How to Grow Black Seeded Simpson
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Black Seeded Simpson
Lactuca sativa var. crispa
vegetableBlack Seeded Simpson is a loose-leaf lettuce variety prized for its tender, crinkled green leaves and mild flavor. It's a cold-hardy, heat-tolerant cultivar that doesn't form a tight head, making it ideal for cut-and-come-again harvesting. This classic heirloom variety has been popular since the 1850s and is excellent for both home gardeners and market growers.
When should you plant Black Seeded Simpson in your zone?
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Example Black Seeded Simpson timeline · Pittsburgh, PA (Zone 6b)
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Plant Black Seeded Simpson
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Black Seeded Simpson
Around Jun 1≈ 45 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Black Seeded Simpson dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; grows year-round in milder climates with proper spacing
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Germination
7-10 daysSeeds sprout and first true leaves emerge. Seedlings are delicate with tiny leaves.
Keep soil moist but not soggy. Provide bright light. Maintain soil temperature 60-70°F for optimal germination (7-10 days). Avoid overwatering which causes damping-off.
Seedling
2-3 weeksPlant develops 2-4 true leaves and establishes a small root system. Leaves are tender and bright green.
Thin to proper spacing once seedlings have 2-3 true leaves. Keep soil evenly moist. Provide 12-16 hours of light daily if growing indoors. Avoid temperature extremes.
Vegetative Growth
3-4 weeksPlant produces multiple layers of crinkled leaves in a loose rosette formation. Leaves expand rapidly and become darker green.
Maintain consistent moisture and steady feeding. Begin light harvesting of outer leaves once plant is 6+ inches tall. Provide afternoon shade in temperatures above 75°F to prevent bolting.
Mature Harvesting
2-4 weeks or more with proper managementPlant reaches full size with abundant, tender crinkled leaves ready for harvest. Cut-and-come-again harvesting extends productivity.
Harvest outer leaves regularly to encourage continued growth and prevent bolting. Continue watering consistently. Apply light fertilizer every 2-3 weeks for sustained production.
Bolting
Occurs as temperatures exceed 75°F consistentlyPlant sends up a central flower stalk with smaller leaves and bitter flavor as it prepares to seed.
Once bolting begins, lettuce quality declines. Harvest immediately if not already done. Provide shade and consistent moisture to delay bolting in warm weather. Plant bolts more readily in heat and long daylight.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with strong water stream; use insecticidal soap; introduce ladybugs; neem oil as last resort
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and
Hand-pick early morning/evening; set beer traps; create barriers with diatomaceous earth; remove hiding spots
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Crop rotation; avoid planting in same location within 3 years; encourage beneficial insects; resistant varieties when available
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Yellow sticky traps; neem oil; reflective mulches; spray insecticidal soap weekly
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Hand-pick caterpillars; Bacillus thuringiensis (Bt); row covers; parasitic wasps
Uses
Fresh Salads & Salad Mixes
CulinaryBlack Seeded Simpson is excellent for fresh green salads due to its tender, delicate leaves and mild flavor. Its crinkled texture holds dressings well and adds visual appeal to mixed green dishes. [source]
Microgreens & Baby Leaf
CulinaryThe variety is well-suited for early harvesting as microgreens or tender baby leaves, offering quick, nutritious greens for sandwiches, wraps, and garnishes within 3-4 weeks. [source]
Continuous Harvest Production
HouseholdAs a loose-leaf variety, Black Seeded Simpson allows for cut-and-come-again harvesting that extends the productive season, making it economical for home gardeners and small farms. [source]
Nutritional Value & Antioxidants
MedicinalLike all lettuces, Black Seeded Simpson provides vitamins A, C, K, folate, and beneficial antioxidants. The crisp green leaves are low in calories and support healthy digestion. [source]
Heat-Tolerant Warm-Season Lettuce
CulinaryBlack Seeded Simpson is more heat-resistant than many lettuce varieties, making it valuable for extending the spring and summer growing season beyond typical lettuce limits. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Begin harvesting outer leaves once plant is 6+ inches tall (usually 4-5 weeks). Pinch or cut leaves from the outside working inward, leaving the center to continue growing. For baby leaf harvest, cut entire plant 1-2 inches above soil at 30-40 days and it may regrow. Morning harvest yields crispest leaves. Harvest before temperatures consistently exceed 75°F to avoid bitterness. Wash immediately and refrigerate to maintain crispness.
Fun Facts
- 🌱 Black Seeded Simpson is an heirloom variety first introduced in the 1850s and remains one of the most widely grown loose-leaf lettuces in home gardens today.
- 🌱 Unlike head-forming lettuces, Black Seeded Simpson was specifically bred for the cut-and-come-again harvesting method, allowing a single planting to produce leaves for weeks or even months.
- 🌱 The variety gets its name from the black color of its seeds; 'Simpson' refers to Alexander Simpson, an early American seedsman who popularized this cultivar in the 19th century.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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