Lettuce

Basic Information

Seed Number

154

Seed Name

Lettuce

Variety

Grand Rapids

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

7–10 days

Harvest/Maturity

45 days

Succession Planting

14 days

Growing Conditions

Ideal Soil Temperature

40-70°F

Planting Depth

1/8-1/4 in

Plant Spacing

6-8 in

Row Spacing

12-18 in

Thin-To Spacing

6-8 in

Sun Requirements

Full sun to partial shade

Water Needs

About 1 in/week; maintain consistent moisture because lettuce is shallow rooted

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; McKenzie Seeds; 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 for transplanting. Grow as baby leaf or space for full plants.
Original Start Planting Date: Mar 20 – Mar 25
Original Last Suggested Planting Date: ~Aug 25 for fall crop
Outdoor / Direct Sow / Transplant Window: Spring sow/transplant ~Mar 25 – May 15. Fall sow ~Jul 25 – Aug 25.
Days to Harvest / Bloom: ~45 days full size; baby leaf ~21–30 days
Container Friendly: Yes; excellent; ~6+ in deep container
Pollinator Friendly: Low normally; bolted flowers can feed small pollinators
Medicinal / Herbal Use: Culinary leafy green
Succession / Reusable Notes: Sow every 1–2 weeks during cool spring/fall windows for continuous harvest.
Zone 6B Notes: Best as spring and late-summer/fall crop in Zone 6B. Row cover can extend season. Avoid relying on midsummer sowing during hot weather.
Companion Plants: Carrots, peas, radishes, onions, taller crops providing light summer shade
Avoid Planting Near / Watch Outs: Heat causes bolting/bitter leaves. Slugs can be a problem. Lettuce seed germinates poorly in very hot soil.
Sources: Urban Farmer: https://www.ufseeds.com/product/grand-rapids-tbr-lettuce-seeds---1-pound/LEGR-1-pound.html | McKenzie Seeds: https://mckenzieseeds.com/products/lettuce-grand-rapids | UMN Extension: https://extension.umn.edu/vegetables/growing-lettuce-endive-and-radicchio

[[RESEARCH ENRICHMENT START]]
Zone 6B: Grand Rapids is a cool-season loose-leaf lettuce. Grow in spring and again from late summer into fall. It is slower to bolt than many leaf lettuces but still performs poorly during sustained summer heat.
Germination: Lettuce germinates best in cool soil. Germination can be inhibited when soil temperatures rise above approximately 75-80°F.
Harvest: Begin harvesting outer leaves as needed or cut the entire loose-leaf plant at approximately 45 days.
Seed Saving: Allow selected plants to bolt, flower and develop dry seed heads. Lettuce is primarily self-pollinating.
Special Care: Grand Rapids produces large, frilly, bright-green leaves and is valued for rapid growth and relatively slow bolting.
Research Source: Ferry-Morse — https://ferrymorse.com/products/lettuce-grand-rapids — Lactuca sativa identity, loose-leaf type, approximately 45-day maturity, frilly green leaves and slow-bolting characteristic
[[RESEARCH ENRICHMENT END]]