How to Grow Purple-seeded Simpson Lettuce

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Purple-seeded Simpson Lettuce

Lactuca sativa var. crispa

vegetable

Purple-seeded Simpson is a loose-leaf lettuce variety known for its frilly, deeply lobed green leaves with purple-tinged stems and seed pods. This cold-hardy, bolt-resistant variety is ideal for both spring and fall gardens, offering tender leaves perfect for salads and continuous harvesting.

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Example Purple-seeded Simpson Lettuce timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Purple-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 Purple-seeded Simpson Lettuce

    Around Jun 1

    ≈ 45 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Purple-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 helps in hot climates)
💧
Water: Consistent moisture; keep soil evenly moist but not waterlogged. Water deeply 1-2 times weekly, more frequently in hot weather. Mulch to retain moisture.
📏
Spacing: 6 inches
📅
Days to maturity: 45-60 days
🌱
Planting depth: 0.25 inches (seeds planted shallow, just barely covered)

Soil

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

Growing Zones

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Thrives in zones 2-9, best for cool-season growing in spring and fall

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

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Growth Stages

1

Germination & Seedling

2-3 weeks

Seeds sprout in 7-10 days. Tiny seedlings emerge with first true leaves appearing within 2 weeks.

Keep soil consistently moist but not soggy. Provide bright light; thin seedlings to proper spacing if direct seeded. Maintain cool temperatures (60-65°F ideal).

2

Vegetative Growth

3-4 weeks

Loose rosette of frilly, deeply lobed leaves develops. Leaves grow increasingly ruffled and develop purple tinges on stems and leaf margins.

Water regularly; mulch around plants. Apply balanced fertilizer every 2-3 weeks. Monitor for pests. Thin crowded plants if needed.

3

Leaf Development & Harvesting

2-3 weeks (ongoing if harvesting continuously)

Mature outer leaves become harvestable (4-6 inches long). Plant continues producing new leaves from center if managed as cut-and-come-again.

Begin harvesting outer leaves when 4-6 inches long. Keep soil evenly moist. Watch for heat stress; provide afternoon shade if temperatures exceed 75°F.

4

Bolting (End of Season)

1-2 weeks

Center of plant elongates, flower stalk emerges, leaves become bitter and more rigid. Purple-tinged seed pods develop.

Harvest remaining leaves immediately as quality declines. Pull plant once bolting begins and replant with fall crop. Compost bolted plants.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Cabbage Broccoli Cauliflower Fennel

Common Pests

  • Spray with insecticidal soap or neem oil; encourage beneficial insects like ladybugs; use row covers on young plants

  • and

    Hand-pick; use copper tape barriers; set beer traps; apply diatomaceous earth; encourage ground beetles

  • Use resistant varieties; practice crop rotation; apply neem oil; solarize soil before planting

  • Spray with insecticidal soap; use yellow sticky traps; introduce parasitic wasps

  • Improve air circulation; avoid overhead watering; apply sulfur or copper fungicide; remove infected leaves

Uses

🍳

Fresh salads and greens

Culinary

Purple-seeded Simpson's tender, frilly leaves are perfect for salads, sandwiches, and fresh cooking applications. The delicate texture and mild flavor make it ideal for gourmet salad mixes and garnishes. [source]

🍳

Continuous harvest greens

Culinary

The cut-and-come-again harvesting method allows gardeners to enjoy fresh lettuce throughout the season from a single planting, providing weeks of tender leaves. [source]

🌿

Vitamins and minerals

Nutritional

Rich in vitamin K, vitamin A, folate, and antioxidants. Provides dietary fiber and contains beneficial compounds that support bone health and eye function. [source]

🏠

Cool-season microgreens

Household

Purple-seeded Simpson seeds can be sprouted as microgreens indoors in 10-14 days, providing nutrient-dense baby greens year-round. [source]

🦋

Pollinator and beneficial insect support

Wildlife

When allowed to bolt and flower, Purple-seeded Simpson provides nectar and pollen for pollinators and beneficial insects that help control garden pests. [source]

Harvest Tips

Harvest outer leaves when 4-6 inches long, beginning 45-60 days from planting. Use cut-and-come-again method: snip leaves 1-2 inches above soil line with clean scissors, leaving center intact to regrow. Early morning harvest yields crispest leaves. For whole-head harvest, cut just above soil line when plant reaches desired size. Best harvested before bolting; quality declines in heat.

Fun Facts

  • 🌱 Purple-seeded Simpson gets its name from its distinctive purple-tinged seeds and the Simpson family of lettuce varieties, which are prized for their frilly, attractive foliage.
  • 🌱 This variety is notably bolt-resistant compared to many other lettuces, making it one of the most reliable choices for gardeners who struggle with early bolting in spring gardens.
  • 🌱 The purple pigmentation in the stems and seed pods comes from anthocyanins, the same beneficial compounds found in blueberries and red wine.

Gardening Terms

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

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