In message , Jaques d'Altrades
writes
The message
from "Franz Heymann" contains these words:
"John Edgar" wrote in message
...

My roses are still growing hard here in Sussex, and because of the
dryness and heat we now have the dreaded aphids making a return visit.
I don't want to use Rose Clear etc, and have heard that they do not
like soapy water. Is this true, and if so what sort of soap and what
strength of mixture is best? Will dilute washing up liquid do the
trick for instance?

Washing-up liquid is not soap.

But it does the trick.

Any wetting agent will interfere with insects respiration.
Soft soaps are more effective and gungy.

You do have to be careful what you use it on. Some plants do not like
this treatment. I defoliated a bay tree once this way. It stripped the
surface waxy coating and the leaves desiccated within a few days of
application.

Regards,
--
Martin Brown