Nasturtium is known for its warm cheerful flowers which are often used as a culinary garnish. All parts of the plant are edible, and have a peppery taste similar to watercress. Sow nasturtiums around the base of fruit trees to deter codling moth, woody aphids and borers. Alternatively, make an insect controlling spray by infusing nasturtium leaves in boiling water. Nasturtium is also grown as a companion plant to vegetables to improve pest resistance.
from Northey St City Farm News – JUNE 2014