growing field beans
Why grow field beans?
Growing field beans can be a great alternative to growing broad beans. They are a hardier, more robust alternative, and produce a greater yield per square metre. The taste test consensus shows that there is little between them in terms of flavour. The main downside we can see is that there’s more podding labour involved because field beans are smaller then broad beans and there are fewer in each pod.- so the same amount of podding time providers you a smaller return in terms of edible beans. If you can cope with that, they are a great alternative and are available to harvest during the ‘hungry gap’ when other harvests can be limited.
Garden Organic posted an interesting article on comparing field beans with broad beans if you would like some further information.
How and when to sow
Field beans can be sown from late October to mid December, and from mid February through until June.
We recommend sowing during the first two weeks of November to over-winter, and if they fail, then re-sowing between mid and late February because they provide an excellent early crop at a time when there’s a limited amount of food ready to harvest.
Whenever you sow them, we recommend doing so in module trays so that they’re ready to plant out as small plugs in a few weeks’ time. Traditionally people would start them in root trainers or module trays with very deep cells/modules, but this isn’t actually necessary; we find that they’re fine in pretty standard sized modules. The ones we use are 42mm wide and 55mm deep.
Alternatively, you could sow direct, but we find that mice/voles tend to eat them, or you can sow in used toilet rolls which works fine, but you end up spending a lot of time cutting/folding/filling them all individually (which obviously isn’t such an issue if you’re only growing a few), and do also note that they will go soggy and look a bit worse for wear by the time they’re ready to plant out – it’s a perfectly fine method though if you don’t have module trays to start them in.
When to harvest/days to maturity
Time to maturity (i.e. from point of sowing the seed, until the crop is ready to harvest) varies dependent upon the variety, and growing conditions. We find that our field beans are ready to harvest from late May/early June if sown the previous November, and when sown in February they tend to be around 3 weeks later; so mid to late June. In our experience they then crop at their best for 4-6 weeks once harvesting has begun.
Recommended varieties
We like ‘Wizard’ field beans.
‘Vespa’ are supposed to be very similar but with a slightly increased yield, though we have not tried them.
How to grow
Once you have sown your seeds in your module tray, toilet roll tubes, or other vessel, you need to keep them warm (around room temperature is ideal) and moist (but not constantly wet – or they will rot) until they have germinated. They do not need any light at this stage.
Within 5-10 days you should see some signs of life, and once you can see some greenery you want to move them somewhere that they will have access to light – such as a south facing windowsill.
As they develop further by unfurling and opening their first leaves (cotyledons) their light requirements will increase. At this stage, if you have access to a cold frame, greenhouse, polytunnel, polycrub, or grow light, then it’s a good idea to utilise one of them to maximise the quality of light they receive. If you don’t have access to any of these then keep them on the windowsill, but you may need to turn them around every so often to prevent them from growing in one direction (towards the light). If the weather is reasonable (i.e. it’s not snowing and we’re not in the midst of a storm) then you could put them outside in a bright, but ideally sheltered, spot during the day, then bring them inside overnight if it’s still very cold (below say 2°C.).
After 3 – 4 weeks, they should have developed into fairly substantial seedlings; big enough to handle now. Their roots should be visible at the bottom of whatever you’re growing them in, and they should also hold the compost together when you ease them out of the receptacle in which they’ve been growing. They are now ready to plant out into their final growing positions outside. If you have been growing them inside your house, or somewhere with supplementary heat, then it’s a good idea to harden them off before planting out, but if you’ve been growing them on in an unheated greenhouse, polytunnel or cold frame then you should be fine planting them straight outside at this stage.
To plant them out, you just need to make a small hole in your growing medium – ideally just slightly larger in diameter than the rootball, then pop it into the hole you’ve made, and give them each some water directly into the planting hole. This helps to settle the compost/soil around their roots and removes any air pockets, Note: you should hold the plants by their leaves when you are handling them, as opposed to the natural tendency to hold them by the stem. The reason for this, is that if you damage a leaf in the process of transplanting, the plant will recover fairly easily. However, if you squash or break the stem, there is a significant chance that the seedling will be damaged irreparably.
Once they’re all planted out, it’s. good idea to lay some horticultural fleece on top of them if it’s still early in the year, and weight it down around the edges to prevent it blowing away. This will provide the seedlings with some added protection from both the wind and cold temperatures to help them get growing. If you’re planting later in the season, or the climatic conditions are favourable, then fleece is an unnecessary step.
All that remains now is to keep an eye on them and provide them with water if there’s been no rain for a while. Remember it’s best to give them a good soaking less frequently than to give them water little and often, as this will encourage shallow roots and they will become dependent upon you watering them, rather than seeking out moisture themselves.
Beyond regularly checking on them to identify and deal with any issues, the only other thing you may wish to do, is pinch out their growing tips once you see bean pods starting to develop at the base of the plants, this is often around late May/early June. Pinching out the tops is thought to deter blackfly from attacking them when they arrive in late spring/early summer. However, this is a completely optional step, and even if you get blackfly (whether you’ve pinched out the tops or not!), the ladybirds will soon be along to feast upon them and they shouldn’t do any real damage to your plants or your crop. In fact, you could argue that it’s better not to pinch them out in order to increase the chance of the ladybirds getting a decent meal!
Pests & diseases
Field beans often attract blackfly in late spring/early summer (although they are less susceptible than broad beans), however, as explained above, these should be dealt with pretty efficiently by the ladybirds when they arrive (usually within a couple of weeks of the blackfly appearing), so no grower intervention is usually required. However, if you are concerned, you could spray the affected areas with water containing a drop of washing up liquid.
Mice and voles can be a pest in terms of eating the beans, although generally this is only a problem for us when direct sowing the beans in the ground i.e. they eat the seeds before they germinate!
In terms of disease, the most common are probably rust and chocolate spot. The RHS website has an article on both chocolate spot and rust. If your plants suffer from either of these, they will likely have already started cropping and you will still get a harvest, they may just not go on cropping for as long, particularly if they are badly affected. You could try spraying a mixture of water, neem oil, and a drop of washing up liquid (to act as an emulsifier) onto the affected plants.
Succession planting options
As broad beans only utilise half the growing season in the UK, there are lots of crops that you could success plant for a second crop in the same area once your beans have been harvested and plants removed.
See the June and July Jobs pages for more inspiration, as seeds sown into module trays during these months will likely be ready to transplant around the time your broad beans finish, but some options include:
- Swede
- Beetroot
- Swiss Chard
- Kale
- Purple Sprouting Broccoli
- Calabrese (large heading broccoli)
- Cauliflower
- Chinese Cabbage
- Oriental leaves (sow in August)
- Salad Rocket
- Coriander
- Carrots
Harvesting
Field beans are best harvested when the pods are approximately 10-12cm (4-5 inches) in length, and when they feel full/firm, indicating that the beans within have swollen to a good size. To harvest, just twist and gently pull/snap the beans from the plants, being careful not to damage their stems. If you leave beans on the plant for too long, they will be tougher and less appetising.