Simmondsia chinensis Seeds | Jojoba
LATIN NAME: Simmondsia chinensis
COMMON NAME: Jojoba, Goat Nut, Deer Nut
Plant Profile
Jojoba is an evergreen, dioecious shrub of the hot deserts of the American south-west, growing slowly into a dense, many-stemmed bush with grey-green leaves and a deep taproot. Individual plants are long-lived, and stands in the wild include old, gnarled specimens that have survived decades of drought. The species tolerates extreme heat, high soil salinity and soils of very high pH, and it survives on rainfall alone once established. Nothing about it looks like an oilseed crop, which is exactly why the discovery of its seed chemistry caused such a stir.
Jojoba carries male and female flowers on separate plants, and until a bush flowers for the first time there is no way to tell which it is. Flower clusters are small, greenish and wind-pollinated, with no petals worth mentioning. Since only the female plants bear the seed, a plantation needs a small proportion of males for pollination, and a field that turns out to be mostly male is a commercial disaster. This single fact drives most jojoba breeding: growers plant rooted cuttings from selected female clones so that every plant in a row is a known producer, and researchers look for molecular markers that reveal sex from a leaf sample.
Because sex is unknown until flowering, commercial fields are usually established from cuttings taken from female plants that have already proved productive. Cuttings root best from semi-hard wood collected in the cool season, treated with a rooting hormone and kept under mist in a coarse, well-drained medium; rooting is slow and uneven in some clones. Micropropagation and somatic embryogenesis have been studied as ways to multiply superior material faster, and the species is unusually responsive to tissue culture for a woody shrub. Seed remains the cheap method for a mixed planting, but only a cuttings programme gives a field that is predictably female.
Science & Biotechnology
Pressing the seed for wax leaves a protein-rich meal, and the meal is not straightforwardly usable as feed. It contains simmondsin, a cyanogenic glucoside that makes the meal unpalatable and interferes with appetite and growth in animals. Researchers have worked on strains with lower simmondsin and on ways of removing or detoxifying it, and the compound itself has been studied as an appetite-suppressing agent. It remains the main obstacle to using the meal as a protein source, and it is a good example of how a valuable crop can still have a difficult by-product.
Uses & Benefits
Nearly all vegetable oils are triglycerides, three fatty acids attached to a glycerol backbone. Jojoba seed stores its energy differently, as straight-chain esters joining a long-chain fatty acid directly to a long-chain fatty alcohol, with chain lengths in the region of twenty and twenty-two carbons and one double bond on each side of the join. The result is a liquid wax that behaves like an oil but is chemically an ester of a different family entirely, and it is remarkably stable against oxidation and heat. Because it resembles the waxes in animal tissue, it spreads on skin without feeling greasy, which is why the cosmetic trade is the largest consumer.
Jojoba wax is close in its properties to spermaceti, the oil taken from the sperm whale. When the United States banned the use of whale products at the start of the 1970s, the search for a plant substitute turned the desert shrub into an agricultural prospect almost overnight. The first significant plantings were made in the Negev and other arid regions, and the crop was later taken up in Argentina, Australia, Israel, Peru and India, usually on land too dry or too salty for anything else. Jojoba remains a small but genuinely global crop, and its wax is still sold as a high-end lubricant and cosmetic base as well as a replacement for animal waxes.
Growing from Seed
Jojoba seed is large and stores badly, so sow it fresh rather than keeping it in a drawer. Push each seed about its own depth into a coarse, sharply drained mix, keep it warm and water sparingly, and use a deep container, because the seedling sends a strong root straight down and resents being coiled. Plant out while the plant is still small, into a hole deep enough for the root to run without bending. Juvenile plants are frost-sensitive and benefit from a sheltered position or a little protection for their first winters; once past that stage they are tough, long-lived and mostly self-sufficient.
Its tolerances are unusual. It grows on salty, strongly alkaline soils and accepts irrigation water that would damage most crops, making it valuable on marginal land. It does not tolerate poor drainage, and it dislikes humid heat. The main drawback is time: seedling plants need several seasons before they carry a worthwhile crop, while cuttings still require a long establishment period.
Our Take
This is a plant for a hot, dry, sunny site with sharp drainage and a gardener who does not mind waiting. The foliage alone earns its place in a dry border, and the shade it casts is light enough for other desert plants to grow beneath it. For a similar planting scheme, Cistanche deserticola belongs to the same dry world, and Elaeagnus angustifolia tolerates the same alkaline ground while fixing its own nitrogen. Sea buckthorn is the other hardy oilseed shrub I would put on a windy, dry bank beside it.
Related Reading
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