Perennial Wall Rocket - Diplotaxis tenuifolia
Reseeding biennial. Cold hardy to zone 5 (or lower). Very easily grown from seed. Makes for a good addition to the salad garden. Sometimes called “wild Italian arugula” because of its spicy arugula tasting leaves and prevalent reseeding in poor soils and sidewalk cracks. Has small yellow flowers that can be added as garnish to salads. Abundant seeds can be saved and used for winter sprouts.