Re: [tomato] blights

Thomas Giannou (
Wed, 28 Apr 1999 12:18:16 -0700

Dear Olin,

Just curious... why would rock dust be inappropriate to desert soils?  I did
a pH test and it is real close to 7.0.  Perhaps in your soils mineral
depletion by plants may not be a problem?   I have never seen rock dust
locally here in Spokane in any of the stores.  There seems to be a fair
following on the internet on the subject.  I know it gave me a headache when
I spread some of it on a portion of my brothers lawn... drop spreading seems
to be prefferable to broadcasting it out... and a dust mask would be wise.
The company that sent me a sample showed an analysis of 58 different
elements in their rock dust.

Most fertilizers and other additives don't have much in the way of minerals
present, so it seems like a good way to replenish soils with minerals.
There is one thing that bothers me about adding such stuff to the soil... it
has a cumulative effect.  So, if there are heavy metals present... and there
are, then they would accumulate.  I've asked the Washington Department of
Agriculture Fertilizer people to give me their opinion about using rock dust
that contains traces of heavy metals.  Here in Washington State, they seem
to be real particular about those sort of things.

It appears that the 6% iron content was enough to interact with the moss in
my brothers lawn.  The moss is turning black after a couple of days.  I put
a couple of tablespoons of it around my sweet 100 cherry tomato plant which
I am growing inside.  I don't think there will be adverse effects, but it
will be interesting to see how the plant does.


-----Original Message-----
From: Olin <>
To: <>
Date: Wednesday, April 28, 1999 11:33 AM
Subject: Re: [tomato] blights

>My objective was to point out that the narrow technical definitions of
>organic chemistry did not necessarily carry through to the definitions of
>commonly accepted  "organic" gardening practices.  I would concede there
>seems to be a fair amount of hair-splitting as to which compounds and
>practices are or are not "organic".
>As to rock dust, I have no idea as to it's "organic" gardening
>acceptability.  It is not available locally and would be inappropriate to
>our desert alkaline soil.