Try to aim for a seed spacing of at least
11.7 inches (30.0 cm) and sow at a depth of around
0.12 inches (0.32 cm). For optimal germination, soil temperature should be a minimum of
7°C / 45°F.
By our calculations, you should look at sowing Polyphant about 56 days before your last frost date.
Polyphant is hardy, so ensure you wait until all danger of frost has passed in your area before considering planting outside.