Red Iceberg
Lettuce
🌱 70d to harvest
Rosette
Crisp as freshly fallen snow, Red Iceberg forms tight, rounded heads with a dramatic blush of deep ruby to wine-red at the outer …
Crop Dates
| Milestone | Date |
|---|---|
| Start Indoors | Mar 28th |
| Last Frost | Apr 25th |
| Transplant / Sow Outdoors | Apr 25th |
| Harvest Begins | Jul 4th |
| Harvest Ends | Oct 16th |
Crop Details
| Trait | Value |
|---|---|
| Days to Maturity | 70 |
| Sun Requirements | Full Sun |
| Growth Habit | Rosette |
| Support Needed | None |
| Planting Depth | Normal |
| Germination Temp (°F) | 70 |
| Min Soil Temp (°F) | 40 |
| Min Night Temp (°F) | 30 |
| Harden Off (days) | 6 |
Recommended Companions
Frequently Asked Questions
What pest or disease most commonly affects Lactuca sativa (iceberg lettuce), and how can I manage it?
A frequent issue is downy mildew and tip burn-like stress, often triggered by cool-wet conditions and inconsistent moisture. Improve airflow with wider spacing, avoid wetting the leaves when watering, and remove the worst leaves early to slow spread. If mildew appears, use a labeled fungicide for lettuce/downy mildew and keep the soil evenly moist (not soggy) to reduce stress-related damage.
How often should I water Lactuca sativa during the main growing phase?
During head formation (after plants establish), keep the soil consistently moist but not waterlogged—about 1–2 inches of water per week depending on heat and soil type. Water deeply when the top 1 inch of soil starts to dry, because lettuce heads can become bitter or loose if moisture swings. In hot weather, you may need brief, more frequent watering to maintain even moisture.
How do I know when my red iceberg lettuce (Lactuca sativa) is ready to harvest?
Harvest at about 70 days when heads feel firm and have filled out, with crisp outer leaves and minimal leaf floppiness. Use the “gentle squeeze” test—if the head compresses easily, give it a few more days. Cut the head at the base early in the day for the best crispness, and don’t wait until leaves start to yellow heavily at the center.