Overview
What green beans need, when they crop, and whether they suit your space.
Green beans are one of the most rewarding crops you can sow: big seeds, fast growth, and pods about eight weeks later. They have one demand, warmth. Sow into cold, wet soil and the seed rots. Wait until the soil reaches 16 °C (60 °F), keep plants watered while they flower, and pick every few days so they keep producing.
Quick facts
- Botanical name
- Phaseolus vulgaris
- Soil pH
- 5.8 – 6.5
- Feeding
- Light feeder
- Temperature
- 16 – 24 °C
- Hardiness
- Any zone, as an annual
- Time to harvest
- 50 – 65 days
- Height
- Up to 200 cm (79 in)
- Propagation
- Seed
Optimal growth
Killed by frost
Growing details
- Germination
- 7 – 10 days
- Spacing
- 10 cm (4 in)
- Sowing depth
- 25 mm (1 in)
- Frost sensitivity
- Frost tender
Growing calendar
- Start indoors: April, May
- Sow outdoors: May, June, July
- Transplant: May, June
- Harvest: July, August, September, October
One seed per deep module from late April (RHS), for an earlier crop. Once frost has passed and the soil is 16 °C (60 °F); every 2 to 3 weeks until mid-July. After the last frost, usually late May or early June in the UK. About 8 weeks after sowing; pole beans until the first frost.
Is this plant right for you?
- Fast crop
- Beginner friendly
- Good in pots
- Needs warm soil
- Climbing or bush
- Fixes nitrogen
- Frost tender
Good to know
Plan for support early: this plant needs a stake, cage or frame once it gets going. Wait until the last frost has passed before it goes outside.
Before You Grow
Choose bush or pole beans, and a warm, sunny, sheltered spot with fertile soil.
In the UK these are French beans; in the US, snap, string or wax beans. All are Phaseolus vulgaris.
What you need
Seed
Bush or pole, in green, yellow or purple. See choose your beans.
A warm, sunny spot
Sheltered from wind. See where they grow best.
Compost
Two bucketfuls per square metre forked in. See soil.
Tall supports for pole beans
Canes or poles 2 to 2.5 m (7 to 8 ft) tall. See how to plant.
Twiggy sticks for bush beans
Optional, to hold plants up and pods off the soil.
Slug protection
Young plants are a favourite. See pests.
Choose your beans
Green, snap, string, wax and French beans are all the same plant, Phaseolus vulgaris, eaten as young pods. Modern varieties are stringless.
Bush (dwarf) beans grow 30 to 60 cm (1 to 2 ft) tall with no support. They crop early, about 50 to 60 days from sowing, but only for two or three weeks, so sow again every few weeks. Good in pots. Examples: ‘Provider’, ‘Contender’ and ‘Tendercrop’ (Clemson, Utah State).
Pole (climbing) beans climb 2 m (6 ft) or more and need tall supports. They start later but crop for five or six weeks, until frost if you keep picking, and give more beans for the space. Examples: ‘Blue Lake’, ‘Kentucky Wonder’, and the RHS AGM ‘Cobra’.
Half-runners fall between the two, with runners about 90 cm (3 ft) long.
Colour and shape. Yellow wax and purple pods (‘Purple Teepee’, ‘Red Swan’, which turn green when cooked) stand out among the leaves at picking time. Flat Romano and thin filet types are other choices.
Resistance. In the US, Clemson recommends varieties resistant to bean common mosaic virus and anthracnose.
Bean types compared
-
Bush (dwarf)
- Height
- 30 to 60 cm (1 to 2 ft)
- First picking
- 50 to 60 days
- Cropping period
- 2 to 3 weeks
- Examples
- ‘Provider’, ‘Contender’, ‘Tendercrop’
-
Pole (climbing)
- Height
- 2 m (6 ft) or more
- First picking
- Later
- Cropping period
- 5 to 6 weeks, to frost
- Examples
- ‘Blue Lake’, ‘Kentucky Wonder’, ‘Cobra’
-
Half-runner
- Height
- Runners about 90 cm (3 ft)
- First picking
- Between the two
- Cropping period
- Heavy yields
- Examples
- Grown like bush beans
-
Yellow or purple
- Height
- Bush or pole
- First picking
- As green types
- Cropping period
- As green types
- Examples
- ‘Golden Gate’, ‘Purple Teepee’, ‘Red Swan’
From the RHS, Iowa State, Utah State and Clemson. For a small plot or a pot, bush beans sown every few weeks; for the biggest crop from little ground, pole beans.
Where beans grow best
Beans are tender, warm-season plants: frost damages them and cold soil stops them.
Temperature. They grow best at average temperatures of 16 to 24 °C (60 to 75 °F) (Clemson). Seed needs soil of at least 16 °C (60 °F) at 10 cm (4 in) deep, and seedlings emerge in 7 to 10 days at 18 to 29 °C (65 to 85 °F) (Utah State).
Heat. Above about 32 to 35 °C (90 to 95 °F), especially with dry wind, flowers drop without setting pods (Clemson, Utah State). Plants start setting again when it cools.
Sun. Full sun: at least six hours a day, and UMD prefers eight to ten.
Shelter. A warm, sheltered spot helps, especially for tall climbers in wind.
- Sow when soil is
- At least 16 °C (60 °F)
- Best growth
- 16 to 24 °C (60 to 75 °F)
- Flowers drop
- Above about 32 °C (90 °F)
Soil
Beans like fertile, well-drained soil rich in organic matter; they don’t do well on heavy clay (Gardeners’ World).
Preparation. Weed, then fork in at least two bucketfuls of garden compost or well-rotted manure per square metre, a few weeks before sowing (RHS).
pH. 5.8 to 6.5 (Clemson).
Warm it. Cover the soil with fleece or cloches for a few weeks before sowing. Utah State plants two to three weeks early under plastic mulch or row covers.
Rotation. Don’t follow beans with beans: diseases carry over in the soil (Illinois).
Planting
Sow once the soil is warm, and put pole supports in before you sow.
Never sow before the soil is at least 16 °C (60 °F): cold, wet seed cracks and rots.
When to sow beans
Sow once frost has passed and the soil has warmed.
Outdoors. In the UK, usually late May or early June (RHS). In the US, around the last frost date, or up to a week or 10 days before it if the soil is already warm (Illinois); in central Iowa, around 10 May.
Indoors. For an earlier crop, sow in deep modules from late April and plant out after the last frost (RHS). Climbers gain most.
Succession. Sow bush beans every two to three weeks until mid-July for a steady supply (UMD, Utah State). Iowa State’s last practical date is 1 August.
Don’t soak the seed. Illinois finds soaked seed cracks and germinates poorly; water after sowing instead.
- After frost, into warm soil.
- Bush beans every 2 to 3 weeks.
- Last sowing around mid-July.
How to sow beans
Beans are sown straight where they grow, or started in modules for a head start.
-
Put supports in first
For pole beans, before sowing, so you don’t damage roots later. See how to plant.
-
Sow at the right depth
About 2.5 cm (1 in) deep (Iowa State, Clemson, Illinois); the RHS sows 5 cm (2 in) deep.
-
Space bush beans
5 to 10 cm (2 to 4 in) apart in rows 45 to 60 cm (18 to 24 in) apart, or 15 cm (6 in) apart in blocks so they hold each other up (RHS).
-
Space pole beans
One or two seeds at the base of each cane, or 10 to 15 cm (4 to 6 in) apart along a trellis; thin to the strongest.
-
Water once
Then keep the soil moist but not soaking until seedlings emerge. Cover with fleece if birds pull them up.
-
Sow spares
A few extra at the end of the row to fill gaps.
Supports and planting out
Pole beans twine up their own supports; they just need something tall and sturdy.
-
Choose a support
A wigwam of four or five canes, an A-frame of paired canes with a crossbar, netting or a trellis, 2 to 2.5 m (7 to 8 ft) tall (RHS, Clemson).
-
Build it strong
Loaded with vines in a summer storm, supports blow over. Push canes well in and tie them firmly.
-
Harden off module-raised plants
Get plants used to outdoor conditions before planting out after the last frost (RHS).
-
Plant one per cane
Or 15 cm (6 in) apart for dwarf beans, disturbing the roots as little as possible.
-
Guide them on
Wind young shoots around their cane; after that they climb by themselves.
Care
Water most when flowering, feed lightly, and keep climbers on their supports.
Beans fix their own nitrogen. Extra nitrogen gives leaves, not pods.
Care by growth stage
Seedlings
Water: moist, not wet
Protect from slugs and birds; weed by hand. See pests.
Growing
Weed: first six weeks matter
Guide climbers onto supports. See supports.
Flowering
Water: 2.5 cm (1 in) a week · Mulch: keeps roots cool
Water well: dry soil now drops flowers. See watering.
Picking
Pick: when dry
Pick every few days to keep plants cropping. See harvesting.
End of season
Rotate: next year
Leave some pods to dry for seed, or clear the plants and rotate. See saving seed.
Watering beans
Beans need steady moisture, and most of all from flowering onwards.
How much. About 2.5 cm (1 in) a week from rain or watering (Iowa State). Water deeply and less often, so the soil is moist 15 cm (6 in) down: light sprinkles make shallow roots (Clemson).
When it matters. During flowering and pod growth. Drought then makes flowers drop and pods small, and stress makes pods stringy (Utah State).
Not too much. Waterlogged soil encourages root rot.
How. In the morning, so leaves dry before night (Clemson). Mulch with compost, straw or grass clippings to hold moisture.
Feeding beans
Beans are legumes: once their roots are established, bacteria in root nodules fix nitrogen from the air. They need little feeding.
Before sowing, compost is usually enough. Without a soil test, Iowa State and Clemson work in a light general fertiliser.
Side-dressing is usually unnecessary (UMD); on sandy soils or after heavy rain, Clemson side-dresses once before flowering.
Too much nitrogen gives lush leaves, delays flowering and cuts the crop (Utah State, UMD).
Inoculant. On ground that hasn’t grown beans before, coating the seed with nitrogen-fixing bacteria can raise yields (UMD).
Supports and training
Beans need no routine pruning, only something to climb or lean on. Once climbing beans reach the top of their support, cut off the extra growth (RHS).
Pole beans twine by themselves once started. Guide young shoots onto the canes, and re-guide any that wander. They won’t weave through horizontal wires, so give them upright canes, poles or netting (UMD).
Bush beans stand alone, but twiggy sticks between plants keep them upright and pods clean (RHS). Sowing in blocks lets them support each other.
Half-runners crop more on a 90 to 120 cm (3 to 4 ft) trellis (Clemson).
Picking reach. An X-frame, with canes crossing at the middle, puts beans within reach and often crops better, but is less sturdy (RHS).
Beans in containers
Dwarf beans grow well in pots, and climbing beans can too with a wigwam.
Dwarf beans. A pot 30 to 45 cm (12 to 18 in) wide, seeds 5 cm (2 in) deep and 15 cm (6 in) apart (RHS).
Climbing beans. A container at least 75 cm (30 in) wide and 45 cm (18 in) deep, heavy enough not to topple, with a cane wigwam, in a sheltered spot (RHS).
Compost. Peat-free multi-purpose or loam-based.
Care. Pots dry fast: water often, especially in flower, and keep them in full sun.
Problems
Cold soil, heat at flowering and a few pests cause most failures.
Common bean problems
Cold soil early and heat or drought at flowering cause many bean failures.
Seed didn’t come up
- Cold soil
- Wet
Soil below 16 °C (60 °F), waterlogged or crusted, or old seed (Utah State). Wait for warm soil, and don’t soak seed.
Flowers but no pods
- Heat
- Drought
Hot weather above about 32 °C (90 °F), dry soil or hot, dry wind drop the flowers. Water and mulch; plants set again as it cools.
Tough, stringy pods
- Stress
- Late picking
Heat or water stress, or pods left too long. Pick young and keep plants watered.
Lots of leaves, few pods
- Too much nitrogen
Overfeeding. Beans make some of their own nitrogen: stop high-nitrogen feeds and follow a soil test.
Plants stop producing
- Mature pods
Pods left to ripen reduce the crop; regular picking keeps plants producing. Pick everything at the right size.
More problems with green beans
Common pests
Slugs and snails
Eat young plants overnight. Raising plants in modules keeps them out of reach until they are sturdier (RHS).
Mexican bean beetle
In the US, copper beetles like large ladybirds with black spots; larvae do the most damage. Look for yellow egg clusters under leaves. Usually minor and worst early in the season; large flowering plants cope with feeding (Illinois, Utah State).
Cutworms and seed maggots
Cut seedlings at soil level, or eat germinating seed in cold soil. Warm soil and weeding help (UMD, Utah State).
Common diseases
Bacterial blight
Yellow or brown leaf spots and water-soaked spots on pods, spread by working among wet plants. Use clean seed, stay out when plants are wet, and clear debris (Illinois).
Bean mosaic virus
Mottled yellow-green leaves and few pods. Grow resistant varieties.
Root rot and damping off
Seedlings darken and die in cool, wet spring soil. Sow into warm soil and don’t overwater.
Rust, grey mould and anthracnose
Leaf and pod diseases in damp weather. Rotate, water at the base in the morning, and choose resistant varieties.
Harvest & Use
Pick pods young, before the beans bulge, every few days.
Harvesting beans
Pick pods young, about 7 to 14 days after the flower (Utah State), and around eight weeks after sowing.
Signs. Pods firm, crisp and full length, about pencil thick and 10 to 15 cm (4 to 6 in) long, with the seeds inside still small (Iowa State). They snap cleanly. If the beans bulge through the pod, it’s past its best.
Pick often. Every few days: pods left to mature slow the plant down. Bush beans crop for two to three weeks, pole beans for five or six weeks or more.
How. Snip or snap the stalk above the cap; stems are brittle, so hold the plant (Illinois). Pick when the plants are dry, in the morning, to avoid spreading blight.
- Young, before the beans bulge.
- Every few days.
- Only when the plants are dry.
Storing and using beans
Beans are best used straight after picking.
Fridge. Unwashed, in a perforated bag in the salad drawer: three days (Illinois) to a week (UMD).
Freezing. Trim, blanch for one to two minutes, cool in iced water, drain and freeze (UMD, Gardeners’ World). Do it within a few hours of picking.
Dry beans. Over-mature pods can be shelled, or left to dry on the plant for haricot beans. Cook dry beans thoroughly: soak for at least five hours, then boil briskly for 10 minutes before simmering (Gardeners’ World).
Cooking. Don’t eat the pods raw (Gardeners’ World): steam or boil them until just tender.
Propagation
Saving seed from your own plants, and when to buy fresh instead.
Saving bean seed
Bean flowers are largely self-pollinated, so varieties rarely cross and saved seed usually comes true (Illinois).
How. Leave a few pods on healthy plants until they are dry and brown. If the weather turns damp, pull the plant and hang it somewhere warm and airy. Shell the beans, let them dry fully, and store them in a jar somewhere cool and dark.
Caution. Bean diseases such as blight and mosaic travel in seed. Save only from clean plants, and Illinois recommends new seed each year to avoid seed-borne diseases.
More to Explore
Quick answers, guides that pair well with beans, and the sources behind this one.
Frequently asked questions
When should I plant green beans?
Usually after the last frost, once the soil is at least 16 °C (60 °F). See when to sow.
Should I soak bean seeds before planting?
No. Illinois finds soaked seed cracks and germinates poorly; water after sowing.
Bush or pole beans?
Bush for speed and small spaces, pole for a longer, bigger crop. See choose your beans.
Why are my bean flowers falling off?
Heat, drought or hot wind. See common problems.
How often should I water beans?
Enough for about 2.5 cm (1 in) a week, most importantly while flowering.
Do beans need fertiliser?
Very little: they fix their own nitrogen, and extra gives leaves instead of pods.
How do I know when beans are ready?
Firm, crisp pods that snap, before the beans bulge. See harvesting.
Can I grow beans in a pot?
Yes: dwarf beans in a 30 to 45 cm (12 to 18 in) pot. See containers.
Can you eat green beans raw?
Gardeners’ World advises against eating the pods raw; cook them.
Related guides
Sources
- How to grow French beans (opens in a new tab) Royal Horticultural Society
- Growing green beans (opens in a new tab) Iowa State University Extension and Outreach
- Growing beans in a home garden (opens in a new tab) University of Maryland Extension
- Beans in the garden (opens in a new tab) Utah State University Extension
- Snap beans (opens in a new tab) University of Illinois Extension
- Bush and pole-type snap beans (opens in a new tab) Clemson Cooperative Extension
- How to grow French beans (opens in a new tab) BBC Gardeners’ World