Grow basil successfully. Basil is an annual warm-season herb, very susceptible to cold and frost. Sow seed in spring at a depth of about 1/2 inch in full sun. Keep the soil evenly moist. When the basil reaches about 6 inches, pinch out the top to encourage bushy growth. Pick continuously before any flower buds open. Pick leaves in the morning after dew has dried, and don't over wash leaves, as you will lose the aromatic oils.