Keep in mind when planting that Pacific purple is thought of as hardy, so this plant will grow or become dormant during the winter.
Soil temperature should be kept higher than
21°C / 70°F to ensure good germination.
By our calculations, you should look at sowing Pacific purple about 90 days before your last frost date.
As Pacific purple is hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.