Determining the health of your trees is largely based on the amount of new growth each year. Observe the tips of the branches that are exposed (not shaded). A tree that grows less than 4 inches from the previous year is likely under stress and considered unhealthy.
Meristems are the part of the tree where new cells are formed and growth takes place. Apical meristems are at the branch tips. Growth here increases the canopy of the tree. New growth from these meristems is often identifiable by the color. The new twig emerging from the bud may be greener but the leaves are often a brighter shade as well. You’ll notice the leaves attached directly to these new stems rather than lateral branches. New growth may also look more compressed than growth from previous years.
Though evaluating the amount of growth can help you determine if your tree is healthy, it does not tell you what may be the cause of an unhealthy tree. The effects of stress accumulate year after year. A drought two years ago can have an impact on growth of a recovering tree. The root growth may have been stunted and roots could struggle to take in enough water to support the tree as temperatures rise. When possible, ensure trees are receiving water to a depth of 12 inches every couple of weeks during the summer either from rain or supplemental watering.
Cynthia Domenghini, Extension Agent
