That's the trick with the mini-greenhouses, how to hold them down in winds. Mine came with four-corner cord material and anchors you drive into the soil. I haven't even used mine yet (it is just for starting seedlings) but when I set it up in January, I will have two corners sitting near my landscape. I will use the cord/ground-anchors for those two corners (I actually double-up, so will have two anchors per corner). The other two corners are on the patio and I have a heavy bench along one side that I will tie a cord to and then have a large, heavy pot on the other corner that I will attach a cord to. Last year I had no trouble with this greenhouse moving.
