So a little less than two weeks after sowing the winter rye grass seed in the greenhouse the first of the grass seed started popping up. That is with freezing temperatures every night sometimes as low as 9 degrees. The other patches grass, which was sown a month ago, but doesn't have a greenhouse, I haven't seen any signs of the grass growing yet. It isn't a surprise but it answers my question about how that grass would do since it was planted so late in the year. Temps in the greenhouse right now are 30 degrees warmer on a slightly overcast day right now.