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.
One of the more common means of water watering trees is the use of soaker hoses. Soaker hoses are notorious for non-uniform watering. On small trees, circling the tree several times with the soaker hose will even out the amount of water applied but this isn’t practical for larger trees. On larger trees, hooking both the beginning and the end of the soaker hose to a Y-adapter helps equalize the pressure and therefore provide a more uniform watering. The specific parts you need include the soaker hose, Y-adapter and female to female connector.
The soaker hose can circle the trunk at a distance within the dripline of the tree but at least one-half the distance to the dripline. The dripline of the tree is outermost reach of the branches.
Soil should be wet at least 12 inches deep as 80% of a tree’s roots are in the top foot of soil. Use a metal rod, wooden dowel, electric fence post or something similar to check depth. Dry soil is much harder to push through than wet and your probe will stop when it hits dry soil. How long it takes water to reach a 12 inch depth varies depending on the rate of water flow and soil. Record the amount of time it takes to reach 12 inches the first time the tree is watered. After that, simply water for that same amount of time.
Alicia Boor is the Agriculture and Natural Resources agent with K-State Research and Extension – Cottonwood District. Contact her by email at aboor@ksu.edu or call 620-793-1910.
