Lettuce

Basic Information

Seed Number

156

Seed Name

Lettuce

Variety

Black Seeded Simpson

Category

Vegetable

Plant Family

Asteraceae

Plant Type

Loose-leaf lettuce (Lactuca sativa)

Planting Method

Direct Sow or Transplant

Seed Status

In Seed Bank

Created

2026-08-14 00:50:34

Updated

2026-08-19 15:35:29

Planting Information

Start Planting Date

Mar 10

Last Recommended Planting Date

Sep 1

Plantable Months

March, April, May, July, August, September

Indoor Start

Mar 10 – Apr 1

Direct Sow

Apr 1 – Aug 31

Transplant

Apr 15 – Sep 1

Indoor Start Weeks Before Frost

8 weeks

Transplant Weeks After Frost

Not recorded

Germination Days

4–10 days

Harvest/Maturity

32–46 days 32 days baby leaf; 46 days full size

Succession Planting

14 days

Growing Conditions

Ideal Soil Temperature

60-68°F

Planting Depth

1/8 in

Plant Spacing

8-10 in

Row Spacing

12-18 in

Thin-To Spacing

8-10 in

Sun Requirements

Full sun to partial shade

Water Needs

Maintain consistent moisture; lettuce is shallow rooted and should not be allowed to dry out

Soil Preference

Fertile, moisture-retentive but well-drained soil rich in organic matter

Minimum Container Size

6-8 in deep

Plant Height

Not recorded

Perennial/Biennial Status

Annual

Container Friendly

Yes

Trellis/Support Needed

No

Frost Tolerant

Yes

Heat Tolerant

No

Drought Tolerant

No

Pollinator Friendly

No

Medicinal

No

Garden Uses

Companion Planting

Storage

Seed Source/Brand

Urban Farmer; Botanical Interests; UMN Extension

Packet Year

Not recorded

Quantity Notes

Not recorded

Purchase Date

Not recorded

Expiration Year

Not recorded

Storage Box

Not recorded

Container

Not recorded

Envelope

Not recorded

Row

Not recorded

Slot

Not recorded

Storage Notes

Not recorded

Notes

Original Planting Method: Direct sow in cool soil or start indoors. Excellent for baby leaf, cut-and-come-again harvest, or full loose-leaf plants.
Original Start Planting Date: Mar 20 – Mar 25
Original Last Suggested Planting Date: ~Aug 25
Outdoor / Direct Sow / Transplant Window: Spring sow/transplant ~Mar 25 – May 20. Fall sow ~Jul 25 – Aug 25.
Days to Harvest / Bloom: ~28 days baby leaf; ~45 days full size
Container Friendly: Yes; excellent; ~6+ in deep container
Pollinator Friendly: Low normally; bolted flowers can support small pollinators
Medicinal / Herbal Use: Culinary leafy green
Succession / Reusable Notes: Sow every 2–3 weeks in cool weather for continuous harvest. Can be harvested repeatedly by taking outer leaves.
Zone 6B Notes: Very useful for Zone 6B because it matures quickly and tolerates variable spring weather. Plant again in late summer for fall harvest.
Companion Plants: Carrots, peas, radishes, onions, taller plants offering light afternoon shade
Avoid Planting Near / Watch Outs: More heat tolerant than some lettuces, but high heat still causes bolting/bitterness. Keep soil cool/evenly moist.
Sources: Urban Farmer: https://www.ufseeds.com/product/black-seeded-simpson-lettuce-seeds/LEBSS.html | Botanical Interests: https://www.botanicalinterests.com/products/black-seeded-simpson-lettuce-seeds | UMN Extension: https://extension.umn.edu/vegetables/growing-lettuce-endive-and-radicchio

[[RESEARCH ENRICHMENT START]]
Zone 6B: Black Seeded Simpson is a hardy cool-season loose-leaf lettuce. Grow primarily in spring and again from late summer into fall; prolonged summer heat can cause bolting and poor germination.
Germination: Seed germinates best below 70°F and can germinate in soil as cool as 40°F. High soil temperatures above about 75°F can inhibit germination.
Harvest: Harvest individual outer leaves as needed, cut baby leaves around 32 days, or harvest full-size plants around 46 days.
Seed Saving: Black Seeded Simpson is open-pollinated. Allow selected plants to bolt, flower and form mature dry seed heads before collecting seed.
Special Care: Succession sow every 2-3 weeks during cool weather for a steady supply.
Research Source: Johnny's Selected Seeds — https://www.johnnyseeds.com/vegetables/lettuce/leaf-lettuce/black-seeded-simpson-lettuce-seed-425N.html — Black Seeded Simpson identity, 32-day baby leaf and 46-day full-size maturity, annual lifecycle, open-pollinated status, soil temperature, spacing, sowing depth and succession planting
Research Source: Pinetree Garden Seeds — https://www.superseeds.com/products/black-seeded-simpson-lettuce-46-days — 4-10 day germination and 46-day maturity
[[RESEARCH ENRICHMENT END]]