Patio heaters are very bad for our environment. They are an extremely damaging way of producing heat and consuming it. A standard 13 kg canister of natural gas will warm an area outside of up to 25m2 for 12 hours while the same canister used in a gas fire could heat the same area indoors for 10 times longer!
We must also be aware that patio heaters emit, for every unit of heat, far more noxious fumes than most cars!
Remember to recycle: plastic bottles cut in half make nice cloches for seedlings. Plastic food trays, cups, jugs and bowls are great for growing seedlings.