Aim to sow
0.98 inches (2.5 cm) deep and try to ensure a gap of at least
1.95 inches (5.0 cm). Soil temperature should be kept higher than
13°C / 55°F to ensure good germination.
By our calculations, you should look at sowing Amethyst about 28 days before your last frost date.
As Amethyst is very hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.