Save the world: grow beans and peas

Alys Fowler
Photograph: Getty Images

Legumes might just save the world. Stuff all this lab-grown meat and those cricket burgers: legumes are what we should be banking on. The protein-rich seeds of beans, peas and lentils are nutritious, easy to grow and leave the world in better shape, thanks to their relationship with soil bacteria.

These bacteria are known as rhizobia. They take atmospheric nitrogen, which is useless to plants, and turn it into forms the plant can use, such as ammonia. They also make the phosphate in the soil, which is essential for plant vigour, soluble, and produce hormones that help the plant develop and fine-tune its pest defences. In return, the plant houses the bacteria and ensures there is a good supply of oxygen and plenty of raw ingredients such as carbon and nutrients.

Rhizobia root nodules provide beneficial bacteria. Photograph: Alamy

It is a pretty sweet deal, but the amazing thing is that some of the nitrogen produced is sent back into the soil, available to other plants and the soil food web. This is why you should never dig up your peas or beans, just cut the plant back to soil level and allow nature to do the rest. The rhizobia in the nodules is released back into the soil, inoculating it for next year’s beans; any leftover nitrogen will be supped up by whatever you replace it with.

Related: How to grow Mexican fleabane | Alys Fowler

These days, I grow more beans and peas than I do any other crop, from dwarf varieties that I plant between taller veg to rows of climbing ones. Right now, some of you are probably tucking into fresh peas, snapping mangetout or steaming the first harvest of thin french beans. Although I love the flavour and tenderness of immature pods and beans, I concentrate my growing on stuff that will store through winter. Many of these beans I will harvest, shell and dry: they will fatten up by autumn, giving me jar upon jar of meaty, nutty, sweet, creamy beans that feed us through the hungry gap next spring. It’s also worth freezing fresh fat beans whole, particularly borlotti. Once defrosted, they cook as quickly as fresh and can be added to soups and stews without prior soaking.

Borlotti beans can be frozen whole. Photograph: Alamy

If you haven’t grown any varieties specifically bred for drying, try saving whatever you are growing as an experiment: runner beans and climbing french beans are ideal. The runner beans ‘Czar’, ‘White Emergo’ and ‘Scarlet Emperor’ are all delicious; my favourite, ‘Black Coat’, is sublime in its nuttiness. ‘Blue Lake’, ‘Cherokee Trail of Tears’, ‘Rattlesnake’ and ‘Zolfino’ are a few of the many french beans that have a good flavour. Stop picking around mid-August, to give the beans enough time to fatten up before the autumn rains appear and spoil the crop. The beans are ready when they rattle inside the pod.