Look to ensure a distance
11.7 inches (30.0 cm) between Snowy Apparition seeds when sowing to make sure your seedlings have enough space.
By our calculations, you should look at sowing Snowy Apparition about 42 days before your last frost date.
As Snowy Apparition is hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.