How can you trick your plants into thinking the outside world is warmer than it is so they’ll keep producing food well into the winter months? If you live in the northern hemisphere, chances are you’ve started to see the first hints of the cold season poking up around you. Here in Quebec (where this writer is reporting from), trees are donning their autumn finery and the lush greens of the forest are turning to all shades of red and gold. Farmers nearby are busy harvesting the abundant vegetables and fruits that their fields are teeming with, and we’ve all been canning like mad fiends to preserve this gorgeous harvest for the winter months. At this time of year, many people are already clearing out their gardens and composting the remnants of herbs and other plants that have already gone to seed and wilted, but there are still many plants that can be left in the ground to continue producing food for another few months. If you trick them into believing that it’s warmer outside than it actually is, you might be surprised at how long they’ll continue to grow.
Hardy vegetables like kale, cabbage, chard, lettuce, broccoli, Brussels sprouts, turnips, parsnips, and beets will over-winter well, and you’d likely also have a fair bit of luck with herbs such as rosemary, parsley, and members of the mint family. They’ll last a surprisingly long time if you create a greenhouse-like effect for them with covers made of glass or plastic, be those pretty bells you find at flea markets, or those you make yourself from inexpensive scrap materials. Really, the key is to be sneaky and trick your plants into thinking that winter hasn’t set in yet by keeping the snow and wind away from them.
These bell-shaped glass covers (also known as bell jars) are absolutely brilliant; they’re beautiful as well as utilitarian, and ideal for protecting individual plants from winter’s chill. They can run on the expensive side, but you can often find them at a much lower price at flea markets, vintage shops, and on Ebay. If you want a really inexpensive garden cloche, aim for plastic instead and just cut the bottom off a 5-gallon water bottle (the kind you buy at the grocery store to use in a water cooler, or with a hand pump).
Note: be sure to only use glass cloches in areas where they’re not at risk of being crushed by large falling icicles or heavy lawn furniture—the last thing you want is a bunch of broken glass floating around in your soil.
Most people use cold frames to protect new seedlings from frost and inclement weather in early spring, but they also have a splendid secondary use—helping us lie to our plants so they don’t die off at the first sign of snowfall.
Another great thing about cold frames is that you can build them from random scraps you may have in storage. I’ll be building a new set with a variety of old, discarded windows that I’ve found in the forest paired with bits of lumber my father-in-law has had in his garage for years. Old glass doors, lengths of plexiglass, discarded wooden skids, and hinges from old doors and cupboards can all be given new life and purpose by using them to make these marvelous mini greenhouses, keeping them out of the trash and helping your garden thrive.
Note: a great place to find discarded windows, doors/hinges, and lumber for free is in the dumping ground behind film sets and TV studio locations. Sets for commercials and movies are torn down shortly after they’ve been filmed, and all of the lumber and glass that was used usually just ends up in a landfill. You can score an absolute treasure trove by swinging by those places regularly and doing a little dumpster diving.
Don’t they sound cute? Say “hoophouses” a few times and try to stop yourself from smiling. These are occasionally also referred to as poly tunnels, but the latter generally implies a large tube that farmers use for their spring seedlings, and we’re just talking about the wee ones for home gardening purposes. Made of polyethylene sheeting and PVC pipe on a wooden frame, these are great for covering larger growing areas. The easiest and cheapest way for you to make small hoophouses to use in your own garden would be to hack apart a couple of old hula hoops, bend them into C shapes, screw the ends into a simple wooden frame made of scrap lumber, and cover the lot with polyethelyne sheeting. If you think the sheeting needs extra support, you could always lay down a skeleton of chicken wire beforehand. Don’t make the hoophouse too large — you’ll want it small and lightweight enough that you can pick it up and move it by yourself when tending to the plants beneath.
If you plan to use any of these methods to cover your plants for the winter, be sure to also give their roots a little extra TLC by adding some protective mulch to the soil around them for added warmth. Good luck!
Lead image by Maggie McCain via Flickr Creative Commons