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French Beans

Phaseolus vulgaris

INTRODUCTION

French Beans, sometimes called green beans, come in two distinct forms; dwarf and climbing. The climbing form is a good alternative to Runner Beans and is available in purple and yellow variations.

These beans, originating from South America and first introduced to Europe in the 16th century, are high in protein and a useful source of potassium. If short on space, French Beans are ideal for growing in containers and, being self-pollinating, can produce in the greenhouse or polytunnel much earlier than outdoor crops.

Soil Preparation

The site should be sunny, sheltered and away from prevailing winds.

For the very best crops, the soil should be deeply cultivated, rich, fertile and moisture retentive.

Add plenty of well-rotted organic material in the autumn before planting.

If the growing site is exposed, consider growing dwarf varieties only.

Prepare the seedbed by removing any weed from the soil and rake level to a fine tilth.

Sowing & Planting

French Beans are frost-sensitive and sowing should not be made until all risk of frost has passed.

Soil temperatures need to be at least 12oc. Cover soil with fleece or cloches ahead of sowing to warm it up.

Sowings should be at a depth of 5cm (2 inches) with seed spaced at approx 8cm (3inches). Leave 25cm (10 inches) between rows.

Sow every 3-4 weeks to ensure a continuous supply throughout the summer.

As an alternative to direct sowing, sow one or two seeds into a 10cm pot filled with multi-purpose compost and keep in the greenhouse or polytunnel. Plant out at similar spacings to direct-sown crops as soon as large enough to handle.

If you are short on space, French Beans make a really good vegetable to grow in pots and other containers. We find a container of at least 10 litres is suitable with about 10 seeds sown directly into it. You can start it undercover, moving it outside when conditions permit.

This is a particularly useful growing system for early and extra late harvests.

Growing & General Cultivation

Keep growing crops weed-free.

Keep well-watered during dry weather and while flowers and beans are starting to set.

Climbing French Beans will require some form of support.

You can use support methods as you would for Runner Beans or as an alternative, set up 4 or 5 canes into a 'wigwam' formation.

Pests & Diseases

French Beans are usually trouble-free but may succumb to similar issues as you would find for Runner Beans.

Mice may dig up directly sown seed. If this is a problem, raise plants in pots.

Slugs and Snails can be a problem for young plants in the early stages of growth, especially with direct sown crops. For remedies - see Product Directory.

Black Bean Aphid feeds on plant sap and can be unsightly. Spray with an organic pesticide - see Product Directory.

Halo Blight is spread by water and appears as yellowing on the foliage which if left will die off. Severe outbreaks will result in reduced harvests. Remove affected foliage as soon as the problem shows up.

Root Rot can occur if plants are trying to establish in poorly drained soils. Soil should be moisture-retentive but well-drained.

Red Spider Mite shows up as yellow mottling on the foliage. On the underside of leaves, webbing will become obvious in severe cases, with mites clearly visible. The pest is normally more of an issue on indoor crops, particularly during hot, dry weather. Biological control is available. See Product Directory for details.

Harvesting

Crops will be ready to harvest after about 10 weeks.

Carefully detach beans from plants taking care not to damage remaining growth.

Harvest before beans become old and stringy.

Crop regularly to encourage further flower/bean formation. Plants should continue to crop for 3-4 weeks.

Old beans can be left on the plants to dry out and be used for home-saved seed, but if growing more than one variety, cross-pollination may occur and varieties may not come true.

French Beans are always at their best when consumed immediately, however, excess harvests make an excellent candidate for the freezer.