If it gets in the teens it will burn them some, we were down to *21 a few days ago and it did not effect the seedlings. The cold effects the older plants more than the babies because of the amount of foliage that frost can cover. Frost is what burns not the cold tempts, until it gets in the teens and stays for several days like last winter. You should have no problem blooming seedlings in one year if you get them in the ground before Sept. 15, I will see 75 to 80% of these bloom in 2015. One other thing, I do not mulch anything here, I want the ground to warm back up fast after a cold spell to start growth again, the mulch slows the warming.
