How to Grow Broad Beans from Seed (Vicia faba): Sowing, Care & Harvest

Of all the crops in the vegetable garden, broad beans are the one that most rewards a decision made in September. Sow now — or in the next eight weeks — and you can be picking in late May, three weeks before anyone who waited for spring. Sow in February instead and you will still get a fine crop, with far less risk. The interesting thing is that both answers are correct, and which one is right depends less on your enthusiasm than on your soil, your winter and the variety in the packet. Vicia faba is also, botanically, not a bean at all, and that single fact explains almost everything it does.

• Sow Late Oct–Nov (hardy types, free-draining soil) · Jan under glass · Feb–May outdoors
• Depth & space 5 cm deep · 20 cm apart in double rows 20 cm apart · 60–80 cm between rows
• Height 80–120 cm for most varieties · always needs string and canes
• Harvest Late May–Aug · whole pods at 6 cm, shelled beans at 15 cm+

Broad beans are vetches, not beans

Vicia faba sits in the genus Vicia — the vetches — alongside the field beans and tares that farmers have grown as fodder and green manure for centuries. French and runner beans belong to Phaseolus, a completely different, New World genus that will not tolerate a degree of frost. That is why broad beans can be sown into cold, wet November soil and French beans cannot, and it is also why the plant behaves so unlike anything else in the legume collection: upright rather than climbing, tolerant of heavy ground, and quite happy at 5 °C when most seeds are still dormant.

The seed itself is the largest of any common vegetable — which has two practical consequences. It carries enough stored food to push up through 5 cm of soil, so you never need a fine tilth. And it is a magnet for mice, who will take a whole row from a November sowing and leave the ground looking untouched.

When to sow: the autumn question, answered honestly

Autumn sowing is the trick every gardening book mentions and rather fewer books qualify. Sown in late October or November, a broad bean germinates slowly, makes 8–10 cm of top growth and a surprisingly deep root, then sits out the winter. Come March it grows away from an established root system and crops two to three weeks earlier than a February sowing — early enough to be picked before blackfly arrive in numbers.

What the books tend to leave out is the failure rate. Autumn sowing pays on free-draining soil in a mild, sheltered garden, with a variety bred for the job — the hardy longpod types. On cold, heavy, wet ground it is a lottery: the losses come from waterlogging and mice far more often than from frost, and a wet winter also invites chocolate spot. Most of the varieties in our broad bean range — Witkiem, Meteor, Major, Leidse Hangers and Threefold White — are early types whose packets recommend sowing under glass in January or direct from February to May. That is deliberately the more reliable route, and for the majority of gardens it is the one we would suggest. Browse them by species under Vicia faba, or the organic selection in organic broad beans.

How to sow broad beans, step by step

1. Do not enrich the bed Broad beans fix their own nitrogen. Well-worked ground with a little garden compost is plenty — see preparing your soil. Rich soil gives soft, leafy, blackfly-prone plants.
2. Sow 5 cm deep in double rows Two staggered lines 20 cm apart, seeds 20 cm apart within them, then 60–80 cm to the next pair. Double rows support each other, which halves the staking work. See direct sowing.
3. Or start in deep modules if mice are a problem Root trainers, a cold frame, plant out at 8–10 cm. This is the standard workaround for autumn sowing and it also beats slugs on heavy ground.
4. Do not water after sowing Autumn and early spring soil holds more than enough. A large seed in cold, saturated ground rots before it germinates — this is the single commonest cause of a failed row.
5. Put the supports in before you need them Canes at each corner with string at 30 cm and 60 cm, added in early spring. Once a flowering plant goes over in wind it snaps at the base — see plant supports and trellising.

Autumn sowing vs spring sowing

There is no reason to choose only one. A short autumn row as an experiment plus a February sowing as insurance is how most experienced growers handle it, and repeat sowings every three weeks until May stretch the harvest into August — the same principle as succession sowing. If autumn sowing appeals for other crops too, our guide to autumn-sown hardy annuals covers the flower side, and the complete guide to growing peas from seed is the closest thing we have to a sister article — peas share the October–November option and almost all the same rules.

Care, blackfly and the pinching trick

Broad beans need almost nothing through spring: no feeding, no watering except in a dry spell at flowering, and a hoe run between the rows. What they do need is a decision about blackfly. Aphis fabae overwinters on spindle bushes and moves onto broad beans in May, always at the soft growing tip first.

The classic answer is also the best one: once the bottom four or five trusses of flowers have set pods, pinch out the top 8 cm of every stem. You remove the tissue the aphids want, and you redirect the plant's energy from making more stem into filling the pods it already has. The pinched tips are edible, incidentally — steam them like spinach. For anything the pinching does not solve, see garden pests and control.

The other thing to watch for is chocolate spot, a botrytis that shows as small brown flecks on the leaves. It is a wet-winter, crowded-plant, low-potash disease, so the cure is spacing and airflow rather than a spray — the same logic set out in preventing common plant diseases. Pod set can also fail in a cold, dry May: the flowers are largely bumblebee-pollinated, and a week of wind and rain at the wrong moment means empty stems. That is weather, not a fault in the plant.

Harvesting: three crops from one row

Pick the pods whole at 5–7 cm long and cook them like mangetout — the most underrated broad bean harvest there is. Then take them for shelling once the pods are 15 cm or more and you can see the beans through the wall; if the scar where the bean joins the pod is still white or pale green, it is at its sweetest, and once it turns black the bean has gone starchy. Finally, leave the last flush on the plant until the pods are black and papery, and you have a bag of dried beans for the winter, dried and stored exactly as described in our guide to drying beans for winter.

When the row is finished, cut the stems off at ground level and leave the roots in the soil. The nitrogen-fixing nodules on those roots are the whole point of putting legumes into a crop rotation; pulling the plants up throws that away. The tops go on the compost heap or, if you are already thinking about the winter beds, alongside your green manures — where the winter field bean is, in fact, the same species.

Common broad bean mistakes

• Watering the seed in — cold, wet soil plus a large starchy seed equals rot. Sow into moist ground and walk away.
• Sowing a spring variety in November — an early, tender type will not come through a hard winter. Autumn sowing needs a hardy longpod.
• Feeding with nitrogen — the plant makes its own. Added nitrogen produces lush growth, weak stems and a blackfly nursery.
• Staking too late — the supports go in before the plants lean, not after. A flattened row in June rarely stands back up.
• Never pinching the tips — five minutes with your fingers in late May is worth more than any spray.
• Pulling up the roots — cut at soil level and leave the nodules behind for the following crop.

Frequently asked questions

How cold can broad beans survive?
Well-established autumn-sown plants of a hardy longpod variety come through around −10 °C, and a good deal lower under fleece or a cloche — see cloches, fleece and cold frames. Cold is rarely what kills them, though. Waterlogged soil and mice account for far more losses than frost does, which is why site drainage matters more than your local minimum temperature.

Do broad beans need support?
Yes, in almost every garden. Most varieties reach 80–120 cm and carry a heavy load of pods on a hollow stem. Double rows with canes and two rounds of string are enough; only the dwarf types at around 45 cm can be left to stand on their own.

Can I save my own broad bean seed?
Easily. Leave a few of the best pods to dry to black on the plant, shell them, dry the beans for another two weeks indoors and store them somewhere cool and dark; forty-eight hours in the freezer first will kill any bean weevil. Note that broad beans are partially cross-pollinated by bees, so seed saved from two varieties grown side by side may not come true — the details are in our seed saving guide, and how long seeds last covers viability, which for broad beans is about three years.

Is it true some people cannot eat broad beans?
Yes. People with the inherited enzyme deficiency G6PD — sometimes called favism — can have a serious reaction to broad beans, including the pollen, and should avoid them. It is uncommon but well documented, and worth knowing if you grow beans to give away. For everyone else broad beans are one of the most nutritious things in the garden, provided they are cooked rather than eaten raw in quantity.

Broad beans ask for one afternoon in November or February and then very little until you are picking. If you are filling the rest of the plot at the same time, our September sowing guide and the seeds to sow this month collection will tell you what else can still go in — a row of winter salad leaves alongside the beans is the obvious pairing, since one bed then feeds you through the hungry months and the other is quietly building next June's harvest underground. Browse the full vegetable seed range, or start with our beginner's guide to growing vegetables and the rest of our growing guides.