Around the turn of the last century, Beatrix Potter wrote a classic children’s book titled The Tale of Peter Rabbit. One of my earliest literary memories is of opening that book again and again to the page with the illustration showing Peter crouched behind a cucumber frame as he hides from Mr. McGregor in the garden. Although the picture shows only a corner of the cucumber frame (a glass-topped season-extension contraption that probably allowed Mr. McGregor to grow this warm-weather crop in a climate with relatively cool summers), one can easily recognize it.
When I was a little urchin, I never tired of opening to that page; it was the cucumber frame that enchanted me. I don’t remember what I thought about it, but I have clear mental images of being mesmerized by the partial view of this garden appliance. Perhaps it stimulated some long-buried past-life recollection; I can’t believe I had a clue how to use a cucumber frame. I know my father didn’t have a cold frame, and neither did any of the neighbors. (“Cold frame” is a generic term for any clear-topped contraption that modifies the garden microclimate — to facilitate growing cucumbers, for example.) And it wasn’t until I rediscovered Potter’s book when Jasmine and Laurel were little that I recovered the memory of sitting on my parents’ red couch, staring repeatedly at that picture. By the time I was a parent reading Peter Rabbit to my own kids, however, I’d developed a full-blown obsession with using my two cold frames to grow hardy crops of salad greens through the winter and to start vigorous seedlings in a protected environment in the spring.
The thing I find fascinating about a cold frame (and a partial view of one, at that) showing up in a children’s book is that it suggests how common these devices must have been in circa 1918 gardens. If that illustration were made today, Peter Rabbit might be hiding behind a lawn mower, a folding lawn chair, or even a discarded microwave oven. But I guarantee it wouldn’t be a cucumber frame, because they’re not part of the modern child’s common experience.
All the same, for modern adult home gardeners, the very possibility of using a cold frame to modify the garden climate holds a certain seductive allure, which grows as gardeners read articles on the subject. I’ll bet that fully 5 to 10 percent of all reasonably serious gardeners have an old window sash stashed somewhere in the belief that, at some unspecified future time, they’ll use that old window to make a cold frame. And the chances are pretty good that said window has languished for at least three years where it was dumped after being hauled home — probably with considerable effort. Even as you read this, countless potential cold-frame tops are rotting away as procrastinating gardeners periodically remind themselves, “One of these days, I’m going to put together that cold frame.”
And here’s the rub: If any of those well-intentioned gardeners ever did get it together to turn that window sash into a cold frame, they’d be making a really BIG mistake. Because sooner or later a child, a pet or a semi-inebriated adult is sure to sit or stand on a glass-topped cold frame — count on it. Unquestionably, glass has a long history of valuable service in the garden. But there are so many other excellent materials available to home gardeners today, and the danger to careless or ignorant loved ones is so great, it just makes sense to steer clear of glass.
If you really want to learn more about building and using traditional cold frames, go to the library and check out a book I wrote a couple of years ago: The12-Month Gardener. But please understand that you don’t have to build a cold frame — and you certainly don’t need to read my book — to be able to extend your gardening season this fall when frosts kill off those thin-skinned summer veggies. Whichever strategy you favor, though, now is the time to begin making preparations.
If you want to grow lettuce, broccoli, kale and spinach (to name only a few of the cool-hardy crops that thrive in our lovely fall climate), your single best investment is a fabric known generically as “floating row covers” or “garden blankets.” Local garden shops should stock this gauzy white material; if they don’t, you can find it in catalogs or via a Web search. Although it doesn’t give much of a temperature advantage, this wonder fabric does create a wickedly protected growing environment that lets your fall crops keep growing in spite of the weather. But whatever you do, get your “floater” together now, because the gods of autumn seem to take particular delight in zapping all your crops if you don’t have your garden blankets ready whenever the frost decides to arrive. (And conversely, if you have them, you won’t need them until way past the time when frost usually reaches your garden spot.) It’s an unexplained phenomenon (or a sick joke, depending on how you look at it) that’s well known to every longtime hardy gardener.
So start to get your seeds together over the next month, and make staggered plantings (a pinch of seed each week) from late July through mid-September. Every summer is different, of course, but with 20/20 hindsight, somewhere within that stretch will turn out to have been the perfect time for planting this year’s fall crops — and the weeks surrounding that prime time will yield dividends as well.
Beginning in early September, simply spread the season-extension fabric over the top of the emerging plants. And if you’ve never tried this before and you follow these instructions, you’ll be on your way to your longest gardening season ever.