Not sure what kind of greenhouse you have, but I used to have a small wooden greenhouse that I covered with builders plastic each year. I would pull the plastic up from the back, across the top, and then down the front, pull it under the frame in the front and back and pile soil over the plastic ends. On the sides I put heavy duty duct tape over the plastic and then stapled it to the wooden frame with 1/2 in staples. The sides were pulled under and soil piled onto them, too. It ripped one year from wind but the plastic was old and weak when I bought it. The hoop house that I have now is larger and the 2x4 frame is nailed into the earth with 2ft rebar every 3ft. The plastic is put on about the same. I don't have any problems with the wind but maybe your wind is worse...