Eruca vesicaria aka Arugula

Eruca vesicaria, known as rocket or arugula, is an annual vegetable. It belongs to the mustard family, Brassicaceae. Kew places its native range in Spain, Morocco and Algeria. NC State gives a wider range reaching China and Arabia. It grows in fields, olive groves and on stony hills. It also grows beside tracks and on waste ground. Gardeners grow it for its sharp, peppery taste.

Plants grow upright and branch as they develop. Garden heights range from about 0.7–3.3 feet [0.2–1 metre]. Plants For A Future describes a height near 2 feet [0.6 metres]. Spread can reach about 1.6 feet [0.5 metres]. The green leaves feel fleshy and grow alternately along stems. Basal leaves have several side lobes and one large end lobe. Smaller stem leaves have smooth edges. The stems are green and lack an aromatic scent.

Flowers appear in summer, often as heat ends leaf growth. Each flower has four petals arranged like a cross. Petals may be white, cream or pale yellow. Dark red or purple veins mark their surface. Flowers grow in clusters and have yellow stamens. Green fruits form long pods with pointed tips. These siliquae hold seeds in two rows. The flowers, young pods and seeds are edible.

Rocket grows best in cool weather, during spring and fall. Give it full sun and rich, moist soil that drains well. Partial shade can help delay flowering in hot climates. It grows in sand, loam, clay and chalk. RHS lists acid, neutral and alkaline soils as suitable. NC State lists USDA zones 2–11 and tolerance of light frost. RHS gives a UK hardiness rating of H6. Sow seeds directly, or start them indoors for later planting. Plants grow fast and can yield leaves after six weeks.

Rocket suits food gardens, pots and informal garden beds. Young leaves work in salads or cooked dishes. Older leaves and pods become tough or bitter. Flowers add the same peppery taste to salads. Pick leaves as needed because they store poorly after harvest. Repeated sowings can extend the harvest season. Plants For A Future reports past medicinal uses for leaves and seeds. Seed oil also has uses in soap, lighting and lubricants. That source lists no known hazards. Serious health problems are few, but aphids and flea beetles may attack. Leaf spot, powdery mildew and seedling damping-off can also occur. Plants may self-seed, but NC State reports little risk of escape.