I have read differing op's on using tires. One that there are chemicals that can leach into the soil. Though I did read about using them for potatoes in Mother Earth News back in the 70's.
Bos, have you tried heavy "cattle panel" hoops covered with poultry wire. I've no doubt it takes quite a bit to out smart a deer.
I had intended to use my chicken run double duty as a green house hanging planters to start seeds but it got so warm and humid I had to tear some plastic off the front. Controlling the temp in a greenhouse is not as easy as I thought too. It can get very hot in there.

Bos, have you tried heavy "cattle panel" hoops covered with poultry wire. I've no doubt it takes quite a bit to out smart a deer.
I had intended to use my chicken run double duty as a green house hanging planters to start seeds but it got so warm and humid I had to tear some plastic off the front. Controlling the temp in a greenhouse is not as easy as I thought too. It can get very hot in there.