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Wednesday - March 20, 2013

From: Ventura, CA
Region: California
Topic: Septic Systems, Trees
Title: Bald cypress knees in leachfield from Ventura CA
Answered by: Barbara Medford


Hey, I planted a seedling 20+ years ago which has turned out to be a 40'bald cypress that's now 40'. I'm a native southerner and would hate to cut it down but it's putting up knees in my septic system's leachfield. It's a good 90' from the tank itself. Are the roots in the leachfield necessarily a bad thing, feeding on that waste water?


According to this USDA Plant Profile MapTaxodium distichum (Bald cypress) is not even native to California, but since you have been growing it for 20 years and also since California is the world capital of plants that are native to somewhere else, we will not consider that as a problem. As you can see from the pictures from our Image Gallery below, the Bald Cypress happily puts up knees in just about any damp situation. Knees develop mostly in poorly drained sitations, which obviously a leachfield is. The fact that your leachfield is so far from the tree itself demonstrates vividly what we keep telling our visitors: that there is much more to a tree underground than is visible above ground.

So, obviously the tree is doing just fine. The question is, how is your leachfield doing? Since we know a lot more about tree roots than we do leachfields (which is zip) we will have to do a little research on whether you need to take any action. Turns out Mr. Smarty Plants has already answered a question on tree roots in leach fields. This article on Septic Plant Problems concerns trees that were deliberately planted on top of the leach field; the advice there was to cut down the trees and remove them. That's pretty harsh and your tree with the offending roots is 90 ft. away, for goodness sake.

Frankly, we think this is out of our expertise. We would recommend you have an expert in septic systems look at the situation. Obviously, you don't want to cut down the tree; perhaps cutting out the offending roots would suffice for a while, but you can bet the tree will send roots right back to its dinner table.


From the Image Gallery

Bald cypress
Taxodium distichum

Bald cypress
Taxodium distichum

Bald cypress
Taxodium distichum

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