How to Grow Black Seeded Simpson Lettuce

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Black Seeded Simpson Lettuce

Lactuca sativa var. crispa

vegetable

Black Seeded Simpson is a loose-leaf lettuce variety prized for its tender, frilly, deeply lobed leaves with a mild, sweet flavor. It forms open heads rather than tight heads and is extremely prolific, allowing for successive harvests of outer leaves. This cold-tolerant variety is ideal for spring and fall growing and performs well in containers or garden beds.

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Example Black Seeded Simpson Lettuce timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Black Seeded Simpson Lettuce

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Black Seeded Simpson Lettuce

    Around Jun 1

    ≈ 45 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Black Seeded Simpson Lettuce dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to partial shade; 4-6 hours of sunlight daily (more shade in hot climates)
💧
Water: Consistently moist but not waterlogged; water 1-1.5 inches per week. Drought stress causes bolting and bitterness. Keep soil evenly moist for tender leaves.
📏
Spacing: 6-8 inches apart inches
📅
Days to maturity: 45-60 days to full head; can harvest outer leaves in 30-40 days
🌱
Planting depth: 0.25-0.5 inches; seeds should be barely covered

Soil

Type: Well-draining, fertile loamy soil rich in organic matter
pH: 6.0-7.0
Amendments:
Compost aged manure peat moss balanced organic fertilizer

Growing Zones

Find your zone →

Thrives in zones 2-9; prefers cooler seasons (spring and fall)

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b

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Growth Stages

1

Germination & Seedling

2-3 weeks

Seeds sprout within 7-10 days at 60-70°F. Tiny seedlings emerge with cotyledons (seed leaves), followed by first true leaves.

Keep soil consistently moist but not soggy. Provide bright light immediately after germination to prevent leggy seedlings. Thin seedlings to proper spacing when 2-3 inches tall.

2

Vegetative Growth

3-4 weeks

Plant develops increasingly large, frilly leaves in an open rosette pattern. Leaves become more deeply lobed and tender. No center head formation occurs.

Water consistently and mulch to retain moisture. Apply balanced fertilizer every 2 weeks if soil is not rich in organic matter. Keep soil cool with shade cloth if temperatures exceed 75°F.

3

Leaf Development & Harvest Window

4-6 weeks (can extend with succession planting)

Outer leaves reach full size and develop maximum tenderness and flavor. Plant continues to produce new inner leaves throughout the season.

Begin harvesting outer leaves once they reach 4-6 inches long. This encourages continued production and extends harvest window. Continue consistent watering and watch for bolting as temperatures rise.

4

Peak Production

2-4 weeks

Plant is at maximum leaf production with tender, fully-sized leaves continuously emerging from the center.

Harvest regularly (2-3 times per week) to encourage more leaf production and prevent bolting. Maintain even soil moisture and cooler temperatures through mulching or shade.

5

Bolting & Decline

7-10 days

Plant begins to elongate and send up a flower stalk, especially in heat. Leaves become tougher, smaller, and more bitter.

Once bolting begins, harvest remaining leaves quickly or remove the plant. In spring, bolt earlier; in fall, extend season with shade cloth. Use bolted plants for flower arrangements or compost.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Cabbage broccoli cauliflower parsnips

Common Pests

  • Spray with strong water jet to dislodge; use insecticidal soap or neem oil; encourage beneficial insects like ladybugs

  • and

    Hand-pick in early morning; use beer traps or copper barriers; apply diatomaceous earth around plants

  • Ensure good air circulation; avoid overhead watering; remove affected leaves; plant resistant varieties; thin overcrowded plants

  • Use paper collars around seedlings; apply Bacillus thuringiensis (Bt); remove plant debris where they overwinter

  • Use row covers on seedlings; apply neem oil or spinosad; remove infected leaves

Uses

🍳

Fresh Salads & Greens

Culinary

Black Seeded Simpson's tender, frilly leaves are perfect for fresh salads, wraps, and delicate green mixes. The sweet, mild flavor pairs well with vinaigrettes and fresh vegetables. [source]

🍳

Sautéed & Cooked Greens

Culinary

Outer, more mature leaves can be gently wilted in butter or olive oil as a side dish, though they're best enjoyed raw. The delicate structure means it requires minimal cooking time. [source]

🏠

Continuous Harvesting for Self-Sufficiency

Household

The loose-leaf structure and prolific production make Black Seeded Simpson ideal for gardeners seeking a prolonged harvest from a small space. Succession planting every 2-3 weeks ensures continuous fresh greens throughout the growing season. [source]

💊

Nutritional & Antioxidant Source

Medicinal

Lettuce is rich in vitamins A, K, and folate, as well as antioxidants and fiber. Regular consumption supports bone health, vision, and overall wellness. [source]

🦋

Pollinator & Beneficial Insect Support

Wildlife

When bolting, Black Seeded Simpson produces delicate yellow flowers that attract beneficial pollinators and insects. Allowing a few plants to flower supports garden ecosystem health. [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 when they reach 4-6 inches long, typically 30-40 days after planting. Use the 'cut and come again' method: pinch or cut outer leaves at the base, allowing the center to continue producing. Harvest in the cool morning for maximum crispness. Continue harvesting until the plant bolts (sends up a flower stalk), which typically occurs when temperatures exceed 75°F for extended periods. For best flavor and texture, harvest before 10 AM when leaves are fully hydrated. Whole plants can be cut 1-2 inches above soil level for a second, smaller flush of leaves.

Fun Facts

  • 🌱 Black Seeded Simpson has been grown since the 1850s and remains one of the most reliable and beginner-friendly loose-leaf lettuce varieties worldwide.
  • 🌱 Unlike heading lettuces that require tying or mature head formation, Black Seeded Simpson can be harvested as a 'cut and come again' crop, producing leaves for 8-10 weeks from a single plant.
  • 🌱 The variety earned its name from its distinctively dark/black seeds, which were unusual for lettuce varieties of that era and made seed selection and breeding easier for early horticulturists.

Gardening Terms

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