VegetablelegumeStraightforward

Runner bean

Phaseolus coccineus

A tuberous perennial from Central America, grown as an annual because British winters kill the top growth. It produces an enormous crop from a small footprint of ground and is the traditional backbone of the allotment. Its one vulnerability is pod set: runner beans depend on insects, and in a hot dry spell the flowers drop without setting, which is a pollination and humidity problem rather than a feeding one.

Position: Full sun or Partial shade
Water: high demand
Drainage: Moisture-retentive
Grows to: 200–300 cm × 30–45 cm
Hardiness: H2
Harvest: July to October
Difficulty: Straightforward

Described view

A double row of runner beans climbing a wigwam of canes tied at the top, in full flower and carrying young pods

August

In flower · Harvest

Runner bean’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

Activity	M	A	M	J	J	A	S	O
Sow under cover	March.	April.
Sow outdoors			May.	June.
In flower					July.	August.
Harvest					July.	August.	September.	October.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Sow under cover
2–4 weeks before your last spring frost
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Runner beans — sowing
Checked 2026-08-13
Sow outdoors
1–6 weeks after your last spring frost
source
Sourced guidancehigh confidence
- Royal Horticultural Society: Runner beans — sowing outdoors
Checked 2026-08-13

Conditions it needs

Light: Full sun, Partial shade
Direct sun: 5 hours a day or more
Frost: Frost tender
Hardiness rating: H2 (RHS)
Grows best at: 15–25 °C
Germinates at: 12–25 °C
Soil: Loam, Clay, Silt
Soil pH: 6–7
Drainage: Moisture-retentive
Water needs: high
Drought: poor tolerance
Waterlogging: poor tolerance
Heat: moderate toleranceHorticultural consensusDepends on conditions
Wind and exposure: poor tolerance

Where these figures come from

LightSourced guidancehigh confidence

Royal Horticultural Society: Runner beans — position

Checked 2026-08-13

Direct sunHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

FrostSourced guidancehigh confidence

Royal Horticultural Society: Runner beans — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancehigh confidence

Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Grows best atHorticultural consensusmoderate confidence

Copes with cooler conditions than French beans, which is why it does better in a poor British summer.

No external citation — see the evidence type above.

Checked 2026-08-13

Germinates atSourced guidancehigh confidence

OSU Extension Service — Oregon State University: Vegetable seed germination temperatures

Checked 2026-08-13

SoilSourced guidancehigh confidence

Deep soil with plenty of organic matter, which is what the traditional bean trench is for.

Royal Horticultural Society: Runner beans — soil

Checked 2026-08-13

Soil pHSourced guidancehigh confidence

University of Minnesota Extension — University of Minnesota: Soil pH for vegetable crops

Checked 2026-08-13

DrainageHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Water needsSourced guidancehigh confidence

Royal Horticultural Society: Runner beans — watering

Checked 2026-08-13

DroughtHorticultural consensusmoderate confidence

Royal Horticultural Society: Runner beans — watering

Checked 2026-08-13

WaterloggingHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

HeatHorticultural consensusDepends on conditionsmoderate confidence

Applies when: The plant tolerates heat; the FLOWERS do not set well above about 30 °C or in dry air, which is what causes the familiar failure to pod.

Royal Horticultural Society: Runner beans — flower drop

Checked 2026-08-13

Wind and exposureHorticultural consensusmoderate confidence

A cropping runner bean row presents a large sail; wind can take the whole structure down.

No external citation — see the evidence type above.

Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Runner bean will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Works, with one condition	Runner bean will crop on sandy, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Chalky and alkaline	Struggles here	Runner bean struggles on chalky and alkaline: The soil is substantially too alkaline for it: it wants pH 6 to 7, and this soil sits around 7.8 to 8.5. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering. A container or a raised bed of imported soil sidesteps the problem entirely.
Loam	Prefers this soil	Loam suits Runner bean as it stands: The pH suits it: it wants 6 to 7, and this soil is in that range. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Silty	Prefers this soil	Silty suits Runner bean as it stands: The pH suits it: it wants 6 to 7, and this soil is in that range. Silt is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Peaty and acid	Works, with one condition	Runner bean will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Works, with one condition	Runner bean will crop on shallow over rock, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Made ground and urban soil	Works, with one condition	Runner bean will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height: 200–300 cm
Mature spread: 30–45 cm
Rooting depth: 60 cm
Spacing: 15–20 cm apart
Row spacing: 60 cm

Where these figures come from

Mature heightSourced guidancehigh confidence

Royal Horticultural Society: Runner beans — supports

Checked 2026-08-13

Mature spreadHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Rooting depthHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

SpacingSourced guidancehigh confidence

Royal Horticultural Society: Runner beans — spacing

Checked 2026-08-13

Row spacingSourced guidancehigh confidence

Between the two rows of a double row; leave 1.5 m between structures for access and light.

Royal Horticultural Society: Runner beans — spacing

Checked 2026-08-13

Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

In a container

Minimum volume: 30–40 litres
Minimum depth: 35 cm

Where the container figures come from

Minimum volumeSourced guidancehigh confidence: Royal Horticultural Society: Runner beans in containers
Checked 2026-08-13
Minimum depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Possible with a large tub and a firmly anchored structure, but the water demand of a fully grown plant makes it hard work.

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

Method	Suitability	What it needs
Open ground	Well suited source Sourced guidancehigh confidence Royal Horticultural Society: Runner beans Checked 2026-08-13	A support structure to 2.5 m, firmly anchored; Deep soil enriched with organic matter
Traditional dug bed	Well suited source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13
Raised bed	Workable source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	A structure the bed can anchor against wind
Container	Workable Horticultural consensusDepends on conditionsmoderate confidence Applies when: Needs a very large container and daily watering; the plant is far bigger than a pot suggests. Royal Horticultural Society: Runner beans in containers Checked 2026-08-13
Vertical growing	Workable source Horticultural consensusmoderate confidence A vigorous natural climber, given something strong enough. No external citation — see the evidence type above. Checked 2026-08-13
Polytunnel	Workable source Sourced guidancemoderate confidence Agriculture and Horticulture Development Board — AHDB: Runner beans — flower set Checked 2026-08-13
Hydroponics	Marginal source GrowingHQ editorial positionmoderate confidence Two and a half metres of growth and a flower that needs a bumblebee to trip it. Indoors the plant grows and does not set, which is the same failure it has under glass and for the same reason. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13
Greenhouse	Marginal source Sourced guidancemoderate confidence Agriculture and Horticulture Development Board — AHDB: Runner beans — flower set Checked 2026-08-13
Windowsill	Not suitable source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13

Growing it

SupportBuild the structure before sowing, to at least 2 m, and anchor it properly. A row of runner beans in full leaf catches wind like a fence, and a collapsed structure in August ends the crop.
WateringWater generously and consistently once flowering starts. Runner beans are the thirstiest crop in this catalogue at that stage, and dry roots show up as dropped flowers within days.
PollinationRunner beans need insects to set pods, unlike French beans. Flowers that drop without setting in a hot dry spell are a pollination and humidity problem: damping the plants down in the evening helps, and there is nothing to be gained from feeding.
HarvestingPick every two or three days from the moment the first pods are usable. A runner bean allowed to mature seed shuts down flowering across the whole plant, and this single habit decides whether the row crops for six weeks or twelve.
FeedingRunner beans crop for months and want a rich, moisture-holding root run prepared with compost before planting rather than feeding afterwards. Where the soil is thin, a high-potassium liquid feed once flowering starts helps the set; nitrogen at that stage gives leaf and no beans.
ProtectionThe top growth is killed by the first frost, but runner beans are perennial below ground and the tuberous roots can be lifted and stored dry in a frost-free shed, then replanted in spring for an earlier crop. Most growers do not bother — fresh seed is cheap and stored roots often rot — so treat it as an option rather than the standard practice. As with French beans, cut the haulm off and leave the roots in the ground for their nitrogen.

Where this guidance comes from

SupportSourced guidancehigh confidence: Royal Horticultural Society: Runner beans — supports
Checked 2026-08-13
WateringSourced guidancehigh confidence: Royal Horticultural Society: Runner beans — watering
Checked 2026-08-13
PollinationSourced guidancehigh confidence: Royal Horticultural Society: Runner beans — flowers not setting
Checked 2026-08-13
HarvestingSourced guidancehigh confidence: Royal Horticultural Society: Runner beans — harvesting
Checked 2026-08-13
FeedingSourced guidancemoderate confidence: Royal Horticultural Society: Runner beans — cultivation
Checked 2026-08-13
ProtectionSourced guidancehigh confidence: Royal Horticultural Society: Runner beans — cultivation
Checked 2026-08-13

Is it worth putting under cover?

Whether it will grow there is on the methods table above. This is whether the space is well spent, which is a different question and usually the one being asked.

Structure	What protection is worth	What decides it
Greenhouse	Worse under cover source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Flower set. Runner beans drop their flowers above roughly 30 °C and depend on bumblebees to trip them, and a closed greenhouse in July supplies the heat and withholds the bees.One of the few crops in this catalogue that reliably does WORSE under glass than in the open, and it is worth knowing before rather than after.
Polytunnel	No real benefit source GrowingHQ editorial positionmoderate confidence What protection is worth for this crop, judged against the same standard as every other record in this file. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13	Flower set, which a tunnel handles better than a greenhouse because doors at both ends move air and let bees through.

Growing it without soil

Nearly anything can be grown in a soilless system by somebody with enough equipment. The useful question is whether it is worth it, in which technique, and what goes wrong.

Not worth it

It can be made to grow, but a soilless system is the wrong tool — usually because of rooting volume, running cost, or a result no better than a pot of compost.

source

GrowingHQ editorial positionmoderate confidence

Two and a half metres of growth and a flower that needs a bumblebee to trip it. Indoors the plant grows and does not set, which is the same failure it has under glass and for the same reason.

GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

The pollination failure is the same one it has under glass, which makes it a consistent finding rather than a guess.

Techniques that suit it

Drip-fed mediumSolution is dripped into an inert medium around each plant. The most forgiving technique and the one that suits large, long-season, heavy crops.

Horticultural consensusDepends on conditionsmoderate confidence

Applies when: Only with a full-height frame, and the pollination problem remains.

No external citation — see the evidence type above.

Checked 2026-08-13

Root space: Large.
pH band: 5.5–6.5

Where these figures come from

Root spaceHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

pH bandSourced guidancehigh confidence

Outside roughly this band, individual nutrients become unavailable even when they are present in the solution — which is why a crop can starve in a full reservoir.

Purdue Extension — Purdue University: Hydroponic solution management — pH

Checked 2026-08-13

No nutrient recipes here

GrowingHQ records pH bands, which are measurable properties of nutrient availability, and deliberately records no EC or PPM targets and no mixing instructions. Published targets vary by cultivar, growth stage, water source and technique, and the figures that apply to your system are on the product you bought.

Harvesting

Time from sowing or planting: 12–16 weeks

source

Sourced guidancehigh confidence

Royal Horticultural Society: Runner beans — timing

Checked 2026-08-13

When it is readyPick while the pods snap cleanly and before the beans inside swell and show through. Stringy, bulging pods have been left too long.
How to pick itSnip or pinch the stalk to avoid tearing the vine.
Keeping itBest eaten fresh; freezes acceptably after blanching, though the texture softens.

Where the harvest guidance comes from

When it is readySourced guidancehigh confidence: Royal Horticultural Society: Runner beans — harvesting
Checked 2026-08-13
How to pick itHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Keeping itHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Keep picking

Regular picking keeps this plant producing. Fruit or leaves left to mature signal it to slow down or stop.

What goes wrong

Problem	How often	Notes
Pea and bean weevil	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Notched seedling leaves in a cold late spring. Rarely worth acting on.
Slugs and snails	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	On young plants at the base of the supports.
Aphids	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Blackfly on the growing tips in early summer.
Poor fruit set	common source Sourced guidancehigh confidence Royal Horticultural Society: Runner beans — flowers not setting Checked 2026-08-13	Flowers dropping without setting pods in hot dry weather — a pollination and humidity problem rather than a feeding one.

Grown with, grown after, grown instead

Every relationship states its mechanism. A pairing nobody can explain is a pairing nobody has checked, and it does not go in.

Closely relatedFrench bean
A different Phaseolus species grown the same way, but insect-pollinated rather than self-pollinating and more tolerant of cool conditions — which is why runner beans crop in British summers that French beans struggle with.
source
Sourced guidancehigh confidence
Royal Horticultural Society: Beans
Checked 2026-08-13

Safety and edibility

Preparation
The mature dried seeds of runner beans, like other Phaseolus beans, contain lectins and must be cooked thoroughly before eating. Young pods cooked normally are not a concern.
source
Sourced guidancemoderate confidence
- Home and Garden Information Center — Clemson Cooperative Extension: Dry bean safety
Checked 2026-08-13
If saving mature beans to eat dried, soak them, discard the water, and boil vigorously for at least ten minutes before any slower cooking.

Sources for this page

Agriculture and Horticulture Development Board · GrowingHQ editorial synthesis · Home and Garden Information Center · OSU Extension Service · Royal Horticultural Society · University of Minnesota Extension

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-13.

If something is wrong with it

Flowers dropping without setting fruit — 2 causes GrowingHQ holds for runner bean

Something else? Work through it with the diagnostic tool.