I was very fortunate to inherit a 12’x 10’greenhouse and an 18’x 10’polytunnel when we moved, I am relatively new to veg growing but have been using the greenhouse for sowing and bringing things on before planting in the polytunnel, it seems to work. I have some tomato plants growing in the greenhouse also aubergines and peppers, all in pots, they seem to cope with the heat, the greenhouse is in a sunnier position and can get very hot inside. I also use the greenhouse to overwinter some tender succulents, as it is easier to keep frost proof. I have been planting directly into the polytunnel borders, and since reading Charles’ excellent book, I have been piling on the manure. I hope you find this helpful.