SproutSmart
SproutSmart Intelligent Garden Sowing

Iceberg

Lettuce
Botanical illustration of Iceberg
🌱 70d to harvest Rosette

Crisp as freshly fallen snow, Iceberg forms tight, pale-green heads with a cool, watery crunch that practically sings with every …

Planting Schedule

Add Iceberg to your garden to build a schedule and get reminders.

Crop Dates

MilestoneDate
Start IndoorsDec 4th
Last FrostJan 1st
Transplant / Sow OutdoorsDec 25th
Harvest BeginsMar 5th
Harvest EndsDec 31st

Crop Details

TraitValue
Days to Maturity70
Sun RequirementsPart SunPartial sun
Growth HabitRosette
Support NeededNone
Planting DepthNormal
Germination Temp (°F)65
Min Soil Temp (°F)40
Min Night Temp (°F)35
Harden Off (days)6

Frequently Asked Questions


What is a common disease problem for Lactuca sativa (iceberg lettuce) and how can I prevent it?
Leaf lettuce/iceberg commonly suffers from downy mildew (often showing pale yellow patches on the upper leaves with gray-purple growth underneath). Avoid overhead watering, keep seedlings spaced for airflow, and remove affected outer leaves early to slow spread. If conditions stay cool and damp, switch to a labeled downy-mildew treatment for leafy greens and keep the beds mulched to reduce splashback.
How often should I water iceberg lettuce during its main growing phase?
During the 45–70 days toward maturity, water to keep soil evenly moist 2–3 in. deep—aim for consistent moisture rather than letting it dry out between waterings. In warm spells, this often means watering every 2–4 days, but adjust so the soil never dries out fully; in cooler weather you may water weekly. If lettuce gets too dry, heads may not tighten well and edges can turn bitter.
How do I tell when iceberg lettuce (Lactuca sativa) is ready to harvest?
Harvest when the head feels firm and compact when gently squeezed, with leaves tightly layered and no loose, open center. Typical timing is about 70 days from sowing, but focus on head firmness and size rather than the calendar alone. Cut the head at the base in the morning for crisp leaves, and pick before prolonged heat that can cause loosening.
Botanical illustration of Iceberg

Crisp as freshly fallen snow, Iceberg forms tight, pale-green heads with a cool, watery crunch that practically sings with every bite. The leaves are thick and shingled, holding their snap through harvest and storage, making this crisphead a dependable centerpiece for fresh salads and bright, refreshing garnishes. Grow Iceberg for a classic, garden-grown crunch at about 70 days—clean, sturdy, and beautifully uniform from row to row.

Sowing Tips

Transplant Conditions

Wait until soil reaches 40°F and nights stay above 35°F before moving outdoors. Harden off for 6 days first.

Expert Note

For crisp heads like Iceberg, keep soil consistently moist and avoid heat stress—cool conditions produce the densest heads.