Are they still in their jugs? If so you could plant out in small clumps. No need to thin.

Some are in jugs, some I potted up as clumps already. Glad to hear there is no need to thin! I’ll probably always winter sow sweet alyssum from now on because it’s so easy. Thanks, floral.

Yeah, I did the same and couldn't believe how well it worked and how much money it saves, since I expected to plan many dozens. They started blooming in the jug.