French beans are delicious and easy to grow in the ground or in containers. The slender, stringless beans make great finger food for children, and come in a range of attractive colours – as well as the usual green, you can grow cream, yellow and purple-podded varieties. There are fast-cropping dwarf varieties, as well as climbing varieties that crop over a longer period – both are ideal in small spaces as they take up little ground space.
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There are two types of French bean – climbing and dwarf. Dwarf beans are perfect for small spaces, growing well in containers and in the ground. Climbing beans need tall, sturdy supports and do best in the ground, but can also be grown in large containers. As they grow vertically, climbers produce a large crop in a small area of ground.
Dwarf beans are quick to grow, but only crop for a few weeks, so make repeat sowings for a summer-long supply. Climbing beans take longer to reach cropping stage, but will produce beans over a longer period, from mid-summer to early autumn if picked regularly.
You’ll find a huge range of varieties available as seed in garden centres and online. There are varieties with pods in a range of attractive colours, from traditional green through shades of yellow and dark purple. Look in particular for varieties with an RHS Award of Garden Merit (AGM), which shows they performed well in trials – see our list of AGM fruit and veg. If you don’t have room to grow from seed, young plants can also be bought from garden centres and online suppliers in spring, ready for planting outside.
For an early crop, sow indoors in late April to early May. Use small pots or modules, sowing one bean in each, 5cm (2in) deep. Place in a propagator or on a warm, sunny windowsill to germinate. They will grow fast in warm, bright conditions and need watering regularly.
In late May or early June, harden off the young plants to acclimatise them to outdoor conditions. Then plant into their final site, either in the ground or in a large container, after all risk of frost has passed – see Plant outside, below.
Sow outdoors – in the ground
French beans can be sown outdoors once all risk of frost has passed and the soil is warming up. This is usually in late May or early June, depending on your local climate. You can warm the soil with fleece or cloches before sowing, then leave the covering in place after sowing to give the young plants extra protection.
If growing in the ground, choose a warm, sunny spot, then prepare the site by removing weeds and forking in plenty of well-rotted manure or garden compost, and watering well.
With climbing beans, it’s best to put the supports in place before sowing – these are usually tall bamboo canes, in a wigwam or double row – see Grow, below, for details.
Dwarf beans are best sown in blocks rather than rows, so they support each other.
Sow the seeds individually, 5cm (2in) deep and 15cm (6in) apart. With dwarf beans, you can make several sowings of small batches a few weeks apart, to provide harvests over a longer period.
Sow outdoors – in containers
You can sow seeds outdoors into pots of multi-purpose compost in spring – either into small pots for transplanting into the ground later, or into large containers as their final growing site. Sow one bean per small pot, 5cm (2in) deep, and place in a coldframe or a warm, sheltered position. The seedlings may need some protection (such as fleece) at night. Once the plants reach 8cm (3in) tall and all risk of frost has passed, plant out into their final positions (see Plant outside, below).
Both dwarf and climbing beans can be grown in large containers and make attractive additions to patios and small gardens. They need a warm, sheltered, sunny position. For dwarf beans the container should be 30–45cm (12–18in) wide, and for climbing beans 75cm (30in) wide and 45cm (18in) deep – a large tub or half-barrel is ideal.
Simply sow the seeds direct into the container, spacing them 15cm (6in) apart. Insert a wigwam of 1.8m (6ft) canes to support climbing beans (see Grow below), and choose a heavy container to keep it from toppling over. Dwarf beans don’t usually need support and look great cascading over the sides of a pot, or even in a hanging basket.
Wait until after the last frost before planting indoor-raised or bought young plants outside. Then harden them off to acclimatise them to outdoor conditions for a couple of weeks, either by putting them in a coldframe or placing them in a warm, sheltered spot, covered with fleece. Once hardened off, plant them into their final growing position, in a sunny, sheltered spot. If planting in the ground, enrich the soil with well-rotted manure or garden compost beforehand. If planting in a container, choose multi-purpose or loam-based compost. Containers should be at least 30–45cm (12–18in) wide for dwarf beans, and 75cm (30in) wide and 45cm (18in) deep for climbing beans.
Water plants well before and after planting, and space them 15cm (6in) apart.
With climbing beans, it’s best to put the supports in place first – see Grow, below. Position one plant at the base of each cane, and loosely tie the shoots to the cane to get them started.
Supporting French beans
Climbing French beans need tall, sturdy supports to climb up. The traditional method is to grow them along a double row of bamboo canes (1.8m/6ft tall), with 45cm (18in) between the two rows. Space the bamboo canes 15cm (6in) apart within each row and slope them inwards, then tie near the top to a horizontal cane, to form an A-frame.
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 to link them all together and increase stability. An X-frame takes up more space, but picking is easier and cropping is usually better.
If you don’t have room for a double row of canes, you can make wigwams. Again, use 1.8m (6ft) canes, four or five per wigwam, spacing them 15cm (6in) apart at the base. Tie the tops of the canes together. Wigwams make an attractive feature in a border or veg plot and also work
well when growing in containers. Loosely tie young plants to the canes to get them started.
With dwarf beans, you can insert short twiggy sticks between the plants to keep them upright and lift the pods off the soil.
Beans are thirsty plants and crop best when watered regularly, especially once they start to flower and form pods. Regular and generous watering is particularly important for plants growing in containers, which dry out quickly.Mulching
Place a mulch of well-rotted manure or mushroom compost around plants in July to help hold moisture in the soil.
Keep plants weed-free. Growing plants through slits in weed-suppressing membrane is possible, and prevents the pods of dwarf beans being damaged by contact with the soil.
You can harvest French beans from mid-summer to early autumn. If picked regularly, dwarf French bean plants will crop for several weeks and climbing French beans for much longer.
Begin picking the pods when they’re 10cm (4in) long. They are ready when they snap easily and before the beans can be seen through the pod.
French beans — climbing
French beans — dwarf
Slugs and snails
These feed on the young seedlings and you'll see the tell tale slime trail on the soil around your crop, as well as on the leaves.
There are many ways to control slugs and snails, including beer traps, sawdust or eggshell barriers, copper tape and biocontrols.
Birds, especially pigeons, can cause an array of problems including eating seedlings, buds, leaves, fruit and vegetables.
Protect the plants from birds by covering them with netting or fleece. Scarecrows and bird-scaring mechanisms work for a while, but the most reliable method of protection is to cover plants with horticultural fleece or mesh.
Black bean aphid
Sap-sucking aphids will disfigure plants and cause stunting to leaves and stems.
In the case of broad beans, pinch out infested tips. On other beans, catch populations when small and squash.
Try this simple summer salad of French beans atop mozzarella slices with an unusual yoghurt dressing.
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