Sow
0.39 inches (1.0 cm) deep with a guideline distance of
11.7 inches (30.0 cm). Soil temperature should be kept higher than
20°C / 68°F to ensure good germination.
By our calculations, you should look at sowing Garden Party about 60 days before your last frost date.
As Garden Party is tender, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.