Up to 90 days. Fava beans are a popular type of bean all around the world. Growing in stalks that can reach up to six feet, pods are accompanied by white and dark flowers, which pollinators are drawn to. Fava beans thrive in cooler temperatures, making them great for fall planting. In addition to producing delicious beans, tilling the stalk’s cover crop into the soil can release the nitrogen content of the stalk, making this a very practical addition to your garden.Also great as a cover crop to add nitrogen to the soil.