How to Prepare Your Plants for Freezing Temperatures
Please take a moment to read this great advice from Dan Gill at the LSU AgCenter.
Unless you are keeping them inside for the rest of the winter, move container plants back to their spots outside. Plants do not mind being moved in and out as needed through the winter.
For plants that you covered, remove or vent clear plastic covers on plants to prevent excessive heat buildup if the next day is sunny and mild. You do not need to completely remove the cover if it will freeze again the next night. You may leave plants covered with blankets, sheets or black plastic for several days without harming them, but eventually the covers will need to be removed so they can get light.
Pruning
Do not prune anything for a week or more after a freeze. It often takes a week or so for all of the damage to become evident.
Damaged growth on herbaceous or non-woody tropical plants, such as cannas, elephant ears, birds-of-paradise, begonias, impatiens, philodendron and gingers, may be pruned away back to living tissue. This pruning is optional, and is done more to neaten things up than to benefit the plants. However, if the damaged tissue is oozy, mushy, slimy and foul smelling, it should be removed.
If you don’t prune before, be sure to cut back or prune these herbaceous tropicals in spring after danger of freezes is past and before they make substantial new growth.
You may remove the damaged foliage from banana trees but do not cut back the trunk unless you can tell for sure that it has been killed. It will look brown, feel mushy, feel loose in the soil and will bleed a lot if punctured. The exception would be any banana trees that produced a bunch of fruit last year. They will not send up any more new growth, and should be cut to the ground to make room for new shoots that will come up this summer.
Generally, it’s a good idea to delay hard pruning of woody tropical plants, such as hibiscus, tibouchina, angel trumpet, croton, ixora, schefflera, copper plant and rubber tree, until new growth begins in the spring and you can more accurately determine which parts are alive and what is dead. Dead leaves on woody tropical plants can be picked off to make things look neater. If you can clearly determine what branches are dead on a woody plant you can prune them back. Try scratching the bark with your thumbnail. If the tissue underneath is green, it’s still alive. If the tissue is tan or brown the branch is dead. Start at the top and work your way down to see how far back the plant was killed.