Sow at a depth of approx.
0.25 inches (0.64 cm) and aim for a distance of at least
5.85 inches (15.0 cm) between Lettuce plants. Soil temperature should be kept higher than
5°C / 41°F to ensure good germination.
By our calculations, you should look at sowing Iceberg about 60 days before your last frost date.
As Iceberg is tender, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.
By our calculations, you should look at planting out Iceberg about 45 days before your last frost date.