Care of Freeze-Injured Citrus Trees
This week, Northwest Florida is once again receiving some bitter cold temperatures. The freezing weather two weeks ago resulted in some cold damage to some local citrus trees. Cold injured citrus trees can take a while to become evident.
What appears to be damage will not always be permanent. Never be in a hurry to remove cold injured tissue from a citrus tree. Citrus, especially Satsuma, can be very resilient and will often re-sprout on injured tissue. Pruning before this can happen can remove fruit producing branches. Leaves on a freeze-damaged citrus tree will be hard and brittle.
If freeze damage is severe, the leaves will collapse, dry out and fall from the tree. It’s normal for leaves to take on a wilted or drooping appearance during periods of low temperatures. Don’t confuse this with freeze damage. Frozen leaves will not be wilted – they will be hard and brittle. Freeze damage can also cause the trunk and larger branches to split and the bark to become loose. Twigs and branches may continue to die for up to two years following a severe freeze.
Unless the soil becomes dry, be careful to not water cold injured citrus trees during warm periods that often follow freezes. This will delay the tree’s growth and keep the tree in a more dormant state. However, it is important to not let citrus trees go totally dry, because this will increase freeze damage. Later on, if you see that the damaged tree is putting on new growth, it’s okay to give it a little water.
It is best to not prune or fertilize citrus trees during fall and winter.Delay pruning of damaged limbs until late spring or summer because it’s difficult to determine the extent of damage until spring growth takes place. Pruning also may encourage new tender growth during the cold season.
If it appears that you’ve lost half the tree in a freeze, you’ll only need to apply about half as much fertilizer. If you have the situation where many leaves were lost but twigs and branches were not injured, you’ll need to slightly increase the amount of fertilizer. Fertilization should begin after new growth has occurred come spring. It’s a good idea to make frequent light applications rather than one heavy application.
Fertilizing your lawn during fall and winter may not only be damaging to your lawn but it can potentially cause cold injury to your citrus trees, as well. The roots on trees (including citrus) extend two to three times beyond the tree’s branches. As a result, citrus tree roots grow out into the lawn. Tree roots in the lawn are shallow. So, late applications of lawn fertilizer will impact your citrus trees as well. Your lawn and citrus needs ample time to use the fertilizer but yet still have time to go dormant before cold weather arrives.