Look to ensure a distance
11.7 inches (30.0 cm) between seeds when sowing - bury at a depth of at least
5.85 inches (15.0 cm) deep.
By our calculations, you should look at sowing Dark Red Norland about 14 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Dark Red Norland is a tender plant.