Do not buy vetiver seed(i) You should be planting sterile, non-invasive vetiver, and (ii) more often than not, the seed that is sold is not vetiver. Always check with the supplier which species and cultivar of C. zizanioides they sell, and its original source if possible. Other species are also sold, particularly C. nigritana (African native) and C. nemoralis (Southeast Asia, mainly Thailand); both produce seed.