keeping roots out of a garden bed

paradajky · December 10, 2023

Hi:

We dug out one of the garden beds, 10x18 ft, about 1.5-2ft deep yesterday. It was full of roots from the surrounding trees (fruit, pepper, palm, various groundcover, etc). We will not remove the trees, and don't have any better places for a bed at this time.

The bed is on a slope, and its bottom follows the angle, it does not cut into the hill like a terrace.

The bed was originally lined with the cheapest landscape fabric, and the gardener who did it overlapped each sheet by maybe an inch or two.

We are thinking of relining it better this time, but not sure whether to use a higher quality landscape fabric or a plastic sheet (6 mil is available locally; 14 mil pond liner is as well, but it is almost 8 times more expensive per sq ft).

Benefits of the fabric are that it is breathable to some degree and the quality one looks like it would keep roots out and last a while (we made grow bags with this stuff). However, we're concerned the roots will find their ways through the overlap, so possibly we could glue the overlap or do something like a 50% overlap of each sheet. Seems wasteful.

Therefore we're looking at the plastic sheeting, and the benefit is that it's large enough to cover the entire bed in one piece. I've read it's bad to use this as water can pool up. Is this a concern if we are on a slope? We could put a drainage pipe with holes that runs parallel at the lower edge and provides an exit for the water, but I'm not so sure that's necessary since the walls of the bed are porous.

If we can go with plastic sheeting, would the 6 mil be sufficient? The pond liners are either all pvc or ldpe reinforced with pvc, and I'm just more comfortable using ldpe with the constant contact to vegetables.

Thanks for sharing your thoughts.

December 10, 2023	#1
paradajky Tomatovillian™ Join Date: May 2021 Location: Coastal Southern CA Posts: 164	keeping roots out of a garden bed Hi: We dug out one of the garden beds, 10x18 ft, about 1.5-2ft deep yesterday. It was full of roots from the surrounding trees (fruit, pepper, palm, various groundcover, etc). We will not remove the trees, and don't have any better places for a bed at this time. The bed is on a slope, and its bottom follows the angle, it does not cut into the hill like a terrace. The bed was originally lined with the cheapest landscape fabric, and the gardener who did it overlapped each sheet by maybe an inch or two. We are thinking of relining it better this time, but not sure whether to use a higher quality landscape fabric or a plastic sheet (6 mil is available locally; 14 mil pond liner is as well, but it is almost 8 times more expensive per sq ft). Benefits of the fabric are that it is breathable to some degree and the quality one looks like it would keep roots out and last a while (we made grow bags with this stuff). However, we're concerned the roots will find their ways through the overlap, so possibly we could glue the overlap or do something like a 50% overlap of each sheet. Seems wasteful. Therefore we're looking at the plastic sheeting, and the benefit is that it's large enough to cover the entire bed in one piece. I've read it's bad to use this as water can pool up. Is this a concern if we are on a slope? We could put a drainage pipe with holes that runs parallel at the lower edge and provides an exit for the water, but I'm not so sure that's necessary since the walls of the bed are porous. If we can go with plastic sheeting, would the 6 mil be sufficient? The pond liners are either all pvc or ldpe reinforced with pvc, and I'm just more comfortable using ldpe with the constant contact to vegetables. Thanks for sharing your thoughts.