Thai basil plants should only be watered at the base; watering the leaves can cause overhydration, which leads to dropping and yellowing leaves. Too little water damages the flowers and buds, so it is necessary to give them a balanced amount of water on a weekly basis.
A solution of fish emulsion and seaweed should be applied two or three times throughout the season while the plant is developing. The soil should contain plenty of nutrients. Harvest the leaves in the morning, and water the plant before harvesting to improve the flavor.Learn more about Outdoor Plants & Flowers