How To Grow Runner Beans

Runner beans are relatively simple vegetable seeds to grow, making them an ideal addition to many gardens. For example, dwarf varieties, such as Hestia, don't require support, making them perfect for growing in patio containers. Unbelievably, some people don't like runner beans, the usual reason being that shop-bought runners can be tough and stringy. If you’ve been of this opinion, growing your own and picking them just when they're ready will show you what you've been missing. Also, you can choose stringless varieties, such as Moonlight and Firestorm, which are even more succulent.

If you’re looking to grow runner beans within your growing space, take a look at our comprehensive guide, where we cover how to do so with step-by-step advice for a bountiful harvest. For advice on growing more varieties of bean plants, read our guides on how to grow broad beans and how to grow French beans to get you started.

Runner beans should be grown in a spot with plenty of sunlight, and do best in well-drained, fertile soil. To avoid competition, you should also dig the area thoroughly to remove weeds.

You should add plenty of well-rotted compost or manure to your plot to ensure your plants have the nutrients they need for vigorous growth. However, this should be done a few weeks ahead of growing your runner bean plants, as soil that is fertilised shortly before planting will lead to more foliage growth as opposed to bean growth.

If you’re wondering when to sow runner beans, you should do so from late May to the end of June, as this is when the last frost will occur. You should sow runner bean seeds 2in (5cm) deep and 9in (23cm) apart. It’s recommended to sow two seeds rather than one in case one fails to germinate, then thin out to leave the strongest seedling.

The traditional method of growing is to sow a double row with the two rows 18in (45cm) apart; this makes supporting the plants easier.

Alternatively, for an earlier crop, sow the beans in 4in (10cm) pots at the end of April indoors, in an area with a good amount of light. Seeds will germinate and grow very quickly in around one week, so ensure they are regularly watered during this time.

When plants are at least 4in (10cm) tall with a minimum of two leaves, harden them off for about 7 to 10 days, gradually exposing them to outdoor conditions. Once acclimatised, they can be planted out, 9in (23cm) apart, if there is no risk of frost. Be sure not to keep them in their pots for too long, however, as their stems and vines can become tangled with neighbouring plants.

Support

Runner beans need a support to climb up. The traditional method is to grow them individually up inwardly sloping 8ft (2.4m) bamboo canes, tied near their top to a horizontal cane. If you angle the bamboo canes so that they meet and are tied together at the top, with the ends of the canes extending beyond the row, it will make picking the beans easier and usually result in a better yield.

When growing in beds and borders, a pea and bean wigwam of canes takes up less room and helps produce an ornamental feature. Loosely tie the plants to their supports after planting; after that they will climb naturally. Remove the growing point once the plants reach the top of their support.

Growing in Pots

If you’re limited on space, you can grow runner beans in seed pots. Runner bean plants will grow just as vigorously in pots as they do in plots, so are an ideal choice for smaller growing areas. There are several options for dwarf bean plants for runner beans that especially lend themselves to being grown this way.

The pot should be large enough to provide enough support and stability for the plants. For dwarf runner bean plants, this is 12-18in (30–45cm) wide. Climbing runner beans will need a pot 30in (75 m) wide and 18 in (45cm) deep, with a wigwam of 8ft (2.4m) canes inserted for support. 

Sow the seeds 2in (5cm) deep and 6in (15cm) apart into compost in their pots. Sow two seeds at the bottom of each cane and thin out to leave the strongest seedling.

Watering

Runner beans are thirsty plants, so it’s vital that you keep them well-watered and do so regularly—especially when your plants are flowering. Runner beans grown in pots are more prone to drying out, so this is especially important if you are growing your beans this way. 

Feeding

A liquid feed, applied once every fortnight, can be highly beneficial for your runner bean plants. We recommend using our Plant Tonic No. 8, formulated with seaweed, yucca, and chitosan, to maintain their strong and healthy growth.

Mulching

Adding a layer of mulch around the roots can help your plants to retain moisture, so we recommend adding a layer of organic matter, such as compost or manure, during June and July. This is when runner beans grow the most and will need to keep moisture as a result.

Weeding

Ensure that you keep your plot weed-free so your bean plants grow to their full potential. Using weed control products, such as weed membrane or 25cm weed control coir mats, can help to supress weed growth. However, hand-weeding or using a weed cutter is always an effective solution.

As mentioned above, runner beans have a reputation for being stringy, though this is easily prevented by picking your runner beans at the correct time. So, when is the best time to harvest runner beans?

Start harvesting when the pods are at their most tender, at 6-8in (15-20cm) long, and certainly before the beans inside begin to swell. This is usually in July. It is vital that you pick regularly to prevent any pods reaching maturity. Once this happens, plants will stop flowering, and no more pods will be set. If you pick regularly, your plants will crop for up to eight weeks. To store your runner beans for extended periods, they are suitable for freezing.

As easy-to-grow vegetables, runner bean plants generally don’t pose too many problems while growing. However, there are one or two possible issues that you can learn how to prevent or treat below:

• Pests - Keep an eye out for slugs, snail and blackfly that may attack the plants. You can resolve these pest problems with our garden pest control products. Sowing in pots is also a good deterrent for slugs and snails.
• Rust - Runner bean rust is a fungal infection, which can be recognised by dark brown pustules on the underside of leaves. To prevent this, avoid watering the leaves of your plant as this occurs in moist, warm conditions. Any leaves that have been infected with rust should be removed and disposed of.

Flower Set

Runner beans sometimes fail to set and produce beans. There are a number of causes for this and solutions to prevent this from happening to your plants:

• Ensuring the soil is constantly moist and doesn't dry out is the first key to success, so you should mulch the soil in June.
• Misting the foliage and flowers regularly, especially during hot, dry weather, will increase humidity around the flowers and help improve flower set.
• Flower set is better in alkaline, chalky soils. If your soil is neutral or acidic, it pays to water with hydrated lime.
• Another way to improve flower set is to pinch out the growing tips of the plants when they are 6in (15cm) high. The flowers formed on the side shoots usually set better.

Now that you’re fully in the know on how to grow runner beans, you can get started by shopping our quality seeds at D.T. Brown. With over a century of expertise, you can rely on our runner bean seeds and runner bean plants to provide you with a great yield. If you’re eager to grow even more produce, you can find more expert growing guides and gardening tips on our gardening blog to fill your garden with plenty of flavoursome produce.

If you’d like to find out more about our range of vegetable seeds, vegetable plants, fruit seeds, and flower seeds, don’t hesitate to get in touch and we’ll happily answer any questions you may have.