Keep in mind when planting that Blue Bouquet is thought of as hardy, so it can be safe to leave outdoors for the majority of winter (although if in doubt, using a row cover is often a good idea).
By our calculations, you should look at sowing Blue Bouquet about 63 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Blue Bouquet is a hardy plant.