How to Grow French Beans

French beans should be grown in a spot with plenty of sun and moisture-retentive soil that’s been weeded before sowing or planting. Add in plenty of well-rotted manure or garden compost before planting to improve the soil’s moisture retention, break up compacted soil and provide beneficial nutrients. This is best done a few weeks in advance if possible to allow time for the soil to settle.

When to Sow French Beans

French beans can be sown either indoors or outdoors. If sowing indoors, you should start doing so between April and May. Sowing your beans indoors means that they will typically crop earlier due to being given a head start. 

Sowing outdoors is generally more straightforward, though you will need to wait until May or June to do so. If you wish, you can sow them in early July to extend the season into September or October.

How to Sow French Beans

Sowing French Beans Indoors

To start French beans earlier indoors, sow seeds 2in (5cm) deep in seed trays or small pots and use a garden propagator or place on a warm, south-facing windowsill to aid germination. Maintaining warmth, exposure to sun and regular watering are all key to their success.

Harden off your plants in late May or early June for a few weeks before planting outside, either in a cold frame or in a warm spot covered in fleece for plants. French beans are especially sensitive to cold temperatures, so this step is key. After the last frost, you can plant them outdoors. 

Sowing French Beans Outdoors in the Ground

As stated above, you should sow your French beans after the last frost has occurred in late May or early June. A few weeks prior to planting, warming up the soil using fleece for plants or garden cloches can help to improve germination. These can also be used for protection if a sudden cold snap is predicted overnight.

Sow French bean seeds outdoors 2in (5cm) deep, in (10cm) apart, in rows 18in (45cm) apart, with one or two seeds sown at the base of a cane. Sow a few extra seeds at the end of the rows to fill in any gaps where seeds don't germinate. Thin out to leave the strongest seedling if necessary.

Bush French beans can be sown in double rows or blocks so that the plants can support one another. 

Sowing French Beans Outdoors in Containers

French bean seeds can be sown in containers in quality garden compost outdoors, both in smaller containers to be transplanted in the ground or in large containers as their final growing place.

If you choose to do the former, sow one seed per small pot 2in (5cm) deep and move the pot to a cold frame. Alternatively, you can move it to a warm and sunny position, ensuring it is protected with shelter and fleece for plants. The plants will be ready for transplanting to their final site after the last frost and when the plants are at least 3in (8cm) tall.

For growing in pots as their final growing site, they should be grown in a warm, sunny spot with some shelter. Bush French beans will need a pot around 12–18in (30–45cm) wide. Climbing French beans will need to be grown in a heavy pot that won’t topple over when the plants reach their maximum height. This should be at least 30in (75cm) wide and 18in (45cm) deep.

Add a wigwam of 8ft (2.5m) canes into your container prior to sowing. Bush varieties won’t need support. Afterwards, sow your seeds 2in (5cm) deep and 4in (10cm) apart, with one or two at the base of each cane. If necessary, thin out the seedlings to leave the strongest one.

Support

Supporting Climbing French Beans

Climbing French beans will need a support to twine up as they grow. The traditional method is to grow them 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; they will climb naturally after that.

Another option for support is to use pea and bean netting. Securely place two strong stakes into the soil standing 6ft 6in (2m) above the ground and run heavy-duty wire across the tops of them. Then, attach the net to the wire and stakes with garden twine and secure it to the ground with netting pegs.

Remove the growing point once the plants reach the top of their support, as this will help side shoots to develop lower down the plant. Any shoots that become loose from canes should be tied in.

Supporting Bush French Beans

Bush French beans generally won’t need support, though using short twigs can help to keep your plants upright and the beans off the soil.

When to Plant French Beans

French beans should be planted outside after the last frost, which is generally around late May, though it varies depending on your location. This ensures that frost doesn’t affect your plants, as they are susceptible to it.

How to Plant French Beans

For transplanting into large containers, Bush French beans will need a container around 12–18in (30–45cm) wide, while climbing French beans will need one that’s 30in (75cm) wide and 18in (45cm) deep.

For container and ground growing, space your French bean plants 6in (15cm) apart and water well before and after planting. Loosely tie the shoots of climbing varieties to their support to help on their first step of climbing.

Watering

French beans are thirsty plants, so will need regular, generous watering. This is especially the case with plants grown in pots, as these can dry out quicker than plants grown in the ground.

Mulching

You should mulch organic matter, such as well-rotted manure or garden compost, around your French beans. This will keep the soil moist, provide beneficial nutrients and prevent the development of weeds. Mulch your plants in June to effectively maintain moisture when the soil is warm and your plants are most at risk of drying out.

Weeding

Keep the soil free of weeds to prevent competition for nutrients from other plants. Mulch, as mentioned above, or weed control products, such as weed coir mats, are useful methods.

When to Harvest French Beans

French beans will be ready to harvest from July through to mid-autumn. You should begin picking the pods when they are 4in (10cm) long.

How to Harvest French Beans

Pods are ready for harvest when they snap easily and before the beans can be seen through the pod. By picking regularly, you can crop plants for up to seven weeks. You should make an effort to do so, as energy will otherwise be redirected into producing seeds. If you don’t wish to use any more beans, you can blanch beans in boiling water for two minutes and keep them in your freezer.

Once all the pods have been harvested, water the plants and feed them with liquid fertiliser. This way, you can get a second cropping of smaller yet worthwhile pods.

French beans are generally trouble-free, though there are a couple of problems they are susceptible to experiencing. Below are the most common problems that French beans experience and how to prevent or resolve them:

• Frost: French beans are particularly susceptible to frost, so should not be grown outdoors until the last frost occurs. If a sudden cold snap is predicted, cover your French beans with fleece for plants or garden cloches.
• Slugs and snails: Slugs and snails can attack seedlings and younger plants, so use slug and snail control products to prevent or deal with the problem.
• Blackfly: Blackfly can affect your French bean plants by sucking sap and damaging leaves. These can be squashed by hand or controlled using pest and disease control products.

If you’re eager to grow your own French beans to enrich your home cooking, we have an excellent selection of French bean seeds and French bean plants to get you started. With a wide range of different cultivars to choose from, you can choose from many French beans that offer vastly superior flavours to shop-bought varieties.

For learning how to grow many more varieties of vegetable seeds and fruit seeds, our garden blog has many more growing guides containing expert advice to get your garden flourishing with an array of delicious crops.

To learn more about our selection of herb seeds, flower seeds, garden equipment, or any other items in our collection, get in touch with us today and a member of our team will gladly help you out.