How to Fertilize Garden Lettuce

When Should I Start Feeding My Lettuce?

How Often Should I Fertilize My Lettuce?

Feed every two weeks from the time seedlings develop their first set of true leaves. Lettuce is a fast grower, especially in cool weather, and it will reward consistent feeding with bigger, more tender leaves.

For cut-and-come-again varieties, give a light feeding after each major harvest to fuel the next flush of growth. For head lettuce, maintain the biweekly schedule until the head starts to firm up, then stop.

Signs of over-fertilizing include dark green, brittle leaves with brown edges. If you see this, flush the soil with plain water and skip your next feeding. Lettuce that bolts (sends up a flower stalk) is usually reacting to heat, not fertilizer.

What Is the Best Fertilizer for Lettuce?

Lettuce is a leafy green, so nitrogen is the most important nutrient. Look for a liquid fertilizer with a higher first number in the NPK ratio, like 10-5-5 or 24-8-16. The nitrogen drives the lush leaf growth you are harvesting.

Liquid fertilizer is the best option because lettuce has a short life cycle and needs nutrients it can absorb quickly. Dilute to half the label strength to avoid burning the shallow roots. Apply it directly to the soil, not the leaves.

For garden beds, a side-dressing of compost or a balanced granular fertilizer worked into the soil before planting gives lettuce a strong start. Then follow up with liquid feedings every two weeks once the plants are established.

How Do I Fertilize My Lettuce?