Just got a great question from the earlier post. How much do I water in winter-early spring in my greenhouse? Not very much. Since I don’t have the drip systems on and I don’t want to empty hoses that might freeze, I fill up 5 gal buckets, leave them inside the GH and then fill up my watering can from them and water the plants. Five gal buckets are kinda heavy for me (40 lbs) so I prefer to transfer the water to a watering can. Or just fill up a watering can from your house and refill as needed. The only problem is my greenhouse is too far from my house to keep refilling a watering can from the house. Notice the white row cover on the side, ready to go back on the greens tonight when it gets cold.
This time of year is called the ‘shoulder season’—not quite winter and not quite spring-with extreme temperature swings from day to night. There is no set formula for watering because one day the temperature can be 60°F and the next day in the 40’s°F or even 30’s°F. Same with nighttime temperatures. Or you structure might really heat up in the day if you forget to open the doors or plastic on the ends or open the cold frame. So there are lots of variables that will affect how much to water. I really watch the plants and the soil in regards to watering when I have to do it by hand. Does the soil appear damp after your last watering even though its been maybe 4-5 days? Don’t water. Do the plants look like they need water? Are they looking stressed? Wilted? Water! The cooler it is, the less you have to water. I don’t water till the soil FEELS dry when I put my finger in it around a plant. But I can tell you this, you will be watering much less than in the heat of summer.