Tucking your cold-weather babies into beds

Frankly, they look a little like Halloween decorations: billowy, semi-sheer white fabric pieces draped over two of my urban front-yard garden's raised beds. Ghostly, or perhaps spider-webby.

What I'm hoping they'll do is anything but scary. These floating row covers can protect plants from wind and dropping temperatures as we stream through fall and into winter, and I'm counting on them to extend my garden.

Row covers aren't the only way to do this - greenhouses and covered hoops are two of the others - but the fabric is surely the simplest and cheapest, the equivalent of a lightweight scarf around the neck. I spent just a few dollars on many yards of a medium-weight fabric that lets in 85 percent of the sunlight plants need to grow, while giving those plants up to 4 degrees of frost protection. Four degrees might not sound like much, but it could translate into many weeks when the plants are warm enough to keep growing, or at least to survive.

For even more frost protection, I could be using a heavier fabric, but the trade-off is that it lets in less light, so the plants won't grow as quickly. It's not time for that, not yet.

I put my covers down last month, one of them on a bed where I had seeded carrots, radishes, beets, kale and spinach a few weeks earlier, and another on a bed where I had just sown some spinach and arugula seeds. The kale probably won't get big enough to feed me much of anything this fall, but I'm expecting some baby spinach and arugula - and maybe some carrots and radishes - to make it to my Thanksgiving table.

Come spring, if we don't have another harsh, killing winter, the fabric should be able do even more magic.

"With spinach, arugula, certain lettuce varieties and even kale, if the plants go into the fall, and they're immature but healthy, and there's a row cover over them, in March, when the regrowth starts, they start growing like crazy," says Jon Traunfeld, extension specialist and master gardener program coordinator at the University of Maryland. "The growth can be incredible. They'll be way ahead."

Some caveats: Even though the row covers increase the temperature of the air surrounding the plants and help them maintain more moisture (even as the winter air gets drier and drier), they won't make a difference in one of the most important factors of vegetable gardening: soil temperature. So gardeners who think they can get a late start on sowing seeds in the fall, only to make up for it with a row cover, will be disappointed. And if you use them over plants that require pollination, such as squash, you'll need to uncover them and let the pollinators in at some point if you hope to have any fruit.

The fabric - usually spun-bonded polyester, UV-treated to withstand the sun - also can help protect against pests, which is the main reason some gardeners use them. I haven't had much of a pest problem yet, but that could change as quickly as, well, the weather.

Some gardeners bury the edges of the fabric in soil to keep them in place, but I used some extra bricks I found underneath my porch. It's best to avoid staking the fabric, as I learned by mistake, because one tear could be exacerbated as soon as the wind starts whipping things around. I also used a generous amount of fabric and left a lot of slack so the plants would have room as they grow.

Some plants, such as eggplant, can suffer leaf damage from direct contact with row cover fabric, Traunfeld says. In the winter, if the cover is wet and then freezes, that could damage leaves, too. That's one of the reasons some gardeners prop up the fabric with wire hoops, sticks or even filled water bottles.

I don't have the time for that right now, so I'm content to leave the Halloween look intact and the fabric loosely draped, peeking underneath periodically to make sure the plants are comfortable and making adjustments if I think frost damage is imminent. When the weather gets colder, if it seems like they would appreciate a little more protection, I'll consider switching to a heavier fabric - or maybe just doubling up on this one. Sometimes all you need is a warmer scarf, or another layer, to feel just fine.