Stringless varieties include Blue Lake, Maxibel, Top Crop, Kentucky Wonder and Contender. Many types of green beans have a tough fiber or string that runs the length of the bean and is removed prior to cooking. String-less green beans have been developed to not contain the fibrous "string". Idea for cooking, fresh in salads or preserved as pickles.
Half-runner beans are newly developed varieties that are a bush bean with a trailing habit. Favorites include Striped, State and Mountaineer varieties. Do not fertilize green beans. They find enough nutrients from the soil. Excessive fertilization leads to vigorous growth of the plant, but beans do not develop.
There are many varieties of yellow wax beans. Yellow Wax, Golden Wax and Dragon's Tongue varieties are dependable gardening favorites. Round Podded Yellow Beans include Pencil Pod, Golden Crop and Roc D'or varieties. Yellow beans are similar in taste to both green and purple beans, the main difference is color. Yellow beans are used in salads, stir-fry dishes and are often pickled in combination with other garden vegetables.
Purple green beans are attractive in soups, salads and stir-fry dishes. Dependable varieties that are easy to grow include Royalty and Royal Burgundy. Purple beans are especially sweet, with a "nutty" flavor that enhances any dish to which they are added.
French Filet green bean varieties include Straight 'N Narrow, Nickel and Grenoble. Long and narrow, these types of beans are often served as a garnish on salads and steak presentations. These beans should be picked when they are very thin and underdeveloped. Fortex and Emerite varieties are favorites of northeastern gardeners. If you haven't tried Masai beans, sweet, tiny and tender, they are easy to grow in U.S. hardiness zones 5 to 8.
Farmers in Rwanda, South Africa have recently developed 15 new strains of beans, high in protein and easy to grow at low elevations. Two of the new strains, Ngobokaruga and Nyiramata are two of the beans with the highest nutritional value. These beans may be harvested early as "green" beans or allowed to develop to mature pods.