Xi Wang wrote:
Hey list,

I was curious, many have said that 3% hydrogen peroxide is a great
way
to kill bacteria, fungi...etc, but if it can kill those things, why
doesn't it harm the plants? It's cells either way right?

Are plant roots more susceptible to H2O2 damage than leaves (if in
fact
damage can occur)?

Cheers,
Xi

H2O2 (hydrogen peroxide) gets touted as a general greenhouse antiseptic
from time to time, usually in a much weaker dilution than 3%. This
claim seems dubious to me because H2O2 breaks down into water and
oxygen very rapidly, especially on contact with organic material. I
don't think very dilute solutions would be any more effective than
plain water.

Whether 3% H2O2 would harm roots and leaves, I don't know. I don't
have any plants I'm willing to sacrifice to find out.

Highly concentrated H2O2 is very nasty stuff: ask any chemist. I
mention this only because H2O2 enthusiasts often recommend folks buy
strong concentrations to formulate their own weak solutions.

J. Del Col