Watering: Water Basil frequently during dry periods.
Fertilizer: Upon planting, add organic nutrients to the soil such as compost, blood meal or cottonseed meal. Feed with liquid plant food every few weeks to encourage growth, but be sure to not use fertilizers that leave a harmful residue since you will be consuming the leaves.
Harvesting: Picking leaves regularly encourages more growth. Harvest the leaves by pinching them off of the stem, and always harvest from the top of the plant. Basil can be frozen to preserve its flavor, used fresh or dried.
Tips: The biggest threat to a basil plant is root rot from poor drainage, so ensure the planting site has adequate drainage. Also, watch out for pests such as aphids, slugs or Japanese beetles.