The heat in July and August presents a good opportunity to do any necessary oak tree pruning.
The rainfall of recent weeks has provided a refreshing summer break for us and our shade trees. And while we return to a more normal hot-dry weather pattern this week, one bright side is that the heat in July and August presents a good opportunity to do any necessary oak tree pruning.
Oak wilt disease always limits pruning season for live oaks and red oaks. But the form of fungus that spreads the disease (and the beetle that transports the spores of that fungus) are nearly non-existent in the latter half of summer — providing a brief pruning window over the next few weeks.
Although oak wilt slows down in summer, never let your guard down. When pruning oaks, always follow these rules to ensure proper pruning and prevent oak wilt:
- Large branches (greater than 1 inch) should be undercut to minimize additional damage and help the wound heal faster.
- To promote healthy wood and minimize damage, only remove dead, damaged, diseased and dangerous branches, especially in summer. For drought-stressed trees, avoid excessive pruning and leave some low branches to shade the trunk.
- If early training has not been possible, reducing the crown of the tree will prevent it from interfering with traffic, power lines or other structures. Never cut off more than 25 percent of a tree in a single year, and remember that young trees compartmentalize, or seal against decay better than old trees. In many cases, the only alternative for a tree that has outgrown its site is to replace it with a smaller-growing variety.
- ONLY oaks require paint on fresh wounds. Any oil or latex based paint is appropriate. Be creative. Use different colors. Mix and match with the house.
- Always keep yours tools sharp and clean them with some type of fungicide. I suggest Lysol (either original or lemon scent is fine).
Just keep in mind that if you miss the brief opportunity this month, winter is the best time for oak pruning. In fact, winter is normally the best time to prune any tree — except for those like redbud and Texas mountain laurel that flower on new wood in early spring.
Consult with a certified or licensed arborist before doing any major pruning and follow their recommendations. They can help identify oak wilt and other issues like hypoxylon canker that can affect stressed trees.
Find certified arborists through the International Society of Arboriculture. Consult the City of San Antonio’s Development Services to locate licensed arborists.
