far the roots of the hosts extend before sowing the seeds. Planting the Sandalwood on the north side might be a way of reducing the shading.

Emerging Sandalwood seedling (foreground) beside a host plant (native wattle) that was planted prior to sowing of the seed