I have an Atlanta client with a pair of large, spreading water oaks in his front yard. The roots, however, keep clogging his sewer line and his plumber wants to trench between the trees to replace the line. The client decided not to do that after consulting me about potential root system damage. He's had Roto Rooter out annually to unclog the pipe. His plumber told him that occasionally flushing copper sulphate down the pipe would also keep it clear.
It's my understanding that copper sulphate is basically a salt, which would likely desiccate the roots growing in the pipe. But what about the roots beyond? Does anyone have any information or experience with this practice? He doesn't want to harm the trees and will continue to rely on Roto Rooter if necessary. Thanks for the help.

Keep looking up, Tom

Reply to post by Tom Watson, on March 10, 2000 at 00:18:47:

Hi Tom

My neighbor had a 22" sugar maple that was making a career out of filling my sewer and my neighbors as well. For 4 years I rotorootered and copper sulfated twice per year; in other words, something happened about every three months to the roots in the pipe. In 4 years of both of us doing this, there was no appreciable change for the worse in the tree, so much so in fact, that my neighbor had the tree removed in frustration. Then we both replaced our sewer lines.

Looking at the stump after the last cut showed that there was no decernable change in the size of annual ring development, twig growth had been consistant, and the thing looked great actually. I think it had sufficient rooting area that the little loss and potential salt damage to the roots in the pipes was of no consequence.

Wayne

Reply to post by Tom Watson, on March 10, 2000 at 00:18:47:

A personal anecdote: I live in the foothills of the Sierra, amid a stand of Ponderosa pines. My 30+ yr old septic system got real slow, and the first outfit told me they needed to replace my drain field, requiring the removal of numerous large trees, etc.
After the shock sank in, I had another outfit search out the unknown layout of the drainfield and was told that copper sulfate might help.
It was recommended to put it into a distribution box downstream of the secondary tank, but there was no apparent such thing. So, I mixed up the crystals in hot water, to dissolve them as much as possible, then put them into the secondary tank. The darainage into the field improved, and it has remained adequate for a couple of years already.
There has been no obvious sign of a decline in health of the surrounding trees. Some of these trees are as large as 30"DBH. I don't know how far the salt migrated in the soil beyond the drainfield. I can only guess if there would be an accumulative effect with repeated use. The soil is a heavy clay born of basalt.

Reply to post by Tom Watson, on March 10, 2000 at 00:18:47:

Several years ago I was in a used book store looking at an old farmin hints book. One of the hints they had to keep tree roots out of sewer lines was to push a heavy copper wire into the sewer line. I understood that the copper would shed what ever chemical was needed to keep the roots out of the line. Seemed like a slow release chemical reaction along the lines of the rod in the water heater.

Someone who knows more about chemistry should be abel to give an explanation.

This would be a relatively inexpensive solution.

Tom

Reply to post by Tom Dunlap, on March 10, 2000 at 00:18:47:

Hmmm...That reminds me of the copper wire strung along the roof peak to control moss on the shingles. Or the copper used as a barrier to slugs and snails around seedlings. I guess elemental copper is toxic to lots of things. Now about copper nails in trees...?

Reply to post by Mark Goodwin, on March 10, 2000 at 18:53:36:

Mark,

Do you know if the copper wire works for moss and slugs?

I have heard about copper nails in trees too. I wonder if is a chemical reaction to the copper or a physical reaction to the nails being poked through the cambium!?

Tom

Reply to post by Tom Dunlap, on March 10, 2000 at 20:36:35:

Tom, I've only heard/read about it, but I'll try and put it to a test this year.(Not the tree nails!)

Reply to post by Tom Dunlap, on March 10, 2000 at 20:36:35:

Hi Tom,

It is a wives tale. Nails in the tree that is. Yes copper salts a phytotoxic but so are most zinc and iron
salts at high levels too. I have actually had to add copper sulphate to the sail in low levels one some trees
that had soil deficient in copper. Ordinary steel nails certainly seem to cause more discoloration than copper.

On the other hand I dread to think how many nails I have cut through and the tree has been healthy.

Mark