How to Grow Black Seeded Simpson Lettuce

Black Seeded Simpson Lettuce

Lactuca sativa var. crispa

vegetable

Black Seeded Simpson is a classic loose-leaf lettuce variety prized for its tender, frilly green leaves and excellent flavor. It's a heat-tolerant heirloom variety that produces abundant foliage without forming a tight head. This fast-growing lettuce is ideal for succession planting and continuous harvests throughout the season.

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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 direct sunlight daily; afternoon shade in hot climates (above 75°F) prevents bolting
💧
Water: Consistently moist soil; water 1-1.5 inches per week; keep soil evenly moist but not waterlogged; water at soil level to prevent disease
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Spacing: 6-8 inches apart; thin seedlings to this spacing when 2-3 inches tall inches
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Days to maturity: 45-60 days for full plant; 30-40 days for baby leaf harvesting
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Planting depth: 0.25 inches; surface sow and keep moist until germination (5-7 days)

Soil

Type: Well-draining loamy soil rich in organic matter
pH: 6.0-6.8
Amendments:
compost aged manure peat moss perlite for drainage

Growing Zones

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Thrives in zones 4-9; can grow year-round in mild climates

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

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Growth Stages

1

Germination & Seedling

7-14 days

Tiny cotyledons emerge and develop 2-3 true leaves; delicate seedlings with minimal root system

Keep soil consistently moist but not waterlogged; provide bright light; maintain 60-70°F temperatures; thin to proper spacing when 2-3 inches tall

2

Vegetative Growth

14-21 days

Plant develops 4-8 leaves; foliage becomes increasingly frilly and vibrant green; rosette form begins to establish

Maintain consistent moisture; apply balanced fertilizer every 2-3 weeks if needed; monitor for slugs and aphids; provide afternoon shade in hot weather

3

Leaf Development & Expansion

15-25 days

Frilly, deeply lobed leaves multiply and expand rapidly; plant forms a loose, open rosette; stems remain tender and succulent

Continue regular watering; watch for bolting in heat (plant will form flower stalk); harvest outer leaves to encourage continued production; increase watering frequency in heat

4

Harvest-Ready & Maturity

Ongoing (2-4 weeks or more)

Plant reaches full size with abundant crispy, tender leaves; rosette is full and productive; maximum flavor and texture achieved

Begin harvesting outer leaves immediately; can continue harvesting for 2-4 weeks if managed properly; pinch off any flower buds that form; provide afternoon shade to extend harvest window

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

cabbage broccoli cauliflower fennel

Common Pests

  • Spray with water to dislodge; use insecticidal soap; introduce ladybugs; neem oil as last resort

  • and

    Hand-pick at dusk; use copper tape barriers; shallow dishes of beer; diatomaceous earth around plants

  • Remove infected plants; control aphid populations; choose resistant varieties; sanitize tools

  • Remove affected leaves; use row covers on young plants; spinosad spray if severe

  • Ensure good air circulation; avoid overhead watering; remove infected leaves; sulfur dust fungicide

Uses

🍳

Fresh salads and greens

Culinary

Black Seeded Simpson's tender, frilly leaves are perfect for fresh salads, lettuce wraps, and green smoothies. The delicate texture and mild, slightly sweet flavor make it ideal for both gourmet and everyday eating. [source]

🍳

Baby leaf microgreens

Culinary

Young, tender Black Seeded Simpson leaves can be harvested at 30-40 days as baby greens, offering concentrated flavor and tenderness for upscale culinary applications and restaurant presentations. [source]

💊

Nutritional greens

Medicinal

Lettuce is rich in vitamin K, folate, and antioxidants. It contains compounds that support bone health and may have mild sedative properties, making it valued in traditional herbal medicine. [source]

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Continuous garden harvesting

Household

Black Seeded Simpson's leaf-by-leaf harvest capability allows home gardeners to enjoy fresh lettuce continuously throughout the season without replanting, making it economical and sustainable. [source]

🦋

Pollinator and beneficial insect support

Wildlife

When allowed to bolt, Black Seeded Simpson produces small yellow flowers that attract bees and provide food for beneficial insects. The seeds also feed birds and finches. [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 plant is 4-6 inches tall (30-40 days); use scissors or pinch leaves off at base; harvest in early morning for crispest texture; can harvest individual leaves continuously or cut entire plant 1-2 inches above soil for regrowth; best flavor when harvested cool and tender; avoid harvesting during heat of day

Fun Facts

  • 🌱 Black Seeded Simpson is an heirloom variety that has been grown continuously since the 1850s, making it one of the longest-established lettuce varieties still in common cultivation.
  • 🌱 The 'black seeded' designation refers to the dark color of the seeds, which distinguishes it from white-seeded lettuce varieties; the seed color does not affect the leaf color or flavor.
  • 🌱 This lettuce variety is particularly heat-tolerant compared to other loose-leaf lettuces, making it ideal for spring and early summer gardens where other lettuces might bolt quickly.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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