The true harbingers of spring—ramps, fiddleheads, and asparagus—are still a few weeks off, so the spinach, salad greens, and broccoli rabe perking up farm stands are here by the grace of thoughtful farmers, whose overwintering techniques provide fresh greens before they’re typically in season.

Overwintered crops are planted in the fall, and are sometimes covered with hay or other insulating materials or protective structures. They lie dormant during the winter and spring to life when the days start getting longer and the ground gets warmer, typically in early spring. "They tend to be delicious and sweet," says chef Spike Gjerde of Woodberry Kitchen in Baltimore, a restaurant that hews closely to local producers and seasonality. "They're around when we most need something that's green on our menu," he says referring to the moment when the restaurant's preserved vegetables are running low.

Overwintered vegetables tend to taste sweeter than their seasonal counterparts because, as a defense, plants produce more sugar to keep themselves from freezing to death. The result is more residual sugar on the palate. A lot of vegetables, including cauliflower, Brussels sprouts, carrots, and kohlrabi, can be overwintered, but greens are especially common.

If you see hardy greens at a farmers market right now (between February and April), they’re probably overwintered. Take a cue from chef Gjerde and ask your farmers about their practices. “I never get enough of listening to and learning from them,” he says. If they have overwintered greens, it’s likely other produce in their stalls is overwintered, too.

Treat overwintered greens exactly as you would regular-season greens. This tangy, spicy braise from Gjerde is a simple and delicious way to put them to use.