What to Do With Black-Seeded Simpson Lettuce When it Flowers

Flowering

• Flowering signals that the lettuce is entering its reproductive stage, the fourth and final stage of its growth. The center stalk grows rapidly into a flower stalk, and the flower stalk blooms and then seeds. At this point of the growth cycle, nutrients cease going into the formation of tasty leaves and are instead directed into seed production. The flowering process causes the previously succulent lettuce leaves to become tough and bitter.

Premature Flowering

• Lettuce requires short days to grow, which is one thing that makes it suitable for spring and fall crops. Once the adequate number of daylight hours is reached, the lettuce begins to bolt, or flower. Lettuce that receives too much light will bolt prematurely; this can happen with the excessive use of grow lights. Extended periods of heat and drought also cause early bolting and ruination of lettuce crops.

Preventing Premature Bolt

• The best way to prevent bolt is to sow the lettuce in the spring when soil temperatures reach 40 degrees Fahrenheit and daytime temperatures are 45 to 75 degrees Fahrenheit. Keeping the soil adequately moist is also important; since lettuce is almost 95-percent water, it needs an inch of rain or watering per week to keep it going. Covering the lettuce towards the end of production with a sheet propped up with stakes to shade it will also stall bolt; planting taller plants like tomatoes or peppers next to it to shade it on warmer days also can help.

What to Do

• You have two options once your lettuce flowers. The first is to harvest the lettuce and either eat it or discard it if you do not like the taste. If washed and stored in the refrigerator for a couple of days, some bitterness in taste may subside so that it is edible. You can also allow the lettuce to fully seed and then collect the seeds for future planting. This practice is difficult, as collected seeds that are more than a year old usually will not germinate. It is best to start with fresh, purchased seeds in the spring, then collect seeds from your crop and use them for a fall planting.