There’s nothing subtle about arugula. Dark green and intensely flavoured, the lobed leaves may well be an acquired taste—and whether or not you enjoy them could depend on your first bite. Small young leaves give a peppery edge when mixed with lettuce under an oil and balsamic dressing, but older, overgrown arugula has a tang and bitterness that’s harder to appreciate. Arugula (Eruca vesicaria ssp. sativa), or rocket as it’s sometimes known, is closely related to watercress, mustard greens and radishes; and like other leafy members of the Brassica family, goes from tender and gently pungent to tough and hot as it ages.
The secret is to grow a small patch, pick the leaves at their tender best and root out the plants when they become unpalatable; then to have a second and third patch coming along in succession. Fortunately, arugula is a simple green to cultivate from seed, sprouting quickly and growing vigorously like the half-wild thing it is.
When to plant
A true cool weather plant, arugula does well at both ends of the growing season, May through June and then again from September to November across most of Canada. Cool weather and abundant moisture impart a mild, nutty flavour, distinct but good, while midsummer heat and drought make for leaves so strong-tasting that you might just spit them out.
Given their ability to germinate at soil temperatures as low as 10°C, arugula seeds should be one of the first in the ground, about the same time as spinach seeds and onion sets—around mid-April in our Zone 5 garden, or a full month-and-a-half before frosts are over. But frost is no threat to small arugula plants, and an April seeding brings leaves to the table by the May long weekend, traditionally the time to be “putting in the garden,” not picking.