A fellow allotment person suggested I buy a a three-bay (6 metre) polytunnel like he'd just bought and installed, because it was only a £120, and worth every penny.
Our allotment is on the Romney Marshes of Kent. A small hurricane is merely a slight draught around here. The said polytunnel wasn't there two weeks later, and I know that he'd planted it a foot into the ground, pegged it, and laid slabs inside and out, just to make sure.
The "make sure" bit didn't happen. Failed miserably. However, we do have a large polytunnel on site, that has individual plots inside that you can rent. This has been up for well over a decade, and is completely intact. I reckon it depends where you are, how sheltered it is, and how much you're willing to pay.
