Recent cold fronts moving through Phoenix have caused widespread frost damage throughout the Valley — particularly in Ficus and Sissoo trees. If you’re noticing signs of frost damage in your trees, we have some tips for restoring their health.
Patience is key
Trees with frost damage will require time and patience to nurse back to health. If you wish to recover your tree, the key factor is to give it time and provide it with the appropriate amount of water consistent with normal growing needs. Though a tree may appear unsightly and heavily damaged above ground, its root systems are durable and likely remain healthy and ready for new growth. First, focus on the restoration and recovery of your tree. Once your tree has made its recovery, you can then focus on aesthetic pruning. It could take several seasons — but with the appropriate level of care — your tree can make a full recovery.
Caring for frost damaged trees
When the threat of frost has subsided and new growth has begun, its time to begin pruning. Start by doing a scratch test. To perform a scratch test, simply use your fingernail or a pocket knife on the trees smallest twigs and branches to determine the extent of the frost damage. If the wood is healthy, the tissue or flesh of the plant will reveal a green color. If you find brown or black tissue, this means the branch is dead. You will need to continue your scratch test on larger twigs and branches until you find where the green tissue begins. Once you identify where the healthy tissue begins, you will want to prune up to that point.
If you decide to prune your tree yourself, its critical that you be properly equipped. Having the right tools to prune your tree is important to the health of the plant material.
Limbs up to ½ inch in diameter can be pruned with hand pruners. Long-handled pruning loppers can handle limbs up to 1 inch in diameter, but a special pruning saw is needed for larger limbs. Hand pruners and loppers should be of the scissor or bypass type rather than the anvil type. Hedging shears or power hedge trimmers should not be used to prune trees because they will not be able to make proper cuts and will damage the tree.
It is a good idea to wear a long-sleeved shirt, long pants and closed shoes when pruning; additionally, wear safety glasses, a hat and gloves to help prevent an injury. Unless you are a trained tree worker, avoid using a ladder or climbing a tree to trim it. Most importantly, never attempt to prune a tree that is near a utility line!