Why Put Soap on Trees?

[Kevin J Harding]

Mark E. Hill (mhill at lexis.pop.upenn.edu) wrote:
> Why put soap on trees?

To clean  them of course!!  ;-)

Now that the obvious silly reply has been dealt with ...
Do you mean a soapy water solution which is often used as a mild 
insecticide to annoy aphids, scale insects and other assorted bugs which 
can be moved on without resorting to more nasty (and expensive) chemical 
preparations.

Cheers,
Kevin H.