We installed my greenhouse a year ago, and I made mention of it here. Being that it is so close to spring this time of year, I really didn't have the benefit of winter weather to get to know it last year. So, this year, I've had a sharp learning curve. What I didn't realize was how drafty it is and how hard it would be to keep warm during the winter. It heats up nicely during sunny days, but at night when the temperatures plummet, the greenhouse temperature follows closely behind. So closely, in fact, that when temperatures hit lows in the teens recently, the seedlings in my greenhouse froze. Oops! Now I'm behind the eight ball with my seedlings this year, so lesson learned. So for the past month, I've done some things to monitor and control the temperature a little better and to tweak some things to make it work better for me.
1. I bought an indoor/outdoor thermometer. I put the outdoor sensor in the greenhouse and the base inside. Now I can monitor the temperature from my office to get a better idea of the temperature ranges throughout the year.
2. After much nagging, pleading, threatening, blackmailing, begging and basically having a meltdown, I finally got Nate to run electricity to the greenhouse, which means I can use germination mats and eventually grow lights when I can afford them. I think the germination mat has helped tremendously, not only to keep the seed trays above freezing some nights, but to help the warm weather seeds, such as eggplants and peppers, get a jump start.
3. When we installed the greenhouse, we knew we would have to add shelving. At the time we finished, we were so sick of the project that I don't think I could have gotten Nate to build shelving for a million dollars. So, I spent more money than I wanted to on pre-made shelving. What I love about the shelving is that the shelf heights are easily adjusted and I can add or take away shelves as I need them. I would not have had this feature if Nate had built them for me, so I'm happy about that. And, since they are 4' in length and 2' wide, they hold a large germination mat and 4 seed trays perfectly. However, the shelving came stock with particleboard shelves and eventually the particleboard buckles in the center from the moisture, so I knew I would have to replace them eventually. My solution is to use decking boards. Because the boards are not a true 6" in width, they don't take up the entire width of the 2' space. Our solution is to put two screws on each board to hold it securely against the next one. Now the shelves are secure and won't buckle from the moisture. I'm slowly working on replacing the particleboard as each one buckles and as the budget allows.
4. Another thing I've tried to do is to create thermal mass. I added mulch on the floor, and as it decomposes, it will create heat. I would also like to add some type of water container, be it just a barrel of water or even some type of hydroponic or aquaponic system. Once again, the water will heat during the day and release that heat at night, thus helping heat the greenhouse a smidge better.
Maybe at some point, I'll research some type of solar heater, but for now, I'm happy just to get some baseline items out of the way.