Rocket (Eruca sativa Mill.)
If somebody, some 25 years ago, had said that we in the Nordic countries would become large consumers of rocket, it probably would have raised deep suspicion and distrust. “Rocket?” you wonder. It sounds a bit more like a super-sweet breakfast cereal, does it not? Well, that is actually the name in English of what most people today known by its Italian name rucola.
Text: Jens Weibull
Today’s vegetable dishes and salads comprise a rich selection of different leafy vegetables and not just iceberg or lettuce: mizuno, mâche, baby spinage, lollo rosso, frisé, romano – well, you name it. Mâche, or common cornsalad, has already been portrayed in the series of important crop wild relatives. Today, we highlight rucola, or rocket. The species has been used in the Mediterranean diets since time immemorial, where it also originates. Its leaves are tastefully peppery. Rocket is also cultivated further afield in the Middle East and South Asia where the small seeds are pressed to produce a spicy oil. The annual plant is member of the Brassicaceae – the crucifers – where also rapeseed, carrot and radish belong. Flowers are large and bright yellow with nice red-purple streaks, and the siliquas – or pods – that hold the seeds are elongated and round with a pointed “nose”. In the Nordic flora rocket is an occasional, or adventitious, guest.
Rocket is a tolerant species that can be grown almost anywhere. It is tempting to believe that the English name rocket (French roquette) comes from the fact that the species often grows among stones and rocks, but of course, that is simply too good to be true. The Latin word eruca means in fact rocket. In the Southern parts of Norden, it can keep growing until well into autumn or even later during mild winters. That way you can harvest fresh leaves for a long time. Remember, though, to cover it up with a thin fabric when the plantlets establish. Rocket is extremely popular among cabbage flea beetles (Phyllotreta spp.) that can easily cause great damage within no time! A species that is often called wild rucola, and commonly available in seed stores, is perennial wall-rocket (Diplotaxis tenuifolia (L.) DC.). As told by its name it is, unlike the rocket, perennial and has a slightly more pungent flavour. Diplotaxis grows wild on sandy soils in ruderal areas throughout the entire Nordic region. Harbours and railway yards are environments where the species thrives.
Rocket can be used in so many ways other than a plain salad. Why not also try it in pies, a Chinese wok or lightly braised as a slightly spicier alternative to spinach? Pliny the Elder (23-79 A.D.) praises Eruca in his The Natural History (Naturalis Historia), not only for its cold tolerance but also for its properties to provoke lust. Could that perhaps be one of the reasons for its popularity? “Rocket, more particularly, is able to stand the cold, and its properties are quite different from those of the lettuce, as it is a great provocative of lust. Hence it is that we are in the habit of mixing these two plants in our dishes, the excess of cold in the one being compensated by the equal degree of heat in the other.” (Book IXX, Chapter 44 – OTHER PLANTS THAT ARE SOWN IN THE GARDEN: OCIMUM; ROCKET; AND NASTURTIUM)
