Sow at a depth of approx.
0.99 inches (2.54 cm) and aim for a distance of at least
2.97 inches (7.62 cm) between Pea plants. For optimal germination, soil temperature should be a minimum of
4°C / 39°F.
By our calculations, you should look at sowing Gradus about 35 days before your last frost date.
Gradus is half hardy, so ensure you wait until all danger of frost has passed in your area before considering planting outside.