This is an interesting question and I think
it really highlights the wide variety that can
be found in living organisms! The answer to your
question, simply put, is: it depends on the
plant and what kind of alcohol you give it.
Different organisms have slightly different
enzymes, which you can think of as a little
factory that converts one chemical into another
chemical. In the case of alcohol, the enzyme of
interest is called "alcohol dehydrogenase" --
but it turns out there are many types of alcohol
dehydrogenase. These dehydrogenases are found in
many living organisms, but they vary between
different species (i.e. even from plant to
plant, and mammal to mammal). To further
complicate things, there are different kinds of
So let's talk about a couple of examples to
give you an idea.
1. When you give a plant ethanol -- the
kind of alcohol people drink -- in many cases
its growth will be stunted, or even worse: it
will die. Poor plant! (By the way, even moderate
amounts of alcohol will shrink the human brain.
You can Google images of brains and numbers of
2. However, giving a plant methanol -- the
kind that people should never drink! -- can
actually stimulate growth in plants!
As with many things in biology, the answer is
complicated! I hope this helps!