Fennel, (Foeniculum vulgare L. and F. spp.) both bronze and green, are perennials in the garden, providing splendid additions to salads.  Try fennel seed in sauces, on pizza.  Roasted fennel seeds are a sub-continent Asia treatment for indigestion and flatulence.  (More) 
Cut this fennel just above the soil and cook with salmon.  If cut just above the soil you will not kill the plant.