PERENNIAL WALL ROCKET Diplotaxis tenuifolia

Found in the wild growing in waste ground and from cracks in walls, but will grow anywhere warm and free draining. A lush, edible green herb with cheerful yellow flowers, this is the same species widely cultivated as salad or wild rocket. Its simple flowers are popular with pollinators. 

Height: up to 80cm

Flowers: May to September

Colour: yellow