Aphid epidemic and soap water

Anybody else suffering with aphids this year? I don't remember having a problem last year but this year.....aphid city.

I read somewhere soap water does the trick, so I sprayed some fairy washup liquid on the little guys and worked a treat (on a side note....why does it work?)

I am just a little concerned that, while my plants are not at deaths door, they don't seem to have responded well to being covered in fairy. Is there a recommended type of soap to use?

They started camping out on my sunflowers and now have taken a liking to my courgettes, but being my staple crop I am hesitant to give them the fairy treatment before I know it's now what made my sunflowers unhappy.

Any thoughts?

 

It blocks up the holes in their skin, through which they breath - or something like that. Its something to do with interfering with the moisture content of their skin.

I use a Horticultural Soap. I am forgetful of the chemistry, but its something like washing up detergents include Phosphates, which Horticultural Soap doesn't, and that tends to be what upsets leaves.

I mix some Neem Oil with the Soap in my sprayer. That helps see off quite a lot of critters and the Soap, when that alone doesn't work, acts as a surfactant to get the Neem Oil to "stick" to the critters.

These are "contact" solutions though, rather than systemic, so you will need to repeat every day or two until you have control, and then less frequently.

Try spraying a couple of leaves to see if the plant objects before doing the whole crop. I drench the crop [with the hose spray nozzle] a couple of hours after spraying to remove any residue, and I put up with some leaf-loss on the crop in return for annihilation of the pest

 

Thanks Kristen