Try to aim for a seed spacing of at least
5.85 inches (15.0 cm) and sow at a depth of around
0.0 inches (0.0 cm). Soil temperature should be kept higher than
20°C / 68°F to ensure good germination.
By our calculations, you should look at sowing Radiance about 28 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Radiance is a half hardy plant.
The botanical epithet is from the Latin bipinnatus meaning “staunch” or “like two small wings”.