Raised Bed for Vegetables a solution for toxic soil?

by Connie Griffin
(Gananoque, Ontario)

Hi: I have a huge black walnut tree in my back yard. My yard rock hard clay and is 60' wide and about 150' long to a sloped bank on the Gananoque River. I am thinking about putting in a raised bed to accomodate a vegetable garden. Unless I put vegetables in pots they currently die as a result of the toxins from the black walnut tree roots. Will a raised bed eliminate the toxins and allow me to grow vegetables? I love the shade and the tree other than it's toxins and the 20 + wheelbarrow loads of nuts each fall. Thanks, Connie


Doug says the raised bed will indeed be the solution until the roots from the tree invade the raised beds. And they will. So you're going to have to seal off the bottoms and sides of the raised beds with a heavy-duty landscape fabric to stop invading roots. And even then after a few years, I suspect you'll find tree roots penetrating this fabric.

At that time, you'll have to dig out the soil, whack back the roots, repair the liner and replace the soil.

But you should get quite a few years out of it if you makes sure to install the liner carefully so there are no openings and use a heavy-duty pro level fabric (not the el-cheapy stuff)

Good luck with these raised beds.