Any plants from the legumes family such as Clover, Sunn hemp or Alfalfa can be used as a cover crop, as their roots are the house for a bacteria called Rhizobium, which specialize in nitrogen fixation and maintenance.
While legumes are often used as the main part of the cover crops, other herbs or flowers can also be added as a companion plant to help repel insects or attract the predators such as Sunflower, Marigolds, Basil and Camomile.
