Cooking with greens in the hottest months of the year takes some rethinking. If you have your palate trained on winter’s kale, collards, turnips and other cool-season leafy brassicas, summer’s holdouts can be disillusioning. Though such cold-hardy greens will produce leaves in the heat if given enough shade and water, they aren’t keen on it. You can taste their resistance in bitter, less-tender leaves that are no longer the center of the plant’s attention.
Longer, warmer days trigger plants to launch into bolting: the process of sending out flowers and producing seeds. This switch in gears, explains Gerald Brust, vegetable specialist for the University of Maryland Extension, diverts enzymes and nutrients — flavor — away from the leaves and into the immediate, more important task of reproduction.
You could temper your expectations, making do with cool-season greens throughout the year. But it seems more sensible to work with the greens that don’t just tolerate mid-summer heat but thrive in it. Purslane, callaloo, Malabar spinach, lamb’s quarters, the greens of sweet potato plants: These are less familiar yet no less worthy of the table.
Summer’s greens taste, maybe expectedly, like products of the season. They are more easy-going in flavor, with less of the earth, pepper and bite that so often accompany cold-season greens. (Dandelion is an exception.) Instead, they suggest butter, lemon, brine. A heap of New Zealand spinach I sauteed recently with garlic, chili pepper and olive oil suggested oyster liquor, in the best way, and I nearly went right back to the stove with the rest of the bag.
That type of hot-weather spinach, as well as Egyptian spinach and Malabar spinach, are so called because they bear a resemblance in flavor and texture to the Spinacia family. In fact, they belong to a class of plants called succulents, along with callaloo, sweet potato greens and purslane. The trick they call on for moisture management ensures their leaves stay tender even in hot, dry conditions inhospitable to most other leafy greens.
“Succulents tend to store a lot of water in their stems,” Brust explains. “When it’s dry, they’ll use the reserves.”
They taste the part. Purslane is tender and lush enough to redefine expectations of what a salad should be. You can cook purslane as well; cookbook author Deborah Madison writes, in “Local Flavors” (Broadway, 2002), of Hispanic growers in her adopted town of Santa Fe who suggest sauteing it with onion or adding it to a pot of beans, and the traditional Mexican pork and purslane stew (called, simply, pork stew with purslane), makes use of it aplenty.