dahlia problems

[the big lebowski]

hi all,I bought about 25 dahlias from wilkos and started them off indoors then moved them outside some now have lots of little green and black flys on them ive tried spraying them with a mix of water and washing up liquid and it seems to have got rid of the green flys but not the black ones ,any ideas ? thanks ps id rather not kill the flys just get rid of them if possible

[WendyC]

Could you blast them off with a hose and more the plants away from where the little blighters fall.

[the big lebowski]

I`ll try that later,some are in pots so they could be moved so I`ll try that too ,cheers