Vegetable · Fabaceae
Runner Bean
Phaseolus coccineus
Point it at the sun, give it something tall to climb and plenty of water, and this fast, generous climber runs until frost.
Full sun
Every 3–7 days
50–77°F · 10–25°C
65–75 days
Overview
The runner bean gets going in a hurry, twining upward and cropping hard, and it earns its keep with flowers as much as with its long, tender pods. It sits in the bean family, and here is the twist: in mild zones 7 to 11 the fleshy roots pull through winter and it comes back as a perennial, though plenty of growers just run it as an annual. Stake up a tall support and watch it shoot 6 to 10 feet in a single season.
Flowers pour out from early summer to the first frost in scarlet, white, or a painted pink-and-white blend, and they pull in bees and hummingbirds all season long. Every bloom that sets swings into a green pod you snap off young. Let one linger and it toughens, but that is no loss, since the mature seeds shell straight out for fresh or dried beans.
Best of all, this crop pays back a beginner. It makes its own nitrogen, so it barely needs feeding, and it climbs on its own the moment you give it a grip. Hand it cool summers and even moisture and it will keep flowering, since heat is the one thing that shakes the blooms loose before they set.
Care
The short version: plant runner beans in full sun on a tall support, keep the fertile, well-drained soil evenly moist at about 1 inch of water a week, and feed them lightly, since they fix their own nitrogen.
Light
Give runner beans full sun and nothing less, since shade is nowhere on their tolerated list. That flood of light is exactly what fuels the fast climb and the steady stream of flowers, so hand them the brightest patch going.
Water
Pour on about 1 inch of water a week and hold the soil evenly moist, above all while the vines flower and set pods. Sandy ground drains quick, so water it more often. Keep that moisture rolling and the flowers hang on even when the weather warms up.
Soil
Set them into fertile, well-drained loam at pH 6.0 to 7.0. Dig in some compost before you sow and the deep, driving roots take it from there.
Temperature
They power along between 50°F and 77°F (10°C to 25°C), and a cool summer is where they shine. Push past that and the flowers start dropping before they can set, so watch the heat.
Humidity
Skip the fuss over humidity, since everyday outdoor air at 40% to 70% covers it easily. Just space the plants so air can rush through the leaves.
Feeding
Feed with a light touch, because these plants make their own nitrogen. A quick 5-10-10 at planting does the job, and pile on more nitrogen and you grow leaves instead of the beans you want.
Pruning
There is next to no pruning to keep up with. Once a vine tops its support, pinch out the growing tip to fire up branching and pod set, and keep pulling spent pods to drive the harvest on.
Repotting
Containers are not this plant's game. Sow it straight into the garden at the base of a tall support and let it climb instead of penning it in a pot.
Size & spacing
These vines charge up 6 to 10 feet (1.8 to 3 m) while keeping a tight base, spreading just 12 to 24 inches (30 to 60 cm). Stake a strong tall support and leave room for air to move through the leaves.
When to plant
Warm soil is the green light. The moment the last spring frost clears and the ground hits 50°F to 60°F (10°C to 16°C), sow straight into the bed, and you will be snapping off young pods about two months later, right up to frost.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Optional: 2-3 weeks before the last spring frost in biodegradable pots to avoid root disturbance.
- Plant: After the last spring frost, once soil is at least 50-60°F (10-16°C).
- Harvest: Flowers from early-to-mid summer until frost; harvest young pods (10-15 cm / 4-6 in) about 65-75 days after sowing.
Hardiness
USDA hardiness zones: 7–11
Temperature: down to -18°C
Troubleshooting
Runner beans flag their trouble fast, and it turns up at the flowers, the pods, or the leaves. Catch the signal early and you can jump in before it dents the harvest. Find the match below and get to work while it still pays off.
Flowers fall in the heat and leave no pods
That is blossom drop, and heat is the culprit almost every time. Once the days blow past 80°F to 90°F (27°C to 32°C), the pollen quits and the flowers drop before they can set. Keep the roots cool and evenly watered, throw a bit of afternoon shade over the plants in a heat wave, and pod set fires right back up when the weather cools.
Fix:
- Keep soil evenly moist and mulch to moderate root-zone temperature
- Provide light afternoon shade during heat waves
- Wait for cooler weather, when pod set typically resumes
Leaves get chewed to lace or curl and distort
Lacy leaves with yellow grubs stuck underneath call out the Mexican bean beetle, and curled new growth crawling with soft insects flags aphids. Pick off the beetles, grubs, and orange egg masses, blast the aphids with a hard jet of water, and bring in insecticidal soap only when an infestation really takes hold. Scout often, throw row fabric over young plants, and put the lady beetles to work.
Fix:
- Hand-pick beetles, larvae and egg masses
- Dislodge aphids with a strong spray of water
- Apply insecticidal soap to heavy infestations
Pods turn tough and stringy
Leave pods hanging too long and they go over-mature, packing on the fibers and strings that make them snap instead of bend. Beat it by picking young at 4 to 6 inches (10 to 15 cm) and scanning the plants every 2 to 3 days so none get away. Any that do still shell out fine for fresh or dried beans.
Fix:
- Harvest pods young, at 10-15 cm (4-6 in)
- Pick every 2-3 days to catch pods at peak tenderness
Toxicity
Dig in with confidence: the cooked pods and beans are great eating, and the growing plant is no danger to pets or livestock. The single thing to track is raw mature beans, which carry a lectin called phytohaemagglutinin that can turn a stomach, so cook the dried seeds right through and stash them where a cat or dog cannot grab them raw.
Toxic to
Cats · Dogs
Safe for
People · Horses · Rabbits · Livestock · Birds
Cats Caution
Cats are not flagged as at risk here, and most breeze right past the plant. The one thing to track is raw mature beans, whose lectin can hand a cat vomiting or diarrhea after a few, so keep dried seeds out of reach.
Dogs Caution
Runner beans are no known poison for a dog, but one that wolfs down raw dried beans can pick up an upset stomach from the same lectin. Cooked pods and beans are fine, so it is only the raw mature seeds to lock away.
Horses Safe
A horse grazing close by faces nothing dangerous in this plant. As with any legume, hold back big amounts of raw dried beans, but the growing plant itself is not toxic.
Rabbits Safe
Rabbits can crop the foliage without any harm. Just keep them off the raw mature seeds, which pack the same lectin that troubles other animals, and let them tuck into leaves and young pods.
Livestock Safe
Cattle, goats, and sheep run no risk from the living plant. The lone caveat is feeding quantities of raw dried beans, which should be cooked rather than served raw.
Birds Safe
Backyard birds and poultry do just fine around runner beans. Do not toss them raw dried beans in bulk, since the uncooked seed is rough on the gut, but pods and foliage are no trouble.
People Safe
For people, cooked pods and beans are a kitchen win and totally safe. Raw mature beans are the exception, since they pack phytohaemagglutinin, so always cook dried seeds through before they hit the plate.
Raw or undercooked mature (dry) seeds contain phytohaemagglutinin, a lectin that can cause nausea, vomiting and diarrhea if eaten in quantity; cook seeds thoroughly. Young pods, cooked, are safe.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Only a short lineup of runner beans is worth chasing, split by flower color and by whether you grow them to eat, to enjoy, or both. Here are the standouts to seek out.
Scarlet Emperor
A go-to scarlet-flowered heirloom that hits maturity in about 75 days and keeps long green pods rolling in heavy flushes.
Painted Lady
An ornamental crowd-pleaser grown for its red-and-white bicolor flowers just as much as for its beans.
White-flowered (e.g. 'Czar' / 'Albus')
A double-duty type with white flowers and large white seeds that delivers both as a fresh pod and as a shell bean.
Companions
Runner beans shine in the Three Sisters planting, climbing the corn for support and feeding nitrogen back to it and the squash sprawling below.
Plant near
corn: In the Three Sisters planting, corn stalks give the climbing beans a natural support while the beans fix nitrogen for the corn.
squash: Part of the Three Sisters; sprawling squash shades the soil and deters pests while the beans climb the corn and fix nitrogen.
How to propagate
Starting runner beans is a thrill precisely because it is so easy. Drop the seed right into warm soil and it powers up on its own, no soaking or chilling needed.
SeedEasy
Direct-sow outdoors after the last spring frost once soil reaches at least 50-60°F (10-16°C). · Germinates in 7-14 days; begins flowering about two months after sowing.
Drive the seeds in 1 to 1.5 inches (2.5 to 4 cm) deep right at the base of a tall support, once the frost clears and the soil warms to 50°F to 60°F (10°C to 16°C). They punch up in 7 to 14 days and start flowering about two months on, so there is no need to rush them under cover, though a sowing 2 to 3 weeks early indoors gives you a jump. In mild zones you can even lift the tuberous roots in fall and overwinter them for a faster crop the following year.
Myths
Runner beans are poisonous and off-limits at the table.
Cooked young pods are a plain, everyday vegetable that gardeners grow and eat everywhere. The only real danger sits in raw or undercooked mature dry seeds, which hold phytohaemagglutinin and can upset the gut. Cook the dried beans through and they are safe to eat.
Runner beans need a heavy nitrogen feed to crop well.
Like all legumes, they grab their own nitrogen from the air through Rhizobium bacteria in the roots, so they ask for next to nothing. Overdo the nitrogen and you get leaves, not beans, because that lush growth muscles out the pods.