I've been looking at the hoophouse plans that are on the message board, and I am getting ready to build one, but before I do, I just had some questions...... #1. Is it really worthwhile in IN? Can the basic build-it-yourself out of pvc pipe really keep the plants warm enough??? It is -1 degree F today where I am at.... #2. How often does the plastic need changed? #3. I swear we have 400 mile an hour winds here...OK, a little sarcasm, but it is VERY windy at times...Can the 4 mil plastic hold in very windy conditions??? Thanks SO much for all of your help and for posting your plans on hoophouses....they look easy to build, cheap to build, I just want to know if they are worthwhile for where I live.... Thanks again!!!!!!!!!