Rocket (Arugula)

Known as Arugula in many parts of the world and Roquette in others, rocket (Eruca vesicaria) is the bold, peppery rebel of the salad garden. Fast-growing and highly rewarding, it is one of the easiest leafy greens a gardener can grow.

What is Rocket?

Rocket is a fast-growing, cool-season edible plant belonging to the Brassicaceae (Cabbage) family, making it a cousin to broccoli, kale, and mustard. It is grown primarily for its deeply lobed, oak-leaf-shaped foliage, which carries a distinctive peppery, nutty, and slightly bitter flavour. As the plant matures — or when stressed by heat — the flavour intensifies significantly.

Appearance

Rocket produces elongated, deeply lobed leaves from a low-growing rosette. When it matures or bolts, it sends up a flowering stalk bearing small, four-petalled white flowers with purple veins, which are also edible and make an attractive garnish.

Flavour Profile

Unlike mild lettuce, rocket demands attention. Young leaves are tender and moderately peppery; older leaves pack a fiery, mustardy punch. The flavour is often described as nutty with a wasabi-like heat, and it balances beautifully with sweet, salty, or acidic ingredients.

Nutritional Value

Rocket is nutrient-dense, providing good levels of Vitamin K, Vitamin C, folate, calcium, and antioxidants, making it a highly worthwhile addition to any kitchen garden.

Culinary Uses

• Fresh salads — pairs well with pears, figs, parmesan, feta, and balsamic dressings
• Pizza topping — scattered fresh over a hot pizza straight from the oven
• Pesto — blended with olive oil, nuts, and cheese for a sharper, zingy alternative to basil pesto
• Lightly wilted — sautéed briefly like spinach, though cooking reduces its peppery bite
• Garnish — the flowers and baby leaves make a stunning plate decoration

How To Grow

How to Grow Rocket

Rocket is one of the most beginner-friendly crops in the garden — fast to establish, unfussy about conditions, and rewarding within weeks. The key to success is timing: rocket thrives in cool weather and sulks in the heat.

Timing

Sow rocket in early spring or autumn for the best results. Midsummer sowings are possible but the plant will bolt rapidly in hot weather. In mild climates, rocket can be sown and harvested almost year-round with the protection of a cloche or cold frame in colder months. Sow in succession every 2–3 weeks to maintain a continuous supply.

Site and Soil

Rocket is adaptable, but performs best in:

• Well-drained, moisture-retentive soil enriched with compost
• Full sun in cool seasons; partial shade during warmer periods to delay bolting
• Containers, raised beds, and windowsill pots — rocket is perfectly suited to small spaces

Sowing Direct

1. Prepare a fine, crumbly seedbed or fill a container with good-quality potting compost.
2. Sow seeds thinly in rows approximately 30cm apart, at a depth of 1cm.
3. For baby leaf rocket, scatter seeds more densely over the surface and rake in gently.
4. Water gently and keep the soil moist until germination, which typically occurs within 5–7 days in warm conditions.

Thinning

Once seedlings are a few centimetres tall, thin them to approximately 15cm apart for full-sized plants. The thinnings are delicious — eat them straight away.

Transplanting

If starting indoors, sow in module trays and transplant when seedlings have 2–3 true leaves, taking care not to disturb the roots.

Watering and Care

• Water consistently — irregular watering causes stress and accelerates bolting
• No feeding required for short crops, though a light nitrogen feed can encourage leafier growth
• Apply a mulch around plants to retain soil moisture and suppress weeds
• Cover with fine mesh netting to protect against flea beetles, which are the most common pest

Dealing with Bolting

If a thick central stem with flower buds appears, your rocket is bolting. To manage this:

• Remove the flower stalk immediately and harvest all remaining leaves
• The flowers are edible and work well in salads
• Allow one or two plants to set seed for a self-sown "free" crop in the following season

Harvesting

Harvesting Rocket

Rocket offers flexibility at harvest time — you can take a little regularly or a lot all at once. Choosing the right method depends on how long you want to keep the plant producing.

Method 1: Cut-and-Come-Again (Recommended)

This is the most productive harvesting approach.

• When: Begin harvesting when outer leaves reach 8–10cm in length.
• How: Use scissors or garden snips to cut individual outer leaves or a whole row of leaves, cutting approximately 2cm above the soil surface.
• Key: Leave the central growing point (the small, pale inner leaves) completely intact — the plant will regenerate a new flush of leaves within days.
• Frequency: Harvest every 5–7 days for a continuous supply.

Method 2: Baby Leaf Harvest

Ideal for tender, mild-flavoured leaves.

• When: When seedlings reach just 4–5cm tall.
• How: Shear across the entire patch with scissors, removing the top half of the growth.
• Result: Extremely tender leaves with a milder peppery flavour. Plants will usually regrow for a second cut, though subsequent growth tends to be spicier.

Method 3: Whole-Plant Harvest

Best when the plant is starting to bolt or you need to clear the space.

• When: Any time before flowering begins in earnest.
• How: Pull the whole plant up by the roots, or cut cleanly at the base with a knife.
• Tip: Stand uprooted plants with their roots in a small amount of cold water in the refrigerator to extend crispness.

Harvesting Tips

• Harvest in the morning when leaves are at their most turgid (crisp and hydrated) for the longest shelf life.
• Watch for bolting: Once a thick central stalk appears, harvest all leaves immediately as quality deteriorates quickly.
• Eat the flowers: Rocket flowers carry a mild, peppery-sweet flavour and make an attractive garnish on salads and pasta dishes.

Storage

Rocket wilts quickly after harvest. For best results:

1. Rinse in cold water and spin or pat dry.
2. Wrap loosely in a damp cloth or paper towel.
3. Store in an airtight bag or container in the refrigerator.
4. Use within 4–5 days for the best flavour and texture.

Common Problems

Common Problems with Rocket

Bolting (Going to Seed)

Bolting is the most frequent issue growers face. When temperatures rise or day length increases, rocket sends up a flowering stalk, causing leaves to become tough, very peppery, and unpalatable. To delay bolting, choose bolt-resistant varieties, sow in spring or autumn rather than midsummer, and provide partial shade during warm spells. Harvest regularly to slow the process.

Flea Beetles

Tiny holes peppered across the leaves are the telltale sign of flea beetles. These small, jumping insects are especially damaging to young seedlings. Protect crops with fine insect-mesh netting from the moment of sowing. Keeping the soil moist also deters them, as they prefer dry conditions.

Aphids

Greenfly and other aphids may cluster on young growth and under leaves, causing distortion and stunted growth. Blast them off with a strong jet of water, or encourage natural predators such as ladybirds and lacewings by planting companion flowers nearby.

Downy Mildew

In cool, damp, poorly ventilated conditions, rocket can develop downy mildew, appearing as yellowing on the upper leaf surface with grey-white fuzz beneath. Improve air circulation by thinning plants and avoid overhead watering. Remove and dispose of affected leaves promptly.

Slugs and Snails

In wet conditions, slugs and snails can shred young rocket leaves overnight. Use physical barriers such as copper tape around containers, crushed eggshells, or set out traps. Check under pots and debris regularly.

Caterpillars

As a member of the Brassicaceae family, rocket can be attacked by cabbage white butterfly caterpillars. Inspect the undersides of leaves for egg clusters and remove by hand, or use fine mesh netting as a physical barrier.