How to Protect Broad Beans from Blackfly

Hopefully within the next couple of days I'll be harvesting the first of the broad beans.  I would usually already have had a crop from the polytunnel but regular readers will know that the mice put paid to that idea this year.  Mice are not the only pesky pest trying to get to my beans before me and I noticed, yesterday, that some of the beans had some blackfly on them.

Blackfly or black bean aphid (Aphis fabae) are a species of aphid that love to feed on the tender tips of broad beans and can increase rapidly to the point of even killing a young plant and certainly weakening all plants they infest.  They can quickly spread from one plant to another helped by ants.  The ants feed on the sticky honeydew that blackfly secrete and they have "learnt" to move aphids to new plants in what can only be described as a form of farming.

Broad bean tip infested with blackfly

Young pods infected with blackfly

Because blackfly can be so damaging to a crop of broad beans it is vital that they are quickly controlled.  The simplest method is to be vigilant checking daily for an infestations.  Infested bean tips should be nipped off, together with any offending pests.  If you are not squeamish you can also squash off any blackfly that are further down the plant or that have infected the pods, their second favourite haunt.

Tip removed to show blackfly

Ultimately prevention is better than cure and there are various methods you can employ to keep blackfly numbers down:

7 tips to prevent blackfly infecting broad beans

1. Ensure you have a well manured soil to allow healthy plants to grow that are better able to withstand an attack.
2. Encourage insects and minibeasts in your garden that feed on blackfly including ladybirds, lacewings and hoverflies.
3.  Keep down the number of ant nests in the garden.
4.  Remove the tender bean growing tip before an attack takes place.
5. Be vigilant and check your beans daily.
6.  Blackfly also infest other plants such as nasturtium and weed species such as dock and fat hen.  Keep other susceptible plants away from your beans and keep on top of weeding.
7.  Grow your beans as early as possible (mice permitting!) so that the plants are bigger when the blackfly first attack and better able to survive an attack.

Fingers crossed then I have saved my broad beans from death by blackfly and will soon be eating these delicious veggies ... although my friend JT is no doubt shaking her head in disbelief that anyone can actually LIKE broad beans!!  However look, JT ..... I have actually managed to harvest cucumbers from the plants you and Mr JT gave me.  They may not be huge but they are really tasty.  I have always struggled to grow cucumbers well and was not even going to bother this year until Mr JT gave me 2 plants.  Glad I didn't give up on them and fingers crossed there are more plenty cucumbers to come.

MY cucumbers!!

Are you a vegetable grower?  Have you any tips for growing great broad beans or cucumbers?