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Subject: Re: Iron salts as slug killers
From: Gary Matson <matson@awwwsome.com>
Organization: Verio Northern California's Usenet News Service
Date: Tue, 20 Apr 99 02:07:13
Message-ID: <MOD$990418.27628@rec.gardens.ecosystems>
References: <MOD$990411.6387@rec.gardens.ecosystems>



According to a Gardens Alive catalog I recently received, the escargo
product is iron phosphate. This does not seem related to your iron EDTA
chelate. Are they not telling the truth in their catalog?

EDTA is given to people as a remedy for heavy metal poisoning. I don't know
the dosages, but it cannot be terrifically toxic to humans, which are
mammals, of course. But how 'toxic' iron phosphate might be is a totally
different question. And why it kills slugs would be nice to know too.
What is special about a slug's metabolism that it would be hurt by that
substance?

As far as too much iron in the soil, I cannot understand where that
concept comes from. Perhaps there is a form of iron that is a problem, but
many soils, especially the red colored ones from the south and the sierra
foothills in California have tremendous amounts of iron in them (a hefty
percentage of total material) and are fine soil. Also, people buy ironite
fertilizer all the time, basically buying expensive nitrogen and getting
useless iron in the bargain, but no one worries about their getting to be
too much iron in their soil (and remember, this substance is being used by
the hundreds of pounds, not just a little like a slug bait might be used).
You can have all kinds of rusty iron in the soil, and the plants are not
harmed, nor are the creatures feeding on the plants. If there is a
reference regarding iron toxicity in soil, I'd very much appreciate
learning about it.

There are certainly legitimate and necessary questions to be asked about
the toxicity to every other creature out there, and what it changes into in
time in or on the soil, and what happens to the organisms that eat or
decompose the dead slug. But these questions are not well answered by
mis-stating the substance chemically, or by mixing in non-issues like too
much iron in soil becoming a problem.

Does anyone out there have any sources of good information about this
'escargo' product?

G. Matson

Bill Robinson wrote:

> A number of gardeners in the Los Angeles area are now talking
> about the use of iron salts as slug killers. Gardens Alive sells
> a product called Escargo (spelling?) and there is also a
> product called Slug-O and both of these are promoted as
> iron salts with the pitch that because they are just iron salts
> that they are harmless to beneficials and therefor environmentally
> friendly. Apparently, a lot of it is being sold.
>
> These products, as I understand them, are based on the iron
> salt of eythlene diamine tetra acetic acid or EDTA which makes
> it iron chelate and EDTA is a toxic material. Its something you
> might not want to have around your home garden particularly if
> you have kids or pets. Relatively low levels of EDTA kills mammals.
>
> Iron is one of the essential plant nutrients. As is the case with
> all of the other mineral nutrients, iron needs to be present in the
> soil at certain levels. That is, you can have too little and the plants
> become iron deficient or you can have too much and reach the
> toxic level. There isn't a whole lot of slack between too little
> and too much.
>
> If a person's soil tends to be low in iron, one could use iron chelate
> in reasonable amounts without getting into trouble, If a person's
> soil tends to be iron rich, using iron chelate at high levels for slug
> control could produce problems regarding toxic levels of iron. Couple
> that with EDTA being toxic, iron chelate should not be considered
> all that O.K. or safe.
>
> My guess is that iron chelate is probably every bit as destructive
> to the environment as metaldehyde which is the standard synthetic
> snail and slug poison and more of a safety hazard in terms of pets,
> kids, and/or home gardeners.
>
> Bill
>
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