I’ve always been tickled by the pairing of decadence and duty at the Swanton Berry Farm stand at the Berkeley farmers market: sweet, fragrant, addictive strawberries sharing the table with fibrous, disrespected, and most-likely-not-addictive broccoli, cauliflower, and brussels sprouts. It turns out that this collection makes a lot of agricultural sense, as strawberries are the natural partner of Brassicas like broccoli, cauliflower, and brussels sprouts.
Chapter two of Samuel Fromartz’s “Organic, Inc.” explains the partnership in detail. Fromartz visits with Jim Cochran, founder of Swanton Berry Farm in Davenport, California, to see how strawberries are grown organically. Through careful observation and experimentation, Cochran discovered that members of the Brassica family (brussels sprouts, broccoli, and cauliflower are a few members) protect against the fungal disease virticillium wilt, which is a potent destroyer of strawberries. The fungus can remain viable in soil for years, just waiting for a target like a new batch of strawberry seedlings. Methyl bromide — a neurotoxin and ozone depleter — is effective at killing the fungus and therefore is used in most non-organic strawberry farms in the U.S. (its use is banned by the Montreal Protocol treaty but U.S. growers have received special exemptions to use it).
A few years later, a plant pathologist at UC Davis, Krishna Subbarao, identified what was happening. An outbreak of virticillium wilt was ravaging cauliflower fields, but adjecent fields of broccoli were unaffected. After several years of research, he discovered that broccoli carries a natural fungicide called glucosinolate. Apparently the compound feeds helpful soil bacteria which then eat the virticillium fungus. At the time of the publication of “Organic, Inc.,” the bacterium had not been identified, and for a good reason: a gram of soil might be home to 10,000 different species of bacteria, many of which are unidentified.
Thus, rotational planting of broccoli and other Brassicas with strawberries has been one of the keys to organic production of strawberries. Other techniques that Fromartz recounts include the use of predatory mites (Phytoseiulus persimilus) to reduce the population of a pest mite, planting flowers and grasses nearby to attract pest-eating insects or to draw pest insects away from the crops (the lygus bug, a strawberry-eating pest, apparently prefers mustard over strawberry) and maintaining good soil fertility by using cover crops between strawberry plantings. (The history of the commercial strawberry is also a very interesting one, involving several species of strawberry, transatlantic plant transfers and a chance meeting in Paris, as I summarized in a 2005 post at Mental Masala.)
Although cauliflower is not so effective against the virticillium wilt, I much prefer it to broccoli, so here’s a tasty recipe for cauliflower. I hope it will make you appreciate cauliflower in a whole new way. The key is to roast the vegetable in a very hot oven to brown the edges, unleashing the power of the Maillard reactions.
Cauliflower comes in many varieties: the purple (shown at the top of the post), the classic creamy-white, pale green, and the self-similar Romanesco are just a few. They are similar enough that one can generally substitute for another in any recipe calling for cauliflower. Keep in mind, however, that the color will change during cooking; the purple variety typically turns brown or green.
Roasted Cauliflower Salad
Slice the cauliflower into bite-size pieces (about the size of an unshelled walnut). It is important to slice the vegetable instead of breaking off the florets so as to provide flat surfaces that will brown during the roasting. Toss with oil, sprinkle with salt, then arrange on a baking sheet. Roast in a 400 F (or hotter) oven until the cauliflower is tender and brown in places, turning once or twice so that each side touches the hot metal pan for some time, about 20 minutes or so. Set aside to cool while you make the dressing. You could steam the cauliflower in a pinch, but roasting brings out a sweetness and complexity.
Roughly chop a clove of garlic (or more) and place in a mortar along with some salt. Use the pestle to fully crush the garlic into a paste. Pour in some lemon juice, a bit of Dijon mustard, and stir to combine. Wisk in olive oil (about a 1-to-1 ratio).
Combine the dressing, the cauliflower, some capers, fresh cracked black pepper, and herbs (like parsley).
Serve warm, at room temperature, or chilled.
Inspired by a post on A Few Reservations