How Long Will Scrub Oaks Last in the Ground As Fence Posts?

Installation

• Scrub oak grows in grassy, dry regions. Fences constructed from scrub oak are usually pragmatic. They demarcate grazing areas or provide a boundary between roads and homes. Fence posts are interred at a depth of one-third their height. Their close contact with ground moisture increases the likelihood that they will disintegrate before other portions of fence. The rate of disintegration is dependent upon the overall climate and the age of the wood.

Environmental Conditions

• Scrub oaks are thick, heavy trees with trunks up to 15 feet in diameter and heights up to 30 feet. They grow in arid regions and are resistant to drought. Excess moisture, however, leads to root rot and wood diseases. Older scrub oaks, at times, fall victim to heart rot, which develops in the tree's interior wood, normally the strongest part of the tree. Posts exhibiting heart rot, discoloration and a spongy texture will not last as long as healthy wood. Root rot affects living trees but can also weaken a post's integrity and lead to an early demise. Inspect the wood for damage before installing fence posts.Scrub oak, also called Rocky Mountain oak, gambel oak and Utah white oak, has a high resistance to fungus and rot. In dry environments it can remain in place for up to 20 years. In highly humid climates, or areas with termite activity, the posts will not last as long.

Rot Resistance

• The weakest portion of tree wood is sapwood, the outer portion of the trunk just beneath the bark. The portion with the greatest resistance to fungus and rot lies in the center of a tree's trunk. This wood, the heartwood, has natural resistance to damage. Choose split-fence posts or those sawed from large trees; they contain greater amounts of heartwood than other posts.

Considerations

• Lengthen the life of a scrub oak fence by coating the posts with sealants or stains before installation. Water repellent sealants are effective only when used on above-ground portions of posts. They provide little, if any, protection against underground moisture. Most water repellents contain fungicides and pesticides. Take precautions when using these repellents near vegetable gardens, flower beds and garden soil.