Jatropha seeds are oily and can be stored for 6 months without loosing their oil content. If seeds are stored longer, the oil content will diminish. Research on viability of Jatropha seeds shows a clear decrease depending on the length of storage. Seeds older than 15 months show at least a 50% lower oil content.

J. curcas grows best on well-drained soils (preferably pH 6-9) with good aeration. The plant can also grow on marginal soils with low nutrient content, but the oil content will most probably be lower. Therefore, it is imperative to test the soil before a Jatropha plantation is started.

J. curcas grows well with more than 600 mm rainfall per year and it can with­stand long periods of drought. The plant sheds its leaves during a prolonged dry season. The plants also survive too much rain. I have seen a nursery in Hainan that was affected by a tornado. After the storm, the nursery was as flat as a pancake and I remember how sad the farmers were, thinking the crop would be lost. Two months later, however, all the plants were standing happily erect again.

Ideal temperatures should average 20-30°C (68-90°F). Jatropha can, however, withstand a very light frost for 1-2 days, which causes it to lose all its leaves and may produce a sharp decline in seed yield. In Florida, less and less oranges are growing due to prolonged frost. Thus, I think growing Jatropha in Florida would be a risky business.

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