How To Get Rid Of Black Fly On Plants? Gardening Help

Last Updated on April 8, 2024 by Real Men Sow

The blackfly showed up on my vegetable patch. This was earlier than I’d been expecting, and interestingly they’d made a beeline for my overwintered broad beans. I don’t normally overwinter broad beans, but late last year I had a few seeds and missing the buzz of germinating seeds I sowed them under a cloche. In this blog I’ll share how to get rid of black fly on plants, so you can prevent this nightmare in your garden too.

Where Are Blackflies Found?

I’ve often heard that overwintered broad beans are less susceptible to black flies, so I was interested to find out if this really was the case. I hear this advice every year, and I often wonder if it has any truth or is one of those old tales of allotments past. Fortunately, I caught the blackfly early, loitering on a single bean pod, and quickly tossed the whole thing in my Council garden waste bin.

Getting Rid Of Black Fly On Plants

Although commonly known as a broad bean lover, blackfly, unfortunately, attack lots of other allotment favourites, such as courgettes, French beans, and runner beans. They’re a sap-sucking insects that attacks young growth in large clusters, weakening the plant and stunting its growth.

How To Get Rid Of Blackfly On Runner Beans, Courgettes and Strawberries

It was my young runner bean plants that have taken the hit so far this year. Out of nowhere, the blackfly had taken over pretty much every plant around my wigwam. Having only just discovered woodlice eating my strawberries, I got all overcome and melodramatic, exclaiming it as a difficult growing year and writing off runner bean recovery before I’d even made any effort to save them.

I cleared my head and made my way into the kitchen. It was time for soap and water.

What Are the Best Tools to Get Rid of Black fly on Plants?

Hot, soapy water, sprayed over the infestations is the best way I have found to deal with black flies. You have to stick at it, as getting rid of them may take several days of spraying but I’ve found that eventually, this method does work. I’m not sure Fairy Liquid is purest organic, but it’s just about good enough for me…

Wash Plants to Get Rid of the Blackflies

Lewis thought ‘washing the plants’ (and everything else on the patch) was great fun, but I’m not sure he enjoyed squishing the little bugs as much. I really can’t describe how odd squishing blackfly between feels, but it really is strange. You’ll hopefully know what I mean, as I think this might be one of those things that only a veg grower understands.

How long does it take to get rid of Black fly?

Three days later and it looks like everything is going to be okay. The blackfly appears under control thanks to good old Fairy (other washing up liquids are available), and Lewis and me have found another garden job we enjoy doing together.

Nasturtiums as Sacrificial Plants for Black Fly

Another tip I have used in the past is to grow nasturtiums as sacrificial plants. A load of nasturtiums are as cheap as chips and blackfly loves them. Planted out amongst the beans and courgettes, the blackfly will attack the nasturtiums instead of the veg plants. Of course, this method cannot be 100% successful, but I’ve found that it does reduce the amount of blackfly on the beans.

Final Words On Black Fly On Plants

I suppose the moral of the blog post is don’t panic if you discover blackfly. It’s not the end of your crops. Just get rid of the blighters with some soapy spraying and thumb and forefinger squashing, and with a bit of luck, all will be okay.

If only dealing with those pesky cabbage whites was as easy.