A lot of greenhouse gardening concerns revolve around temperature. This is true whether you are gardening in the middle of summer or in the throes of winter. For winter and early spring gardening, however, the first thing you need to decide is whether or not you will be heating your greenhouse. I opted to keep my Palram greenhouse unheated. There are electric heat options as well as propane and paraffin heat solutions available that you can consider. As you surely know, heat has a price tag attached, so this may pack a wallop on your wallet, especially if you live in an area with a long winter season. You will need to consider if the output of your garden greenhouse will be worth the expense of heating it, so you may want to open an Excel spreadsheet and crunch some numbers. For many, however, the heat required to grow warm season crops such as fresh tomatoes, peppers and beans is simply priceless.