My porch / mud room / green house is like a life preserver to me during the dull, cold winter months. Covered with only single pane glass, it does cost me a bit to heat. But the oasis in the middle of the winter is worth it to keep some of my tender plants alive, and get a jump on spring with young starts you can't find at garden centers. Several years ago my wife gave me an electric heater by DeLonghi, equipped with a thermostat. I have it set at the lowest possible setting of 42 degrees, so the heat kicks on at that level. Just don't bump the heater. Knocks it off cycle. Don't have a power outage. Knocks it off cycle. Other than those two potential freeze ups, everything is fine. The porch usually stays 10 - 15 degrees warmer than ambient temperatures from the solar gain during the day. So I will bear the cost of heating the porch to keep stuff alive.
The two glass panels to the left are almost a direct southern exposure, with the ones to the right being western. In December, we were lucky to top out the day temps of just over 40 on cold days. A couple of days ago with it 30 outside but the sun bright, we hit 53 on the porch. Heat wave! I put the bamboo shades down at night, though that helps insulate just a tiny bit. Also at night, I turn the paddle fan on at low speed to distribute the heat, figuring the cost of the fan to be lower than the cost of wasted heat rising to the ceiling.
This shot is a flat with garlic starts in the front and 1/2 flat of arugula in the back. Darn, now I will have to lock the door to keep daughter Barb from snitchin the arugula. Grand son Wesley is known to eat his unfair share also. The garlic cloves were from some plants thrown away on the communal compost heap. They were too small to plant in the fall for a summer crop, so I figured I would try them inside. Maybe eat them as green garlic. Waste not. There are little tiny garlic starts in the back ground cell pak that were from the teeny tiny bulblets at the top of one of the garlic scapes. The literature says it will take 2 - 3 years for those plants to produce edible garlic. I can wait. Right now my time is cheaper than my money. Those little seeds cost me absolutely nothing, but will yield the joy of watching them develop. This particular arugula is "Ice Bred" from Fedco Seeds, though I just planted some more arugula from seed I saved from last year.
Till next time, dreaming of spring - George