Yardlong Beans

Chinese yardlong beans rarely grow a yard long, but they get close. These impressive beans are fun to grow and delicious to eat.

​Also known as asparagus beans, snake beans, and Chinese long beans, these annual legumes are a variety of cowpea, rather than a type of green bean. 

Yardlong beans (Vigna unguiculata subs. sesquipedalis) are staples in Asian stir fry. They are easy to grow, highly productive, and they really make a statement.

​How yardlong beans grow

Climbing vines provide the elevation needed for these dangling beans. Vines can reach 12’ in length. Compound leaves have 3 heart-shaped leaflets and are bright green. Understated white, pink, or lavender flowers look similar to other legumes, with five petals, the largest being on top. As legumes, yardlong beans have a mutually beneficial arrangement with certain soil microorganisms which allows them to use nitrogen from the atmosphere.

Red noodle bean in raised bed

Yardlong bean varieties

There are several varieties of yardlong beans, with varying maturity dates, colors, and growth habits. Here are just a few:

• liana - early producer (70 days)
• purple podded - loves high temperatures and retains its color when cooked (90 days)
• red noodle beans (my favorite!) - similar to purple podded by crunchier (95 days)
• stickless wonder - dwarf vines do not need trellising; earlier, shorter season (40 days)
• tiger asparagus beans - white with red mottling; dwarf variety

How to grow yardlong beans

Yardlong beans need lots of sun and heat and something to climb (unless it’s a dwarf/bush variety). Seeds should be planted 1” deep, well after the last frost date, and next to trellising, a stock panel, a tuteur, or some other structure. Yardlong beans prefer slightly alkaline soil with a pH of 6.0 to 7.5. You may want to succession plant at 2-week intervals for maximum harvest.

Red noodle beans growing on trellis

At first, it won’t look like much is happening. It may take 60 to 90 days before beans start flowering. Once they start, however, they are very productive. Bean pods tend to form in groups of two or more and they are a striking addition to any garden. And they taste good!

Harvested red noodle beans

Harvesting yardlong beans

Yardlong beans are generally eaten before they reach full size. This means checking every day during peak production. They taste their best when about the diameter of a pencil. If you leave them on the vine longer than that, production will slow and the beans will become tough. You can, however, allow them to get close to full maturity and then harvest the beans for food and next year’s crop. Just be careful when harvesting. Do not damage the buds from which the beans grow. These buds can produce multiple beans throughout the growing season.

You can store yardlong beans in the refrigerator for several days before adding them to stir fry, casseroles and soups. These beans do not steam well.

Yardlong bean pests and diseases

Yardlong beans are not as susceptible to bean weevils as other bean species. Ants, aphids, and thrips, however, can cause problems. The most common pests are herbivores, such as rabbits, voles, and deer.

Delicious and attractive, yardlong beans also attract pollinators. Give them a try!