Most municipalities require a tree protection zone, usually some sort of fencing around the tree to protect the tree and its root system. I have reviewed hundreds of these over the years, and can only recall one that actually “protected” the tree 100%.
Most TPZs consist of cyclone fence panels erected at the dripline of said tree, the soils outside the fence being fair game for whatever activity an excavator, bulldozer, trenching machine or cement truck can muster up. And to add insult to injury, if the plan calls for underground utilities to be installed inside the TPZ, down comes the panel, and as a feel good measure, having an arborist cutting the roots to facilitate this travesty…
This is NOT protecting the tree at all, it just looks good on paper!
Imagine if you asked me to protect your house and its contents while you went on vacation. Now when you returned from your trip, you discovered that I threw a rager party, and completely trashed your living room. You would probably ask what was I thinking when I did that. My reply was “Dude, I only trashed 15% of your house, chill out.” You’d be pretty steamed, I bet.
When you “protect” something, that entails keeping it from harm, not protecting it a little bit. That would be more like a tree compromise zone, wouldn’t it?
A tree’s roots don’t always follow the rules, or get the memo that they can’t roam outside the dripline whenever they darn well please, and they often do.
My rules for protection are as follows:
- Test dig whenever you can. An air spade is the way to go, but a shovel is a whole lot cheaper.
- Twice dripline is 1000 times better than a fence set up around the dripline.
- Discuss with EVERYONE even remotely involved with the project the importance of not screwing up the root system with activities like trenching, filling, compacting, raising the grade, washing out cement mixers, cutting roots, etc.
- Have this discussion BEFORE the developer, contractor, builder, subs, plumbers even bid the project to eliminate any confusion regarding the importance of your commitment to protect your tree.
- Go under, around or over roots always, not just whenever possible, because nothing is impossible.
If you cut 1% of your tree roots you stand about a 1% chance of killing your tree, and if you cut off 100% of your tree roots, you will kill your tree 100% of the time. Root systems are usually invisible being underground and all, so dig baby dig, and find out where the real “protection” zone shall be placed!
