SproutSmart
SproutSmart Intelligent Garden Sowing

Great Lakes

Lettuce

Planting Schedule

Add Great Lakes to your garden to build a schedule and get reminders.
Botanical illustration of Great Lakes
70d to harvest

Crisp as fresh-cut glass, Great Lakes lettuce forms a dense, uniform head with a cool, sweet snap and a clean, refreshing bite. The leaves are thick and sturdy—deep green to blue-green on the outside, pale and buttery within—holding their crunch beautifully in the garden and on the table. Ideal for crisp salads and elegant platters, Great Lakes is a crisphead favorite for gardeners who want dependable, head-forming performance at about 70 days.

Crop Dates

MilestoneDate
Start IndoorsMar 11th
Last FrostApr 1st
Transplant / Sow OutdoorsApr 1st
Harvest BeginsJun 10th
Harvest EndsNov 5th

Crop Details

TraitValue
Days to Maturity70
Sun RequirementsFull SunFull sun
Growth HabitRosette
Support NeededNone
Planting DepthSurface
Germination Temp (°F)45
Min Soil Temp (°F)40
Min Night Temp (°F)32
Harden Off (days)6

Frequently Asked Questions


What pest or disease is most likely on Lactuca sativa (iceberg-type lettuce) and how do I treat it?
Iceberg lettuce (Lactuca sativa) is especially prone to downy mildew (often seen as pale yellow patches on leaf tops with fuzzy gray-purple growth underneath). Improve airflow by spacing plants and water the soil (not the leaves), then remove badly infected leaves immediately to slow spread. If it keeps recurring, treat early with a labeled fungicide for downy mildew on edible greens, following the product’s waiting period before harvest.
How can I tell when Great Lakes (Lactuca sativa) is ready to harvest?
Harvest when heads feel firm and reach about full size for your planting spacing; at 70 days from sowing or transplanting, timing typically lines up with head firmness. The outer leaves should be crisp and green, with no significant bolting (flowering stalk) starting in the center. Cut the head at the base with a sharp knife in the morning for best texture.
Botanical illustration of Great Lakes

Crisp as fresh-cut glass, Great Lakes lettuce forms a dense, uniform head with a cool, sweet snap and a clean, refreshing bite. The leaves are thick and sturdy—deep green to blue-green on the outside, pale and buttery within—holding their crunch beautifully in the garden and on the table. Ideal for crisp salads and elegant platters, Great Lakes is a crisphead favorite for gardeners who want dependable, head-forming performance at about 70 days.