Sow at a depth of approx.
1.17 inches (3.0 cm) and aim for a distance of at least
4.94 feet (1.52 metres) between Pumpkin plants. Soil temperature should be kept higher than
21°C / 70°F to ensure good germination.
By our calculations, you should look at sowing Mammoth about 14 days before your last frost date.
As Mammoth is hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.