Winter gardening: cold frames and greenhouses
Here are your choices for growing things in the cold weather.
This is perhaps the priciest of the choices, but the further north you live, the more it makes sense. From Wikipedia:
A greenhouse (also called a glasshouse) is a building in which plants are grown. These structures range in size from small sheds to industrial-sized buildings...
Ventilation is one of the most important components in a successful greenhouse. If there is no proper ventilation, greenhouses and their plants can become prone to problems. The main purposes of ventilation are to regulate the temperature to the optimal level, and to ensure movement of air and thus prevent build-up of plant pathogens (such as Botrytis cinerea) that prefer still air conditions. Ventilation also ensures a supply of fresh air for photosynthesis and plant respiration, and may enable important pollinators to access the greenhouse crop. Ventilation can be achieved via use of vents.
Here are some sample greenhouse projects and suppliers.
- Look! Greenhouse made from salaved materials
- Lancaster backyard greenhouse kit (This one looks pretty easy to build without the kit.)
Here's a design similar to what I used last winter. May I warn you from experience that you do NOT want your plants touching the plastic?
And here's a good book on the subject: Backyard Greenhouse Plans, by Bill Keane
A miniature greenhouse is known as a cold frame. East to make, inexpensive, and big on results, a cold frame may keep you in fresh produce all winter. Cold frames are typically set on the south side of the yard, in full sun, and it's a good idea to have them up against the wall of your heated home, even though they mostly use solar heat. Make the back about 12 inches higher than the front. During sunny days the sash can be propped open with a stick to prevent sunburning the plants. If the sun is bright, temperatures in a cold frame can reach 85 degrees Fahrenheit even when the temperature outside is freezing. Close the frame at night and during cold weather to protect young plants.
A traditional (cold frame) plan makes use of old glass windows: a wooden frame is built, about one to two feet tall, and the window placed on top. The roof is often sloped towards the winter sun to capture more light, and to improve runoff of water, and hinged for easy access. Clear plastic, rigid or sheeting, can be used in place of glass. An electric heating cable, available for this purpose, can be placed in the soil to provide additional heat.
Here are some sample cold frame projects and suppliers.
- This one is made from cinder bocks and old glass doors
- Simple polysheeting and 2" x4" cold frame (This one looks pretty easy to build.)
- How to build a cold frame for your garden (from Vegetable Gardening for Dummies)
- Good, fast crops to grow there: Quick-maturing vegetable varieties
Not everything needs to grow outside. From fresh herbs on a windowsill to an indoor Meyer lemon tree, when it comes to houseplants, this bud's for your table. Choose compact, miniature, or dwarf varieties of crops and crops that are quick maturing. Small, quick-growing crops will require less space and time to reach harvest. Grow lights are an option, but have a large energy cost. Hydroponics can be done small-scale indoors, too!
- You Grow Girl blog, tag windowsill gardening.
- Dwarf and miniature vegetables for containers
- http://anr.ext.wvu.edu/lawn_garden/gardening-101/vegetable-gardening/indoor-vegetable-gardening (great chart!)
- http://www.hydroponics-simplified.com/indoor-vegetable-garden.html, with a link to a book on the subject.
Finally, don't forget that an indoor sunroom can act as a greenhouse. Yes, I know - we're talking about an extension on your home. Not cheap. But if you're in a position to add a sunroom to your permanent northern home, it can provide passive solar heating plus a great place to grow that Meyer lemon or other fruit trees.