Try to aim for a seed spacing of at least
0.98 inches (2.5 cm) and sow at a depth of around
0.47 inches (1.2 cm). Soil temperature should be kept higher than
16°C / 61°F to ensure good germination.
By our calculations, you should look at sowing Dagger about 15 days after your last frost date.
As Dagger is half hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.