My artist friend Sherry keeps a handsome garden, her vegetables and herbs mixed with bright marigolds and neatly composed within wooden frames. The day I stopped to admire them, her beds were weedless except for scattered purslane seedlings, a pest of high summer that appears when the hot weather has settled in. Purslane had just spangled my own garden, too.
“It’s easier to remove when it’s big,” I remarked. The plants, as they grow, form the spreading mats that give them the Spanish name verdolaga or “green lake.” Grasp each mat’s center, where the taproot has formed, then pull; in minutes you have a bucket full of purslane. You can also hoe them when they are large, skimming just under the soil surface so the root system stays in the ground. But hoeing the tiny ones tends to just move them around, ready to regrow as soon as it rains.
“What if I just left them there?” Sherry wondered aloud. It was an idea both brilliant and blasphemous, and I thought about it over the next few days. Garden dogma treats all weeds as invaders that compete with your crops for space, nutrients and moisture. But there are other ways to look at them.
My husband, Eliot, has at times used red clover as a living mulch, undersowing a crop such as fall broccoli with it to prevent a muddy harvest. The clover stays put in winter, protecting the soil against erosion, and is tilled under in spring. As a legume, it adds an extra measure of available nitrogen to the soil. “Soil is much happier with vegetation on it,” Eliot says.
This brings to mind the philosophy of another friend, Bob Cannard, who raises vegetables on two farms near Sonoma, Calif. Cannard is famous for his tolerance of weeds, but his approach requires very careful management, as you can learn from a terrific 10-minute video posted on YouTube. It’s a matter of paying close attention and calculating the amount of time and space a weed may share with a crop. Lettuce, planted early, will be cleaner at harvest time if weeds have been given special dispensation around it. These will then be mowed and dug under when three-quarters mature, just old enough to replace the nutrients they’ve taken from the soil. The diversity that a mix of weeds brings to the garden also encourages a diversity of insect life — and a better balance.
I wouldn’t play these games with a super-competitor like galinsoga. But a green lake of purslane, pulled before it went to seed, might not be the worst thing that ever happened to a garden bed. As a succulent, would its fat, fluid-filled leaves compete for moisture? Maybe. But I’ve noticed that when weeds shade the soil, evaporation is curtailed and more moisture is retained. That’s another reason why larger ones are easier to pull.
Besides, purslane is not only tasty to eat but also highly nutritious. It’s both foraged and planted on purpose in countries such as Greece and Mexico, where it’s part of traditional cuisine. Raw in salads, it has a lively flavor and a pleasant crunch. Try it sauteed with onions and hot peppers, or dropped into a soup to thicken it. Not many garden greens love to grow in hot summer weather, and that alone earns purslane a pardon.
Tip of the week:
If you are planning a total renovation of a weedy lawn in late summer (as opposed to overseeding an existing lawn), you should kill the vegetation with an herbicide first. Do this soon so that the effects of the weedkiller have dissipated by the time you spread grass seed. You might need to make two or three applications of a non-selective herbicide such as glyphosate to kill all the vegetation. Wait at least a week after the last application before sowing the fresh lawn. The waiting period for other herbicides might be longer. Follow label instructions.— Adrian Higgins
Damrosch’s latest book is “The Four Season Farm Gardener’s Cookbook.”