The Importance of Insects to Broad Beans And Vice Versa

By Gavin Anderson

Broad beans sown last year or very early in the spring will be in flower this month and thoughts will be turning to ensuring pollination for these early broad bean crops. Broad beans are capable of self pollination, as seasoned gardeners will be at pains to point out, but studies have shown that those which were insect pollinated provided a bigger yield of beans. So if you want to be harvesting abundant broad beans this year then it is important to attract insects to help you pollinate the crop as effectively and efficiently as possible.

Though these insect helpers are not essential for any beans to form, if you want to maximise yield then you definitely need to make sure that the other planting around your broad beans is insect friendly. Companion plants for your broad beans will encourage pollinators to approach and once in the area, they will stay to pollinate the flowers of the bean plants.

If you have not grown companion herbs and flowers from seed already, now is a good time of year to invest in a few bedding plants to fill the gaps that you have not yet been able to in your kitchen garden. Marigolds are a good choice and should be dotted throughout the vegetable garden. Lettuce and other crops can provide good ground cover beneath your beans which will reduce the amount of water lost to evaporation if the weather is warm and dry. Leave some lettuce to go to seed and bees and other insects will love the profusion of flowers. Leave radishes to go to seed nearby and their flowers will also help – plus, later, you will be able to harvest radish seed pods, which make a delicious snack.

By growing broad beans in a mix of other flowers that are attractive to pollinators, you are creating an extremely bee friendly garden. Just as the broad beans will do better if there are some bumble bees, honey bees and other pollinators, so those pollinators will be better if given the plentiful supply of nectar that the broad beans provide, often before there are many other such abundant sources in the garden.

Bumble Bees love broad bean nectar so much that though the long-tongued bumble bee is the only one able to reach the nectar 'officially', short-tongued bumble bees are keen to get some too – so much so that they often snip a little hole at the base of the flower and steal some that way. Honey bees will also take advantage of those holes to get some nectar for themselves.

So, though broad beans do not strictly need insects for pollination, they will do better with them than without. The bees and other pollinators will also very much appreciate the abundant source of nectar that the broad bean flowers provide. If you are growing broad beans in a polytunnel or under cover, make sure that insects can still gain access and eave entrances open whenever possible to allow free entry for bees and other insect helpers.