Pests & Diseases, Vegetable Garden

Pinch out Broad Bean Tops

My broad beans are flowering and beginning to form small bean pods lower down on the plants. I spent a few minutes yesterday pinching out the tops. Pinching out broad bean tops helps to avoid an infestation of black bean aphid, it also encourages the plants to direct their energy into forming nice big pods of beans rather than putting on more top growth. It’s easy to do, just pinch the very tops off with your thumb and forefinger once the lower pods are approx 3in long. If you see clusters of black dot like creatures, often with a sticky substance covering them, this is black bean aphid. Pinch the tops off as normal to try to bring the problem under control.

If you’re a wildlife nerd like me, you might be interested in another way of knowing if your broad beans have black bean aphid infestation – keep an eye out for black ants on the plants. When feeding, black bean aphid secrete a sticky, sugary substance called honeydew. Ants ‘farm’ the aphids, milking the honeydew produced by the aphids as well as moving them to the fresh new growth. Apparently the sweetest honeydew is produced by aphids eating the youngest, freshest leaves – that’s probably why broad bean tops tend to get infested so easily.

Once you have pinched off your broad bean tops don’t throw them on the compost heap, try eating them instead. They can be cooked like spinach or add to a stir fry –  just make sure they’re not infested with black bean aphid first!

9 thoughts on “Pinch out Broad Bean Tops”

  1. I experienced the aphid and ant problem last summer, despite pinching out the tops. Your beans look wonderfully healthy, well done. I think I may have planted mine a bit late as I grew them with the children here. Caro x

  2. I love Broad Beans, I am about to sow my winter crop. It wasn’t until I watchd Gwynyth Paltreow cook with them that I became a lover of broad beans. Normally I pinch out the tops and pop them in the soil, next time I will add them to a stir fry!

  3. Good advice :) Normally we pinch ours out, pop them in some foil with a splash of olive oil and white wine, seal them in and pop them on the BBQ for a wee while. Sadly, the weather has not been obliging so we have to do it indoors :(

  4. Interesting to read about the relationship between the ants and the aphids, that’s something new I’ve learned today! I have been far to slack with my broadbeans and many of them are covered in blackfly. I have to squash them with my fingers which leaves quite a mess on the stems. As I don’t use chemicals there isn’t much choice but to take this approach but hopefully it will stop the plants (and the pods!) being consumed. I’d be interested to hear how you get on having pinched out the tips; I’ve have done this in previous years but it never seems to stop the blackflys, even nasturtiums fail to do the trick.

  5. Your beans are looking good, Karen. Let’s hope it will have been worth your while, this year.

    I planted Tagetes around my broad beans at the weekend. They are meant to deter blackfly, or possible attract them to themselves and away from the broad bean plants. It would have been better if I’d done it earlier, though as some already had blackfly. I didn’t pinch out all the tips because some of my plants are a bit short, but I might have to. I’ll check to see how it’s going later in the week.

  6. Would it be ok to throw infested broad bean tops into the chicken run? I am doing research as I have not yet bought my chickens yet, they are due in September.
    Thanks

  7. I have a problem where virtually all the flowers are just dropping off. When I looked closely there appears to be a tiny hole at the base of the flowers, presumably made by some insect. Pods are not forming as the flowers drop off at their tiny stem. Any ideas?

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