Well, 8 feet is the recommended height to keep deer out. Many on these forums install an electric fence for that purpose too. And if you have burrowing critters, it's generally recommended to sink the fencing well into the ground and L it toward the outside of the garden to prevent them from digging underneath.

Human critters? The electric fence plus a gate that locks MIGHT do it. :)

I think it has to a wire type. Like chicken wire ,At least the lower couple of feet plus anther foot or so buryed . This will keep rabbits , maybe beavers off. The top part can be plastic to keep deers out. With deers, it has to be about 6 foot tall.

Once I installed All plastic. It worked for a while then rabbits made holes and got in. I sealed the holes then they chewed the plastic an got in. So finally I ended up finishing the lower part by chicken wire.

Why don't you ask the others in the community garden what works for them?
As for the humans, you could put up a sign saying that it is an experimental garden being fertilized by human feces or urine! ;) That aughta keep them away! LOL

The only thing that will work for rabbits is wire fence, with the bottom buried to prevent digging. Deer will jump fences shorter than 8 feet, though my 5 strand electric fence seemed to keep out the deer and the groundhogs. It was funny to watch a deer cut through my yard and give my garden a wide berth. I suspect she got zapped earlier.
Squirrels and chipmunks you just have to learn to live with, unless you want to completely enclose your garden (including the top) because they will climb.

Thanks to all for your great advice. At the garden site there's a very wide assortment of ideas being tried. Some don't have any fencing (although there's not too many of those), some use non-fencing (I've seen some with tin plates, some use natural fragrances, others use scarecrows, and still others use fishing line, oh and I even saw one fence made out of playing cards), most do have fencing from wooden to metal to rope with electrical also included. And that's just what comes to my immediate recollection. The site's management says fencing is highly recommened, but not required. The general word seems to be to get around the pests - plant more than you need and be ready to share.

Wolverine summed it up pretty good, I think.

Then, it depend how your plot is situated in the community. If it is somewhere in the middle, you are partly shielded. But if it is on the edge then you have to take rabbits seriously. For deers the bells and vessels, old CDs, etc might work but not for Mr. Vabbit...haha