Try to aim for a seed spacing of at least
3.12 inches (8.0 cm) and sow at a depth of around
0.49 inches (1.25 cm). Soil temperature should be kept higher than
8°C / 46°F to ensure good germination.
By our calculations, you should look at sowing 7-green about 60 days before your last frost date.
Ensure that temperatures are mild (minimum night temperatures should be around 0°C / 32°F) and all chance of frost has passed before planting out, as 7-green is a half hardy plant.