Of what is the barrier concstructed?

It's the mesh stuff made to block weeds. Although water can get through, it's pretty impenetrable otherwise.

1. I don't think the mesh stuff would ever stop any rodent that I have ever met.

2. This is just a guess, but having observed just how tough tomatoes are (they are descended from a weed), I think they might just punch through your "barrier" or otherwise survive. Stay with them.

I wouldn't tear up the garden to remove it now but this fall when the bed is dormant I'd try to get as much of it as possible out. The problem is that it drains very slowly and if not perfectly level pools of water develop under the soil causing root rot.

For stopping weeds below raised beds a couple of layers of cardboard is often recommended as it decomposes within 1 season. For moles, voles, and gophers I have read where others have used hardware cloth - 1/2-3/4" metal liners with excellent results.

Dave

I have used hardware cloth in two beds for two seasons, all 5 beds have it now.
I don;t think the plastic cloth would bother a root system. Or a rodent. they are remarkably tough. Both of them.

I would have used plastic wire mesh, it is like plastic chicken wire. Doubt gophers would chew through it.
Wont rust, roots would grow right through it like it isn't there.

Here is a link that might be useful: Plastic Chicken mesh

Pretty sure that rodents can chew through plastic. Rabbits have chewed through my heavy netting.

My choice would be hardware cloth.

Cindy

The first year I had a raised bed we put landscape fabric at the bottom -- under all the soil. What a disaster!! The tomatoes and peppers didn't really grow at all. The veggies I had in containers did better. At the end of the year we dug out the bed and moved it -- the soil at the bottom was absolutely drenched. It couldn't' drain, and the plants suffered.

Now we use hardware cloth.

I'm a relatively new gardener, so take my humble opinion with a grain of salt, but I think that landscape cloth is pretty much the devil's work. We had it put down by our home's former owners all around the beds on the side of the house. The problem was that eventually you get a whole ecosystem of really rich material growing on top of it, but not blending through into natural soil layers like nature intended. Moreover, it DID stop most of the roots from growing through it, so the roots on top were spindly little things going all throughout the top of the cloth looking for a way down (and these are roots from big hardy bushes that couldnt get through). Then to make matters worse, the roots underneath the cloth had grown to press up against the cloth, creating weird air pockets under the cloth, which is terrible for the roots.

Long story short, I wouldnt touch the stuff with a ten foot pole. We put down chicken wire made of metal below our beds as a precaution. But anything, even nothing, has to be better than that cloth.

This thread explains much of what I have seen the last 3 years. Each year, everything starts out nice plants are green and growing well. When it comes time for fruit, my big beef is like a cherry tomato and the plants tend to peter out by Aug. I also have a black weed barrier about 10" down. Guess whats coming out next year!