dunno about the taste, but if the washing up liquid's not eco stuff, it won't do them much good as plants.

Totally agree unless you are using an ecological washing up liquid don't put the water on your garden it will pollute the soil.

Hi there,

I'm afraid I agree, unless it's Eco and not fairy there is not a lot you can do with washing up water,
I've used very diluted soapy water to zap green fly, but it was clean water and not re-used.
Happy gardening.