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). Soil temperature should be kept higher than
5°C / 41°F to ensure good germination.
By our calculations, you should look at sowing Butterhead about 60 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Butterhead is a tender plant.
By our calculations, you should look at planting out Butterhead about 45 days before your last frost date.