> We are trying to develop a starting soil along recommendations by Alan
> Chadwick. This soil incorporations 'sharp' (sharp, non-beach, sand). We
> have been told
> that this is just sand from a construction company, but, since we are in
> the certification process and since our goals are to produce pure food, it
> is a little hard to incorporate materials from construction suppliers
> without eing concerned about its origins.
Sharp sand is used in the nursery industry as a propagating medium, alone or
as a component in a mixture used for rooting perennials, shrubs and trees.
Organic growers in my area use a prepared mix such as Fafard or other brand.
Its ingredients comply with organic certification guidelines. I wouldn't
think sharp sand would be optimum or starting vegetable seedlings; herbs are
another matter. It can be easily obtained from premixed&delivered concrete
suppliers as it is used along with portland cement and crushed rock to
sharp sand = washed sand = white sand (not fine beach sand) is a clean (no
topsoil, clay or organic matter), washed coarse aggregate; some particles
can range around 1/8" in size - good for plant propagation because it is
clean, can be easily sterilized, provides excellent drainage and
never compacts (when used alone or with vermiculite, perlite, sphagnum,
peat or screened compost)
mortar sand - sometimes orange in color (around here) is an even aggregate
with average particle size smaller than sharp sand; mixed with mortar mix or
portland cement to make mortar for laying brick, block and stone - this
material is very poor for use in plant propagation as it will easily compact
when it dries out, can harbor diseases and is a less friable mixture for
development of root systems
> Has anyone found a 'reliable' source for 'sharp' sand, or seen it advert.
> in a horticultural supply catalog?
Make your own compost/peat-based mix or buy a standard commercial mix.
I hear that the Cornell mix is a good one.
Lawrence F. London, Jr., Venaura Farm, Chapel Hill, NC USA
london@sunSITE.unc.edu - http://sunSITE.unc.edu/london
email@example.com - http://www.interpath.net/~london
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