How to Fertilize Lettuce
Feed for fast, tender leaf growth
Quick Reference
Why Lettuce Needs Nitrogen
Lettuce is all about the leaves. Unlike fruiting vegetables that need phosphorus and potassium for flowers and fruit, lettuce benefits most from nitrogen which promotes:
- Fast, vigorous leaf growth
- Deep green color
- Tender, succulent leaves
- Quick crop turnaround
Fertilizing Schedule
At Planting
Mix compost or a balanced fertilizer into the soil before planting. This provides a good foundation for young plants.
2-3 Weeks After Planting
Apply nitrogen-rich fertilizer (fish emulsion, blood meal, or synthetic high-N fertilizer) once seedlings are established with 3-4 true leaves.
Mid-Growth
For head lettuce, apply one more feeding at mid-growth. For cut-and-come-again lettuce, feed after each major harvest to support regrowth.
Best Fertilizers for Lettuce
Organic Options
- • Fish emulsion - Fast-acting nitrogen
- • Blood meal - High nitrogen, slow release
- • Compost tea - Gentle, balanced
- • Worm castings - Mild, won't burn
Synthetic Options
- • 10-5-5 - High nitrogen formula
- • 20-10-10 - Strong N boost (use diluted)
- • Water-soluble - Fast-acting
- • Slow-release - Steady feeding
Watch Out For
- • Over-fertilizing - Causes rapid, weak growth prone to bolting and disease
- • Fertilizer burn - Keep granules away from leaves; water after applying
- • Bitter leaves - Can result from too much nitrogen combined with heat stress
- • Late fertilizing - Stop feeding 1-2 weeks before harvest
Frequently Asked Questions
How often should I fertilize lettuce?
Fertilize lettuce every 2-3 weeks with a nitrogen-rich fertilizer. Since lettuce has a short growing cycle (30-60 days), it only needs 2-3 applications total.
What's the best fertilizer for lettuce?
Lettuce needs nitrogen for leafy growth. Use a high-nitrogen fertilizer (like 10-5-5) or organic options like fish emulsion, blood meal, or compost tea.
Can you over-fertilize lettuce?
Yes - too much fertilizer can burn leaves, cause excessive growth that's prone to bolting, and create bitter-tasting leaves. Follow package directions carefully.
Does lettuce need fertilizer in containers?
Container lettuce benefits from light, regular feeding every 2 weeks. Use diluted liquid fertilizer since nutrients wash out faster in pots.