Try to aim for a seed spacing of at least
5.85 inches (15.0 cm) and sow at a depth of around
0.49 inches (1.25 cm). For optimal germination, soil temperature should be a minimum of
5°C / 41°F.
By our calculations, you should look at sowing Red Iceberg about 60 days before your last frost date.
Red Iceberg is tender, so ensure you wait until all danger of frost has passed in your area before considering planting outside.
By our calculations, you should look at planting out Red Iceberg about 45 days before your last frost date.