A packet of seeds arrived in the mail yesterday, a kind kale. I’m slowly switching my garden over from summer’s tomatoes and chiles to fall and winter crops: Another round of radishes, turnips, carrots, and greens. Except rather than buying Russian Red or Lacinato or another kind of kale you stumble across just about everywhere these days, the seeds I bought are for sea kale.
Belonging to a different genus but the same family as more familiar kale varieties, sea kale or Brassicaceae, was a favorite of Thomas Jefferson and has one significant difference from its leafy cousins: It’s a perennial. A single plant will persist year after year, yielding tender asparagus-like shoots in the spring, then greens and peppery flowers throughout the summer and fall, before it goes dormant in the winter. Other annual kales have to be planted, well, annually.
Beyond being a sucker for weird vegetable seeds, my reasoning for planting sea kale is that a few plants will provide many, many more salads than an equivalent quantity of annual kale plants. Additionally, planting perennial food crops—which are few and far between outside of fruits and nuts and berries—helps to reduce topsoil erosion, can reduce the need for weed controls, and, in aggregate, can build a rich polyculture that, according to Wes Jackson of the Land Institute, could offer an alternative model for agriculture in the coming decades.
My sea kale experiment is by no means so utopian in scope, but a new column and video about Jackson’s efforts to breed perennial cereal grains done by Mark Bittman for the New York Times makes a compelling case for making a broader shift to perennials in agriculture. Jackson’s inspiration? The prairie ecosystem that, over the course of thousands of years, built up the deep, rich topsoil that made states like Kansas, where the Land Institute is located, into such prime farmland—topsoil that’s been slowly depleted thanks to the erosion caused by farming annual crops.