60 to 90 days. Thai basil has lush, deep green leaves, purplish flower buds and stems, and carries anise overtones to its sweet basil scent. It is added by the big handfuls in whole leaves, to green and red curries and spicy stir-fried dishes; sprigs of it regularly appear with other herbs on vegetable platters to be nibbled on with spicy salads and chili dips.