Try to plant in a location that enjoys full sun and remember to water moderately. Keep in mind when planting that Harlequin 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).
Growing Harlequin from seed
By our calculations, you should look at sowing Harlequin about 56 days before your last frost date.
Transplanting Harlequin
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Harlequin is a hardy plant.