Try to aim for a seed spacing of at least
0.98 inches (2.5 cm) and sow at a depth of around
0.23 inches (0.6 cm).
By our calculations, you should look at sowing Jubilee Gem about 7 days after your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Jubilee Gem is a half hardy plant.