Sow
0.49 inches (1.25 cm) deep with a guideline distance of
5.85 inches (15.0 cm). Soil temperature should be kept higher than
5°C / 41°F to ensure good germination.
By our calculations, you should look at sowing Green Grand Rapids Tropicana about 53 days before your last frost date.
As Green Grand Rapids Tropicana is tender, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.