Recently, Mike, a landscape contractor, asked about obtaining containerized water oaks. However, let me share some information about water oaks.

When I was starting out in professional forestry, I was a service forester in an urbanizing county in Virginia. My job was to address the issues surrounding urban forestry, a new theme in in forestry during the 1990’s. Nothing I learned in college prepared me for this new area of forest management. One of the questions I frequently encountered was: What is the fastest growing tree for my landscape? One of the facts I learned in urban forestry was to avoid planting fast growing trees because they would be short lived and become maintenance headaches. Fast growing trees tend to have weak wood so broken branches and tops would require heavy clean-up.

One of my favorite recommendations at that time was to advise homeowners to plant water oaks because they are oaks trees with a fast growth rate. My reasoning was that the water oak would be a good compromise between growth and longevity.

Since that time especially after being a Horticulture Agent in Beauregard Parish, LA, I have learned that water oaks are the “teenagers of oaks” in that they have “issues”.

According to Clemson (SC) Cooperative Extension writers Debbie Shaughnessy and Bob Polomski, water oaks have these problems, “It is more weak-wooded than most oaks and prone to damage from wind, snow and ice. It does not resist decay well, and damaged wood will begin to decay and decline. Trunks often rot by the time a water oak is 50 years old. Shallow, spreading root systems compete for water and nutrients in the soil, causing problems with grass or other plants planted beneath a water oak. In warmer climates leaves drop all winter, making raking a constant task.”

I can affirm the observations of Shaughnessy and Polomski by virtue of site visits with homeowners. Large water oaks tend to have broken branches and obvious cavities. When these compromised trees are near homes, improvements, and parking areas, I consider them to be hazard trees and recommend their removal.

Still, water oaks can be good shade trees in the first 30 or 40 years. Shaughnessy and Polomski make these recommendations, “Train this tree to a central trunk, pruning to keep the main branches spaced 2 feet or more apart. Prune regularly to avoid making large pruning wounds that may cause decay. Lower branches droop as trees grow older. Prune as needed for clearance.”

If you have a younger water oak, enjoy it while it is healthy and robust. As the tree ages, keep an eye on it for damage which will likely be a site for decay. If you have concerns about your water oak, contact your County Agent or Extension Forester and ask for a site visit to see if your aged water oak is becoming a hazard tree to your home.

When choosing an oak tree to plant, consider consulting a publication from the LSU AgCenter, “Native Tree Growing Guide for Louisiana.” This document suggests these oaks for landscape plantings:

• Live oak
• Nuttall oak
• Cherrybark oak
• Shumard oak.

The Louisiana Super Plant program also recommends an oak worthy of consideration, and it is the willow oak. There are enough oaks for selection to replace any failed water oak in the landscape.

The Area Extension Horticulture Agent for Beauregard, Grant, LaSalle, Rapides, and Vernon Parishes is Keith Hawkins, 337-463-7006. His email address is: khawkins@agcenter.lsu.edu.

If you want to contact Working in the Landscape, please send your questions and pictures to Keith Hawkins, Area Horticulture Agent (AHA), 337-463-7006 or khawkins@agcenter.lsu.edu. Also, you can be on the “commercial horticulture” email list by emailing your request to the address above.

“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”

A large water oak with damage from a fallen branch. Photo: Chattanooga Arborist.

Old water oaks are susceptible to storm damage. Photo: Peggy Sanford.