Why Is My Basil Bitter?

Flowering

• As basil grows, it eventually produces flowers and seeds. These flowers may have some ornamental value, but from a culinary standpoint, they mark the end of the basil season. Once the plant begins producing flowers, the leaves become bitter and less appealing. Pinch the plants back every two to three weeks to form a compact bushy plant and prevent flowering.

Watering

• Lack of sufficient water may stress basil plants and cause them to produce flowers prematurely. Water basil plants in the garden at least weekly, or as needed, to keep the soil evenly moist. Water container-grown basil daily, if necessary, to keep the plant moist. Basil originated in the humid climate of India and needs warm, moist conditions.

Variety

• Flowering is the most likely cause of a bitter taste, but basil leaves vary considerably depending on the variety. Sweet basil is the most commonly grown basil, but if you accidentally planted another variety, such as cinnamon basil or spicy globe basil, the taste may come as an unexpected surprise.

Solutions

• Once a plant begins flowering, the only solution is to pull it up and discard it. To prevent flowering in the future, plant the basil in full sun and water it regularly. Make several plantings two to three weeks apart for a steady supply of basil throughout the summer. Plant frost-tender basil only after the last expected frost. Bring it indoors for the winter or treat it as an annual.