1)roots touching the inside of the pots will freeze during all-night frosts. A couple of hours here and there no biggy.

2)not too late to plant large plants when most roots are inches or more below soil surface, as long as ground is workable and not muddy.

3)whatever would hold the straw from blowing away, use that instead as cover. Don't let them get bone dry or let heavy rains soak the pot soil.

4)heated garage too mild and may confuse plants; 40-50 degrees is fine.

If it's too cold for a particular kind of plant a few hours is in fact all it takes to kill the affected roots.

The ceanothus should not be out in the 20s F. (or less) in pots. The maples may not care, depending on what kind they are. Sometimes Japanese maples can be a little tender in containers - there are three levels of damage to container plants, loss of new roots, loss of old roots and loss of top growth. The first listed is the first to go, the last listed the last. Much of the root system can be toast without the top showing it, until the growing season starts and then top growth may be stunted by the reduction of the root system.

All should get planted out as soon as possible. The ceanothus is a popular, comparatively hardy and locally successful type (probably correctly called 'Skylark') so planted in suitable sunny, well-drained situation and mulched well immediately afterward it may not be bothered by being planted during winter. And benefit from getting out of the pots.

If these have had damage to the outermost, newest roots that may become apparent when the pots come off at planting time (or if you check them beforehand). Intact, healthy young roots are light in color and fresh-looking, firm in consistency.

This post was edited by bboy on Thu, Jan 3, 13 at 12:47