How to Grow Awesome Arugula (or Remarkable Rocket!) For Longer

19 October 2023, written by Barbara Pleasant

Whether you call it arugula or rocket, Eruca vesicaria or its close cousins deserve a place in your garden. Delicious, nutritious and easy to grow, rocket can grown from seed to baby greens in only a month. The plants are equally at home in garden beds, containers or hydroponic systems, and in some places wild strains can be foraged as edible weeds.

Modern eaters developed a taste for rocket in the last two decades, but the savoury, slightly peppery leaves have been enjoyed by humans for thousands of years. The ancient Romans regarded rocket leaves dipped in oil and salt as an aphrodisiac, and rocket’s association with sex kept it banned from medieval monasteries. Meanwhile arugula gained wide acceptance in folk medicine from Europe to India, for valid reasons. In addition to an abundance of vitamins C and K, arugula is loaded with minerals and antioxidants known for their impact on cancer, stomach ulcers, and organ health.

“Rocket-flowers” — Rocket flowers are edible too

Types of Rocket

The common names of arugula and rocket encompass three species. All three types of rocket are cool-season crops that grow best in spring and autumn.

Native to the Mediterranean region, the plant known variously as roquette, garden rocket, salad rocket, or Italian arugula (Eruca vesicaria ssp sativa or just Eruca sativa) grows into a rosette of broad, strappy leaves, followed by loose clusters of edible white flowers. The most productive type of arugula you can grow, garden rocket matures almost too quickly in the spring, when days are getting longer and warmer. Autumn crops stand much longer without bolting, and plants often survive winter with protection from animals.

Native to Eurasia and often called wild rocket, perennial wall-rocket (Diplotaxis tenufolia) has smaller, more finely cut leaves, and the plants bloom yellow rather than white. New varieties selected for uniformity and disease resistance like Bellezia and red-variegated Dragon's Fire are among the great new wild arugula cultivars, which you can grow in a garden or better yet, in containers.

A common weed in the western Mediterranean, annual white rocket (Diplotaxis erucoides) is listed as ‘Wasabi arugula’ in seed catalogues because of its strong peppery bite. Wasabi arugula is a short-lived presence in the spring garden because of its propensity to bolt, but can be a big-flavour addition to the autumn salad garden.

Succession Planting with Rocket

All types of rocket are fast, fleeting crops during the first half of summer, when any type of stress (drought, heat, nutrition) combined with lengthening days trigger even young plants to stop growing leaves and concentrate on a tall flowering stalk instead. This process, called bolting, is why it’s important to make several sowings of rocket in spring, three weeks apart. You can make two sowings later in the season, as well. Because rocket is such an outstanding autumn crop, I plant some two months before my first autumn frost date, and more three weeks later.

There is little reason to start rocket indoors because the seeds are very willing germinators, often appearing within 5 days after planting. You can eat tiny seedlings as you thin them, or transplant the extras to a new location, or to containers.

Harvest rocket leaf by leaf, or use scissors to snip off baby rocket just above the plants’ crowns. New leaves will quickly replace the old ones.

“Rocket-in-a-container” — Growing rocket in containers helps keep the leaves clean of soil

Growing Rocket in Containers

Rocket has a small root system, so it is an excellent candidate for containers. In spring and summer, rocket grown in containers is less likely to be bothered by flea beetles, which make numerous small holes in arugula leaves. The leaves of container-grown plants also stay nice and clean since there is so little soil to splash about.

As one of my last acts of the gardening year, I rescue a few rocket garden volunteers by transplanting them to containers to bring indoors. Stationed in a sunny south-facing window, the plants will continue to grow for several weeks, or well into the winter with the help of supplemental lights.

“Saving-arugula-seeds” — Saving rocket seeds is easy if you snip off mature seed pods to let them finish drying indoors

Saving Rocket Seeds

You can turn rocket’s propensity to bolt in your favour by allowing a few plants to bloom and produce seeds. Saving rocket seeds is easy, though the plants often need staking to keep the seed-bearing branches high and dry. Mature seed pods eventually turn from green to brown and shed their seeds. I snip off the seed-bearing branches as they are ready, let them finish drying indoors in a box, and collect enough rocket seeds to replant and share the following year.