I have had one of the small ones for 3 years and I am already on the second
plastic covering. To be fair Gardmans were very good about sending a
replacement when I complained that the zips were splitting away from the
plastic. Now I put bungees around the whole thing to stop the wind billowing
it out and put small paving slabs in the bottom to stabilise it and absorb
some warmth during the day. It has enabled me to start my tomatoes off well
enough but I can't wait for the day when I havce a proper
greenhouse/poly-tunnel.