RHS Growing Guides
How to grow runner beans
Our detailed growing guide will help you with each step in successfully growing Runner beans.
Getting Started
Runner beans are a veg plot staple – one of the easiest crops to grow, producing an abundance of long green pods from mid-summer to early autumn.
Harvest runner beans regularly to keep plants flowering and producing more pods
For a good crop, give runner beans sun, rich soil and plenty of water – they particularly thrive in cool, wet summers. Pick the pods regularly when young, tender and stringless, to keep them coming through summer and into autumn.
Month by Month
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Choosing
Different runner bean varieties offer various flower colours, pod sizes, flavours and textures
There are many varieties to choose from, with different pod sizes and flower colours (red, white, pink or salmon). Varieties with some French bean parentage, such as ‘Firelight’ and ‘Moonlight’, are a good choice in regions that get hot summers. For overall reliability, look for varieties with an RHS Award of Garden Merit (AGM), as these performed well in our trials – see our list of AGM fruit and veg and our Recommended Varieties below. You’ll also find an array of different beans growing in the veg areas of the RHS gardens over the summer months, so do visit to compare varieties and pick up growing tips.
What & where to buy
You can buy a wide choice of runner bean seeds in garden centres and from online retailers. Many also sell young plants in spring and early summer – ideal if you only want to grow a few or don’t have space indoors to grow them from seed yourself.
Recommended Varieties
Preparing the Ground
Choose a sunny, sheltered position for runner beans. Weed the ground thoroughly, then fork in lots of home-made garden compost or well-rotted manure – at least two bucketfuls per square metre/yard. Ideally do this a few weeks before sowing or planting out, to allow time for the ground to settle. Alternatively, if you're practising no-dig, mulch the ground ahead of sowing or planting directly into the mulch.
Putting up supports
Why not make a feature of your runner beans by building a tunnel support over a path?
Alternatively, create an X-frame by sloping the canes at a sharper angle so they cross in the middle. Tie them at the centre, and add a horizontal cane at this point to link them all together and increase stability. An X-frame makes picking easier as the beans are within reach and cropping is usually better, but it can be less stable.
If you don’t have room for a double row of canes, you can make a wigwam. Again, use 2.5m (8ft) canes or hazel poles, five or more per wigwam, spacing them 15–30cm (6–12in) apart at the base, then tie the tops together. Wigwams make an attractive feature in a border or patio container, as well as on the veg plot. You can also get creative and construct arches over a pathway, or grow your runner beans up netting, trellis or other tall structures.
With dwarf beans, insert short twiggy sticks between the plants to keep them upright and lift the pods off the soil.
Sowing
Runner beans won’t survive frost, so for an early crop sow seeds indoors in late spring. Indoor sowing is also best in colder locations, to provide a longer growing season. Seeds can be sown outdoors too, from late spring to mid-summer.
Sowing indoors
From mid-April to May, start runner beans off indoors, on a sunny windowsill or in a propagator or greenhouse. This will give you an earlier crop than sowing outdoors, as well as more reliable germination, and the seedlings will be protected from slugs and snails. Use small pots or trays of deep modules and fill with moist peat-free multi-purpose compost. Sow one bean into the centre of each, 5cm (2in) deep, and water well. Keep in a warm, bright place at over 12°C (54°F). For more sowing tips, see our guides below.
Runner bean seedlings grow rapidly and need watering regularly. Young plants can be moved outside once all risk of frost has passed, usually in late May or early June – see Planting, below.
Sowing outdoors
Runner bean seeds need warm conditions to germinate, so wait until all risk of frost has passed and your soil has reached 12°C (54°F) – usually by mid-May in the south of the UK and early June in the north. Seeds can be sown in the ground or in containers.
Sowing in the ground
Sow seeds individually 5cm (2in) deep – two at the base of each bamboo cane. Once they germinate, thin to one seedling per cane, and protect from slugs and snails. With dwarf runner beans, allow 30cm (1ft) between plants and 50cm (20in) between rows.
Sowing in containers
You can sow runner beans either into small pots for transplanting into the ground later, or into large containers as their final growing site. Use peat-free multi-purpose compost. Sow one bean per small pot, 5cm (2in) deep, and place in a coldframe or sheltered spot. Once the plants reach 8cm (3in) tall, in June or July, plant them into their final positions – see Planting, below.
Alternatively, sow into a large container as their final growing site. For dwarf runner beans the container should be 30–45cm (12–18in) wide, and for climbing varieties 75cm (30in) wide, 45cm (18in) deep and heavy enough to keep it from toppling over once the beans are growing strongly up their supports. Insert a wigwam of 2.5m (8ft) canes for climbing varieties (see Putting up supports, above). Sow the seeds 5cm (2in) deep and 15cm (6in) apart. With climbing beans, it’s best to sow two seeds at the base of each cane, to allow for losses, then if both germinate simply remove the weaker/smaller one.
Planting
Keep runner beans indoors until after the last frost, then plant in a warm, sunny spot
With dwarf runner beans, space plants 30cm (1ft) apart and consider planting through plastic-free weed-suppressing membrane as this reduces the need for weeding and prevents pods being damaged from contact with the soil. Protect plants from slugs and snails.
If planting in a container, choose peat-free multi-purpose or loam-based compost. Containers should be at least 75cm (30in) wide and 45cm (18in) deep for climbing varieties, and 30–45cm (12–18in) wide for dwarf beans.
Plant Care
Watering
Runner beans are thirsty plants and crop best when their roots have plenty of moisture, so regular watering is usually required, especially once they start to flower and form pods. When growing beans in containers, frequent and generous watering is particularly important as they will dry out quickly. For water-saving tips, see our guides below.
Mulching
Spread a mulch of garden compost or well-rotted manure around your bean plants after planting to help hold moisture in the soil and deter weed germination.
Feeding
Runner beans are vigorous, productive plants that don’t usually need feeding when growing in the ground. However, when grown in containers, feed every fortnight with a high potassium organic liquid fertiliser, such as tomato feed, once the first flowers appear.
Pruning and Training
Tie in any stems that come loose from their supports. Once climbing varieties reach the top of their supports, cut off any extra growth. This should encourage side-shoots lower down, keeping the crop within reach and helping to stop plants becoming top-heavy.
Harvesting
Pick runner beans regularly, so you can enjoy them when young and tender, without any stringiness
Once harvesting has finished, cut plants down to the base and compost them. However, as legumes (peas, beans and related plants) fix nitrogen from the air at their roots, leave these in the ground to boost soil nitrogen levels.
Problems
Runner beans are one of the easiest vegetables to grow, but they must be kept indoors until after the last frost. Young plants are vulnerable to slugs and snails, and black aphids can cause problems if they get established.
These large, vigorous plants also need plenty of moisture to crop well, so water regularly, especially in dry spells. Hot weather can also hinder cropping. Occasionally, fungal or bacterial diseases such as rust or halo blight can develop, and in warm, dry conditions red spider mites can cause problems.
For more on spotting and tackling these issues, see Common problems, below.
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