You're lucky--you must have perfect conditions for them if you got purple allyssum to grow like that. It usually doesn't grow as well or as big as the white. It is an annual so I imagine it will eventually bloom itself out.

I grow the easter basket allyssum-- a mixture of colors white, pink, cream, and mauve. It reseeds and I usually end up with all the colors. Whether yours will come back dark purple, I don't know, but I'd say the chances are good

The purple bloomers will re-seed purple, though my experience with them says they don't reseed all that much. In my area, they only do well in the cooler parts of the year, but don't withstand much/any frost.

donnabaskets:

Strange that yours don't withstand frost. It is also what I read on the web and I was puzzled by it.

Mine come up in early spring and they do get frost. Quite a lot in fact and live through it. I know they sprout in cool temperatures and I always thought of them as very frost tolerant--HUH--strange, very strange how they react differently in your climate and mine.

I grew them extensively in coastal SC 8b for winter color all winter long. They handled frosts and freezing temperatures in that location, but may not where you live, donnabaskets. I used them in planting beds and in containers on a sunny porch.

Gosh, the winter bees and butterflies sure did love those sweet little flowers!

Dorie

Well, shoot! I love alyssum, but haven't grown it in years for the above reasons. Maybe I'll try again this year, just in case.