Bean feast!

Climbing, dwarf or runner, knowing how to plant beans – and what to plant them with – is the secret to a bumper harvest, says Monty Don

Why do we call French beans ‘ French’? I have not been able to establish the reason. In fact, Phaseolus vulgaris come from Central and South America, where they were often grown as part of the ‘ three sisters’ combination of crops. Squashes would be planted first at fairly wide spacing, then maize or sweetcorn interplanted among them. Finally beans would be placed in the remaining gaps, and they’d use the stems of the corn for support as they climbed. As well as being an economical use of precious cultivated ground, the beans – being legumes – took nitrogen from the air and left it as a deposit in the soil, which the corn and squashes could use for nourishment. It is still a very good way of growing the three crops in the limited space of a small garden.

Another useful combination is cabbages grown with dwarf beans, which results in the cabbages being less likely to be attacked by cabbage root fly. This is because the fly lays its eggs – from which destructive maggots emerge – after it has landed on several cabbage plants in succession. By breaking that succession with the interspersal of beans, the fly will move off and not lay.

Climbers were the first of these beans to be introduced to Europe, in the late 15th century, though we know dwarf varieties were being grown in Britain around 100 years after that. Runner beans came along some 50 years later and one of these early varieties, ‘Painted Lady’, is still being grown in our gardens and allotments. We think of the runner bean, Phaseolus coc

cineus, as a very British vegetable but it also comes from Central and South America, where it grows as a perennial. It occurs naturally at an altitude of around 2,000m (6,500ft) in Central America, preferring the north-facing, more shady side of the hill. It doesn’t like blazing sunshine and copes well with our cool, damp summers. If you do grow it in open ground, in full sun, it’ll need lots of moisture, especially during dry summer spells, and lots of organic matter, such as compost or well-rotted manure, dug into the soil before planting to hold that water so the roots can get at it before it drains away.

While we think of dwarf beans as being eaten for their seemingly beanless pods, all bean pods exist for the seed or beans to grow within. To eat a bean – either as a pod or when the bean is green (technically a flageolet, whereas the dried bean is a haricot) – before the seeds ripen is a great luxury; historically, the beans, once dried, were too useful a winter food to be eaten, indulgently, as a summer dish of unripened pods. Runner beans in particular become tough and stringy if allowed to grow too large, so pick them before they’re fully grown – so about 15cm-20cm (6in-8in) long – while the seeds are still small and pale in colour. They should snap off easily when ready.

Although you can order bean seeds this autumn, you’ll now need to wait until next spring to sow them. All these beans – climbing, dwarf and runner – need a soil temperature of over 12ºC to germinate, and even if they did start to grow before the spring, a cold spell would mean weak growth, and the plants would become a magnet for slugs. If planting directly, I sow in double rows 23cm (9in) apart, with 46cm (18in) between each double row, and about 10cm (4in) between each bean. If I’m planting out indoorraised seedlings, I do so in blocks, with 23cm (9in) between each plant.

Over the years I’ve grown a pretty wide selection of beans but keep coming back to yellow and purple varieties such as ‘Golden Sands’, ‘Annabel’ and ‘Blauhilde’. Purple dwarf beans are able to withstand colder weather than most other types so are good for a late sowing that will crop well into autumn.

Monty with his ‘Blauhilde’ beans