Dwarf bean

Origin & history

The common bean comes from Central and South America, where it was domesticated twice independently — in Mexico and in the Andes. After 1500 it displaced Europe’s older pulses so thoroughly that the word “Bohne”, which until then meant the broad bean, transferred to it. Stringless varieties, which we take for granted, only appeared in the late 19th century; before that every pod had to have its string pulled off.

Varieties

The distinction is in the pod: filet and fine beans stay slim and tender, while snap types grow fleshier and crop more heavily. Besides green there are yellow wax beans and purple-podded varieties that turn green on cooking — both are far easier to spot among the foliage when picking than green ones. Dwarf beans are self-pollinating and nearly all open-pollinated: let a few pods ripen and next year’s seed is taken care of.

Care

Beans supply their own nitrogen through root nodule bacteria — feed them and you get plenty of leaf and few pods. Once the plants are a hand high, earth them up lightly; that steadies them and gives extra roots. From flowering on water evenly and always at the base, never over the foliage, and stay out of the rows while the plants are wet.

What can go wrong

Wet foliage is the real problem: anthracnose and halo blight spread from plant to plant as you walk the rows, so pick only once the crop has dried off, keep the rows wide and never save seed from affected plants. If whole stretches of the row stay empty, the soil was too cold and wet at sowing — below 10 °C the seed simply rots. Slugs clear fresh seedlings overnight; collect them in the evening or raise the first sowings in pots and plant them out larger.

Harvest, storage & kitchen

Go through every two or three days — pods left to ripen slow down new set, and one overlooked row ends the harvest early. The moment is right when the pod snaps cleanly and the seeds are not yet showing through. Beans are never eaten raw: the phasin they contain is only destroyed by at least ten minutes of boiling; for the freezer, blanch them briefly and plunge them into cold water.

Frequently asked questions

When do you sow dwarf beans outdoors?

From mid-May until about 10 July, sown straight into the bed. Set the seeds around 3 cm deep, 10 cm apart in the row and 40 cm between rows. Before mid-May the risk of late night frosts is too high, and in cold soil little will germinate anyway.

When are dwarf beans ready to pick?

Roughly eight to ten weeks after sowing, which on the calendar means early July to early October. A single row keeps cropping for about two to three weeks, after which the set drops off noticeably.

Why are my dwarf beans flowering but not setting pods?

Heat and drought are the usual cause: above about 30 °C, and in dry soil, the flowers drop before a pod can form. Once it cools down and the soil stays evenly moist, plants normally start setting again. A lack of insects is not the reason — beans pollinate themselves.

Are dwarf beans winter hardy?

No, not in the slightest — the first light night frost finishes the crop, which is why harvest runs out in early October. Dwarf beans are annuals and are sown afresh every spring; the only thing that overwinters is the seed, kept cool and dry.