With the recent cold snap many people are asking how to care for their damaged fruit trees. Here are a few snippets from the Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: June 1992. Reviewed: June 1994.
The first step in the pruning process is to wait until late spring or the summer following the winter the damage occurred (In Arizona, our last chance of frost is approximately mid-February). This will give you time to assess the damage. In addition, freeze-damaged trees occasionally put out a false start of new growth in the early spring which soon dies back. Delaying pruning until after this occurs will save you time and energy.
When pruning always remember to prune living wood, ideally at crotches, to ensure that you cut away all of the damage. In the case of young trees that have been banked, the tree may survive and put out a new top even if you have to cut away all the wood above the bank.
In very severe cases, a citrus tree may be damaged all the way to the ground. In such cases, the root area may still put out new growth and the tree may, in time, recover. However, if the original tree was a graft and the tree is killed off below the bud, any resulting new growth will be of the variety of the rootstock and not of the graft or scion. It will be up to you to decide whether to re-graft, allow the rootstock to continue growing or start again.
How to Prune Citrus Trees
1. Make a small wedge shaped cut on the underside of the branch just on the branch side of the stem collar. This will break the bark at that point and prevent a tear from running along the bark and stem tissue.
2. Somewhat farther along the branch, starting at the top of the branch cut all the way through the branch leaving a stub end.
3. Finally, make a third cut parallel to and just on the branch side of the of the stem collar to reduce the length of the stub as much as possible.