This winter we have experienced temperatures in the single digits that have caused cold injury to plants. You may have noticed your evergreen trees and shrubs have leaves that have turned brown or are even falling off. Cold damage occurs when ice forms inside the plant tissue and injures plant cells. This may have a drastic effect upon the entire plant or affect only a small part of the plant tissue and stems. Plants that are more exposed to the wind tend to be more susceptible to injury. We have seen this kind of damage on: Tea Olives, Hawthorns, Gardenias, Lorpetalum, Boxwoods, etc. We are also anticipating currently leafless shrubs will show signs of damage this spring.
So what can you do? First, while it may look better now if you prune off the dead leaves and twigs, you’ll be exposing undamaged lower growth to the threat of cold weather in March and April. Wait to prune until your plants start putting out new growth. Second, your trees and shrubs are going to need fertilization this spring. The trees and shrubs in your landscape are already nutrient starved as their greatest source of winter and spring food is raked or blown off each fall leaving the soil lacking the rich organic material their leaf decomposition creates. This winter, your evergreens in particular have faced the additional stress of brutally cold temperatures. Fertilization now helps in two ways: The organic material will help your trees and shrubs push new growth past the damaged tissue, and healthier plants are more able to recover from injury or stress.
Given the huge swings in temperature and the amount of precipitation we have gotten over the past year, not even the weatherman can predict what the spring and summer have in store for us.