Sow at a depth of approx.
0.39 inches (1.0 cm) and aim for a distance of at least
7.8 inches (20.0 cm) between Sweet pea plants. For optimal germination, soil temperature should be a minimum of
10°C / 50°F.
By our calculations, you should look at sowing Isabella Cochraint about 42 days before your last frost date.