This winter, I'd like to purchase bare-root tree seedlings, which are shipped by mail in April. I'd like to plant them outside in large pots, but I'm concerned about the roots freezing, or other cold-related damage.
Should I keep these seedlings indoors until the nighttime low temperature passes some threshold? For example, should I keep the seedlings in a refrigerator until the nights tend to be above freezing? I'm in zone 5, so the April nights tend to be in the 20F range, and the days in the 40-50F range.