Proper irrigation is an important part of tree establishment. The small amount of roots in the root ball needs frequent watering, so sprinkler heads or other irrigation pipes often are placed above the root ball.
But this can cause problems as the tree grows.
If the irrigation systems are left in place, the tree will produce roots in that area rather than growing outward. As these roots grow, expanding in girth, they can strangle or girdle the tree, cutting off the flow of water and nutrients. This can cause dieback in the canopy of the tree, jeopardize the stability of the tree or even kill it. And trying to reroute a pipe can damage roots.
To avoid this problem, place the irrigation pipe far enough away from the tree to allow for the expansion of the trunk to maturity. Check the system annually and move the emitters outward to promote uniform growth. Once the tree is established, usually one year for every caliper inch, place irrigation emitters at least half the distance between the dripline (the edge of the canopy) and the trunk of the tree.
This spring, check existing irrigation piping around growing trees in planting beds to avoid any potential problems. Consult your local irrigation specialist for options and alternatives if you have a problem that you cannot resolve on your own.
Robert Brudenell is a certified master arborist and owner of The Natural Way Inc.
