Sow
0.23 inches (0.6 cm) deep with a guideline distance of
1.95 inches (5.0 cm). Soil temperature should be kept higher than
15°C / 59°F to ensure good germination.
By our calculations, you should look at sowing Burpee's happy days mix about 49 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Burpee's happy days mix is a half hardy plant.