Try to aim for a seed spacing of at least
1.95 inches (5.0 cm) and sow at a depth of around
0.98 inches (2.5 cm). Soil temperature should be kept higher than
13°C / 55°F to ensure good germination.
By our calculations, you should look at sowing Yellow Potato Onion about 28 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Yellow Potato Onion is a very hardy plant.