They need mulch. We put a light mulch over the seedlings; now we must use a heavy one. Three inches of porous material will do a good job of keeping weeds down and the soil moist and cool.
When winter comes be ready with additional mulch. I like hay for this and apply it so that only the tops of the plants show right after a good frost. That keeps in the cold, retains moisture and prevents the heaving of alternate freezing and thawing.
Don't miss the pansies that appear from time to time through the winter. Whenever there is a thaw or a few sunny days, you'll be likely to find a brave little blossom or two. If those aren't enough for you, why not grow some just for winter blooming? The pansies I cherished most bloomed for me in February during a particularly cold winter. I started the seed in a flat in June and set out the little pansies in a cold frame. (An unheated greenhouse would have been better, if I had had one.) The plants took zero nights in their stride, with nothing but a mat of straw over the glass to protect them. In response to the lengthening days of February they budded, then bloomed their 4 -- inch velvety flowers. That cold frame was my morale builder; its mass of bright bloom set in a border of snow made my spirits rise every time I looked at it. Like strawberries in December, pansies are far more exciting in February than in May. Try that late winter pickup when you are so tired of cold and snow that you feel you just can't take another day of it.