Shhhh! I know it's winter and you know it's winter but my baby lettuce plants don't know. And that's the way I like it.
Truth is, I accidentally discovered that if I sow my lettuce seeds in the fall, they'll sprout, somehow magically survive the killing frosts and then grow happily under their cozy blanket of snow before providing an early harvest of delectable leaves in the springtime. These little guys easily doubled in size under the snow despite the sub-zero temperatures in December and January!
Easy-peasy gardening, gotta love it.