[Sweet Pea 2]

I went down to the allotment, and I have got loads of black fly on my runner beans.  What is the best way to get rid of these? 
Hoping they won't have totally destroyed them by the time I can get there tonight.

[Brassica Blaz]

ive got black fly like aphids on my greyhound cabbage.my lotty nieghbours said they have them on there beans too,but i dont know what harm they will do ,if any?.i think i heard one chap say he was going to spray them. 

[Lardman]

Organically ? Just run you're fingers over them - makes a squashy mess but you'll kill enough to keep the problem down. Companion plant - attract things that feed off them, ladybirds etc.

You used to be able to spray with home made stuff, something like a very weak solution of washing up liquid, or some soaked tobacco / rhubarb extract. But thats now against the law and you'll spend 40 years in solitary confinement at her Majesty's pleasure if the thought police catch you.    

Chemically Spray with a blackfly killer, Im using Bayers Greenfly plus this year - and frankly its pants.

[Minty]

We just spray with a weak solution of washing up liquid and that works a treat for most things,I dunno why but the cheap stuff seems to work alot better.

[Sweet Pea 2]

Thanks for advice.  I am going to try the weak washing up liquid trick.  I had a look a tthe sprays but they say don't spray in direct sunlight.  This is a bit difficult at the moment

[HLS]

Wouldn't you be risking scorching by spraying any liquid onto the leaves if it's going to be in full sun for any length of time afterwards?  (That is, it's the fact that it's liquid that's the problem, not the specific sprays)  Either way, you may be best leaving it as late in the day as you can, in this weather.

So far the blackfly seem to be concentrating on my nasturtiums.  Fingers crossed...
 

[plainfield57]

working in the old gardens we just crushed them off with our fingers no spraying it was the morning job