We’ve all seen greenhouses pressed into service for winter gardening, and some of us have used them ourselves; and of course, there’s always the handy coldframe or hotbed to help plants along when it’s icy. But one option you may not have thought of is a hoop house, a kind of mini-greenhouse that you can erect over a single row or bed. It’s a commercial agricultural idea that can easily be applied to home gardens, like the one they’ve got going at the garden at the White House these days.
Also called a “low tunnel,” a hoop house is a very simple structure. All it requires is a series of metal, plastic, or wooden hoops that fit over a row or bed, covered snugly with plastic or tightly woven fabric. The material traps heat from the sun, and keeps plants from freezing during colder weather. It’s an ideal solution if you’ve got multi-year crops like asparagus or rhubarb that you’d like to survive the winter, and it’s great protection for standard winter garden veggies like chard, lettuce, and mustard greens, too.
The only real drawback is that you can’t water your plants from overhead, unless you build a very large hoop house—and if you do that, it might as well be a full-fledged greenhouse. There’s no problem with standard row irrigation, however; and in any case, plants need much less water during cool weather. Some don’t see this as a drawback since watering from overhead can lead to soil borne diseases splashing on leaves of the plant.
Easy to build hoop houses are relatively inexpensive—perfect for the garden tinkerer. And they’re good for more than just warming cool-weather crops. Replace the fabric with a small-weave mesh in the spring, and your seedlings will be protected against those birds, like crows and ravens, that are crafty enough to know that there’s a tasty seed underneath that new plant. The birds won’t be able to reach the seedlings, but the seedlings will get all the sun and water that they need.