In article ,
Martin Brown wrote:

It is more effective just to spread the coffee grounds around sensitive
plants like hostas and delphiniums. Turning it into a spray isn't worth
the effort. Most things of plant origin that we consume as stimulants
and interesting tastes were intended for chemical warfare against plant
parasites or fungi. It is sheer good luck that they do us no harm.

Not luck! We are evolved from a long history of plant eaters, and
have a very high resistance to many such chemicals - caffeine being
one. And we don't usually consume the plants which contain ones to
which we have no resistance, however interesting they are.


Regards,
Nick Maclaren.