(Allium schoenoprasum) This indispensable kitchen herb has a mild onion flavour that is useful in so many dishes. Round, green, strap-like leaves provide multiple harvests throughout the summer. Showy purple flowers are edible as well. Harvest them as they are just starting to open. Cut the flower, separate into florets and sprinkle on salads. Chives are problem free in the garden and are often used as a companion plants to keep insects at bay.