Crop lessons · Leafy greens
Growing Lettuce in Florida
Lactuca sativa · Asteraceae (aster family)
Winter is lettuce season in Florida. All four types (leaf, romaine, butterhead and crisphead) can be grown, but leaf types suit the mild climate best and crisphead only does well in the coolest months. Heat is the enemy: it makes lettuce bolt and turn bitter.1, 2
Planting2, 1
| How to start | seed or transplant (easily transplanted) |
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| Seed depth (inches) | ¼ (sow very shallowly: seeds need light to germinate) |
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| Spacing in the row (inches) | 8 to 12 (SP 103); Gardening Solutions says 6 to 8 for transplants, at least 10 for crisphead |
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| Between rows (inches) | 18 |
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| Days to harvest | 60 to 80 (SP 103); Gardening Solutions says ready within 4 to 6 weeks of planting |
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SP 103 planting dates: north Feb to Mar, central Sept to Feb, south Sept to Feb. Prefers 50°F to 75°F. Above 85°F give afternoon shade or shade cloth; below 40°F cover with a frost blanket. Damaged by freezing temperatures. Can be grown in the ground, raised beds, containers or a floating hydroponic setup.
Varieties UF/IFAS lists for Florida2, 1
- Great Lakes (crisphead)
- Ermosa (butterhead)
- Bibb (butterhead)
- Tom Thumb (butterhead)
- Buttercrunch (butterhead)
- Black-seeded Simpson (leaf)
- Salad Bowl (leaf)
- Red Sails (leaf)
- New Red Fire (leaf)
- Oak Leaf (leaf)
- Royal Oak (leaf)
- Parris Island Cos (romaine)
- Valmaine (romaine)
- Dark Green Cos (romaine)
- Outredgeous (romaine)
Growing1, 2
| Sun | At least 10 hours of sunlight a day. |
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| Soil pH | 6.0 to 6.5 |
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| Water | Keep soil evenly moist but not soggy; soggy soil invites disease. |
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| Fertilizer | A balanced slow-release fertilizer at planting. SP 103 notes that leafy crops such as lettuce, kale and collards benefit from side-dressings of a nitrogen fertilizer during the season (general advice for leafy vegetables). |
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Well-drained soil with compost. Mulch and weed-control fabric keep weeds down. Lettuce can be tucked between taller or longer-season crops.
Pests and diseases in Florida1, 2
- Aphids: Named as a common lettuce pest.
- Slugs and snails: SP 103 recommends iron phosphate baits; metaldehyde baits are extremely toxic to pets and wildlife.
Harvest1
Cut the larger outer leaves of leaf, butterhead and romaine types and let the center grow on, or cut the whole head about two-thirds of the way down, leaving the crown to regrow for further cuttings. Crisphead is cut once, as a whole head. Crisphead keeps 2 to 3 weeks in the refrigerator; other types about a week, bagged in the crisper.
In an aquaponics system3, 4
well suited
Both aquaponic sources single lettuce out. FAO says it grows particularly well in aquaponics and has low nutrient demand: pH 6.0 to 7.0, 24 to 32 days to harvest, and bolting when nights stay above 18 °C or water tops 26 °C. Keeping nitrate high gives crisp, sweet heads, and extra calcium helps prevent tip burn in summer. SRAC 454 reports lettuce takes 3 to 4 weeks in a raft system (Bibb 3 weeks, red and green leaf 4 weeks), and warns that sodium above 50 mg/L cuts calcium uptake and causes tip burn, most often in warm months.
What this lesson doesn't cover yet
- Days to harvest differ widely: SP 103 says 60 to 80 days, Gardening Solutions 4 to 6 weeks (likely counting from transplant or for baby leaves, though the page does not say).
- SP 103 lists 'Salad Bowl' twice in its loose-leaf list; it is listed once here.
Your county extension office and its Master Gardener volunteers can fill these in for your garden.