key growing information

Pelleted Lettuce Growing Information

How to grow lettuce from pelleted seed: cool-season timing, watering pellets, shelf life, thermal dormancy, transplanting heads, direct sowing baby leaf, harvest and storage.

By Hensley’s Seed Co. September 3, 2026

Pelleted Lettuce - Key Growing Information

Lettuce trials being evaluated at a research farm; pelleted seed is available for many of our lettuce varieties.

SCIENTIFIC NAME:

Lactuca sativa

CULTURE:

Lettuce is a hardy, cool-season crop you can plant as soon as the soil can be worked. It grows best at 60–65°F (16–18°C) and sprouts best under 70°F (21°C), so for hot weather, choosing the right variety matters. Sow again every 2–3 weeks for a steady supply of heads or salad mix.

PELLETED SEED:

Pelleted seed needs a bit more care with watering: it does best when the soil stays evenly, moderately moist right through germination. The first watering splits or dissolves the coating, and if the soil then dries out before germination is complete, the seed may not get enough moisture to sprout well.

PELLET STORAGE:

Pelleting has many benefits, but it does shorten the seed's shelf life, so we suggest using pelleted seed within a year of purchase. Until planting, keep it somewhere cool, dark and dry, away from heat and humidity. If you'd rather keep it in the refrigerator, seal it in an airtight container to protect it from swings in humidity.

THERMAL DORMANCY:

High temperatures can push lettuce seed into , so it fails to sprout. Germination is best with soil at 60–68°F (15.5–20°C). Pelleted lettuce seed is primed, which widens the temperature range for germination and gets around part of this dormancy.
TRANSPLANTING for HEAD LETTUCE: Start seed in 128-cell trays 3–4 weeks ahead of planting out, barely covering it with vermiculite or fine soil. During germination, use shade and frequent misting if needed to keep trays below 75°F (24°C). Seedlings hardened off for at least 3–5 days before planting can take lows around 20°F (-7°C). Set iceberg, romaine and butterhead plants 10–12" apart in rows 15–18" apart, other types 8–10" apart in 12–18" rows, and mini heads as tight as 6" on a grid.
DIRECT SEEDING for BABY LEAF: Seed sprouts well in soil as cool as 40°F (4°C) but often poorly once it's over 75°F (24°C). Sow 4–6 seeds per inch in rows 2" or more apart, cover lightly to about 1/8" and firm gently. Water dry soil before sowing so it stays cool and moist for even germination.

HARVEST:

Head lettuce: cut at the base and leave the wrapper leaves on to absorb handling damage. Cutting every other plant lengthens the harvest, since the rest keep growing. Pack heads in layers with the cut ends facing away, then rinse off the sap and chill right away to avoid browning and wilting. Baby leaf: once leaves reach about 3–4", cut roughly 1" above the growing point, and clear away cut debris so regrowth stays clean.

STORAGE:

Store at 35–40°F (1–4°C) in high humidity, with no standing water. Head lettuce lasts 14–20 days, less for tender butterhead and oakleaf types and longer for lettuce grown slowly in cool weather. In cold weather, one-cut types can be held in the cooler for up to two weeks before being processed into salad mix.

MT0-30 SEEDS:

"MT0-30" is a seed-industry testing standard for Lettuce Mosaic Virus: it means a sample of at least 30,000 seeds was tested and no LMV was detected. Contact us if you need testing details for a specific variety.

DAYS TO MATURITY:

Head lettuce is counted from transplanting; baby leaf from direct sowing.

AVG. DIRECT SEEDING RATE:

Baby leaf at 60 seeds per foot: 1,000 seeds cover about 16', 1 oz. about 400' and 1 lb. about 6,400'.

TRANSPLANTS:

About 16,000 transplants per oz. on average.

SEED SPECS:

SEEDS/OZ.: about 17,800 on average.

PACKET:

500 seeds per packet unless noted.