Rocket

Origin & history

Salad rocket comes from the Mediterranean and Western Asia and was already an everyday kitchen herb to the Romans under the name eruca. In German gardens it was then all but forgotten and only returned with the Italian food wave of the 1980s. Botanically rocket is not a salad at all but a brassica, related to mustard, cress and cabbage — its heat comes from the same mustard oil glycosides.

Varieties

Two different plants sit on the shelf under the same name: annual salad rocket (Eruca sativa), with broad lobed leaves, is ready in four to six weeks but bolts quickly. Wild rocket (Diplotaxis tenuifolia) has fine, narrowly cut leaves, tastes markedly sharper, is perennial and re-shoots in the bed for several years. For quick supplies between other crops take salad rocket; for a permanent cutting patch take wild rocket. Both are open-pollinated and, once allowed to flower, self-seed readily.

Care

Thin to about 5 cm and then run it as a cutting patch: cut the whole row three to four centimetres above the ground and it will come again two or three times. Keep it evenly moist — drought stress makes the leaves tough and fiercely hot and pushes the plant into flower. Do not feed it; on a freshly manured bed rocket just grows big and bland. Cut wild rocket back by a hand’s width after flowering and a fresh set of leaves follows.

What can go wrong

Flea beetles are the main problem: tiny black beetles that turn the leaves into sieves in warm, dry weather. Fine-mesh crop netting from the day of sowing keeps them out reliably, and soil kept moist and hoed regularly helps too — late-summer sowings stay far cleaner than spring ones. As a brassica, rocket also belongs in the cabbage rotation: leave at least three years between it and cabbage, radish or mustard, or it helps clubroot build up.

Harvest, storage & kitchen

Pick young, when the leaves are about a hand long — older and flowering plants turn stringy and very hot. Rocket barely keeps: loosely bagged, into the fridge and used up within two days. Add it to warm dishes only after they come off the heat or it collapses; the yellowish-white flowers are edible and look good in a salad.

Frequently asked questions

Are rocket flowers edible?

Yes, both the flowers and the buds. They taste milder than the leaves of a plant already in flower — salad rocket flowers whitish, wild rocket yellow. Pinching the flowers out will not stop the plant, though: if you want tender leaves again, sow a fresh row.

When can I sow rocket?

In two windows: from mid-March to the end of May, and again from early August to early September. Picking runs from late April to mid-July and, in autumn, from early September to mid-November. Sow about 1 cm deep.

Where is the best spot for rocket?

Part shade is ideal, especially in summer: the leaves stay tender there and the plant bolts later. In spring and autumn a sunnier place is fine — what matters then is soil that does not keep drying out.

Is rocket winter hardy?

Not really. It shrugs off light frost and so stands in the bed into mid-November, but a hard winter outdoors finishes it. Perennial wild rocket often pushes through again in spring in milder areas.