Aim to sow 0.2 inches
(0.5 cm) deep and try to ensure a gap of at least 7.8 inches
(20.0 cm). Soil temperature should be kept higher than 10°C / 50°F
to ensure good germination.
By our calculations, you should look at sowing Solar Flashback Mix about 35 days before your last frost date.
As Solar Flashback Mix is half hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.