If the first frost is your plant’s eviction notice, you might be tempted to obey it on blind faith. You look at a calendar date and yank things indoors, you drag them to the compost heap, telling yourself that what’s left outdoors must surely turn to mush or rot. It makes sense; this instinct are understandable. But it’s a big fall garden mistake.
Here’s why: Real life is less black-and-white than dead or alive. Lots of thing make it through the winter, sometimes better for being chilled. We tend to group all greens together by thinking that all greens need X. Nope. Lettuce isn’t like kale, for example.
Why Cold Is Good for Your Garden
Collards and kale tolerates colder weather. They can absorbs temperatures well below twenty degrees Fahrenheit. Why? Because when frost hits, the kale, et al., go through some sort of physiological change that causes the plant to take its stored starch and turn it into sugar, which serves as antifreeze. So what happens if you have Brussels sprouts? A good hard freeze makes them sweeter and less bitter. It doesn’t just preserve it; it improves it.
What about the semi-hardy things, lettuce and arugula? These guys can take a bit of a chill, but are toast with a hard freeze. Enter row covers. Lightweight fabric creates several degrees of warmth near whatever’s growing underneath. It’s not some high-tech magic, it’s insulation. Lettuce and arugula left uncovered will wilt. Covered: continuing production well into fall. That’s what one layer of fabric can mean: the difference between a large harvest than an abandoned patch.
A second option is root vegetables. If your ground isn’t frozen solid, you can continue growing carrots even through winter. This works best if your soil has plenty of organic matter and stay well-drained. You should of also use heavy mulching. Why? Because the soil itself insulates the roots and prevents them from freezing rock-hard. So you can pull what you need as required, or leave them in the ground longer, like having a natural root cellar.
Parsnips behaves similarly; so do carrots. Waterlogged soil will rot your roots before the cold does.
Work backward, of course, starting with your frost date, which you should know by now if you don’t. Don’t think about protection when the leaves go yellow; think about it as soon as you can get things planted so that hardy crops is growing well before the soil cools off. Let the kale develop good root growth before frost hits (and let other crops do their thing). Don’t try to winter a thin kale seedling. It is better to have a strong, established plant that handles cold weather well rather than one that never had time to grow.
Everything depends on fall timing. There’s no one-size-fits-all here: some crops are finicky (peas for example, which can take a bit of light frost but not extreme cold). Others, such as broccoli, appreciates a bit of cold but will be happy protected if the temperature drops too low for too long.
Observation is the trick. What happens when you have a night or two of cool early weather? Do the plants’ leaves curl up, or go crispy? Pay attention (your garden speaks). Working with nature instead of against her is the key to extending your gardening season. Knowing who likes the cold and who doesn’t will allow you to enjoy homegrown vegetables well past the point when your friends put up their shovels.
Sure the ground may be covered in snow, but that doesn’t have to mean no more garden for you. Actualy, many times the vegetables require the cold. Next time you notice your kale leaves getting frosty, don’t fret. You’re just that much closer to a sweeter dinner.