Sow
0.04 inches (0.1 cm) deep with a guideline distance of
11.7 inches (30.0 cm). Soil temperature should be kept higher than
18°C / 64°F to ensure good germination.
By our calculations, you should look at sowing Duo about 56 days before your last frost date.
As Duo is half hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.