Both my neighbours have poplar trees one has been cut they are both on each side of my house. I have suckers running everywhere there are damaging my yard and I fear that they could damage my foundation of my house. I can't use chemicals we are on a well system and septic system. I need a safe solution that is environmentally green.

You can't kill the feeder roots without killing your neighbor's tree.

Where is your well? Are the poplar's root getting in your well or septic? Bummer... Sounds like poplars shouldn't be so popular. Poplars apparently are notorious for suckering. How many poplars are there? Damage to neighboring trees by systemic herbicide use might be possible if there is root grafting going on, but is that a bad idea if they are poplars? You might have to buy a few of your neighbor's poplar trees, but it might be worth it. Are they planted or native grown?

Click here for great information on exactly this problem at a site apparently written by a smart dude from NDSU.

Consider installing a root barrier, like a pool or a 6 inch thick driveway. Kidding aside, you might have to install a root barrier. Look in your garden store for a fabric like material - some are impregnated with herbicides - that are meant for this use. Click here, here and here for examples.

Another non-chemical weed control method is called "tarping" Chop/prune the suckers as low as you can get them, and cover the stumps with thick plastic tarps - clear or black tarps? Try dark first - and stake them down, or weigh them down with dirt. Leave them down for months. Hopefully after a few months, the suckers will stop growing. I'm not sure how stubborn poplars are, though. This works well on iceplant.

The point is persistence. Is it possible to constantly, vigilantly, cut the suckers down every time they sprout? I would give it up, if you cut me down all the time.

The drinking well?. well, that's tricky. Is your well in good shape? Is it a public well? What is the current water table level? What is your soil type? If all your conditions are right - well is secure, water table not too shallow, clayey soil, well protection guidelines followed. Then I think it would be okay to use, on the suckers, a groundwater safe, wellhead protection plan approved, systemic herbicide by the cut stump, or cut and spray regrowth treatment methods. These and other methods might be used on a full grown tree. Follow the label's directions.

I actually read a scientific article where research on a poplar farm found that the farm's poplars' roots overlapped quite a bit, but no root grafting occurred. Sooo, it might be safe to use herbicides on poplar suckers without killing the neighbors' poplars, Butttt JKT may have experience worth listening to.