Sow at a depth of approx.
0.5 inches (1.27 cm) and aim for a distance of at least
1.95 inches (5.0 cm) between Garden nasturtium plants.
By our calculations, you should look at sowing Primrose Jewel about 14 days before your last frost date.
As Primrose Jewel is hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.