Spring in Kansas can create a challenge for getting an early start on plants. Once the weather begins to warm up, the urge to start planting just can’t be denied. But unfortunately, just because there is a couple of weeks of warm weather, does not mean winter is over. The temperatures always drop below freezing at least one or two more times. Even in the green house, that is too cold for tender seedlings to survive.
So I set out on a mission to learn how to heat the greenhouse. I didn’t want to keep it hot, just above freezing. My goal was to keep it at at least 40 degrees over night, even when the lows dropped into the 20s.
I researched a number of heaters and finally settled on a heater that ran off of propane that seemed like it would heat the area. While it provided quite a bit of heat, it ran off of small propane tanks or grill-sized tanks. Those only lasted about two nights, so that was very economical or feasible.
After a visit to a friend’s greenhouse, I learned he used a blue flame heater, which was hooked up to a larger propane tank. With that, I knew I had to think bigger than just a portable heater. I decided to have a propane tank installed and a line run to the greenhouse. I have a small, wall-mounted blue flame heater that works well to keep the greenhouse warm when the temperatures are in the 30s. It usually stayed about 10 degrees warmer than it was outside.
When it recently dropped into the 20s, I did supplement it with a couple of electric space heaters, which kept it in the 40s. Another thing that helps is to put a fan in front of the heater to help circulate the warm air. Now my seedlings have a warm place to continue growing until they can go out into the garden.