eco coco
CEC of the coco (this is so the medium
does not retain ions such as calcium and
iron). Further processing of some highvalue coco growing mediums can also
occur, which includes pre-conditioning
and buffering so that the substrate has
minimal effect on the composition of the
nutrient solution surrounding the
root zone.
Because coco is a natural product, there
are variations in the chemical and physical properties of this medium depending
on its source and supplier. Suppliers of
high-grade coco carry out regular testing
of their product to check for any irregularities in supply and then correct for
these. However, while there are excellent
brands of coco on the market, these are
also still poor-quality supplies still being
sold as a cheap growing medium. As such,
growers need to select and only use a
reputable brand.
Getting the best from coco—different
products for different uses
There are many different grades of
i
horticultural coco and some have been
specifically designed for different plants
and systems. While orchids prefer a very
coarse coco chip, the propagation and
germination of small seeds requires a
much finer grade that will hold sufficient moisture and oxygen. While the
high water-holding capacity of coir dust
is great in some situations, it can create
problems with over saturation of the root
zone, and grades of coco commonly used
in grow slabs tend to consist of a mixture
of longer coarse fibers, or flakes, of coco
that keep the substrate open and aerated, and finer particles that hold more
moisture. These grades of coco are ideal
for longer term hydroponic crops, such
as tomatoes, cucumbers, melons, peppers
and cut flowers, because the fibers help
prevent the substrate from packing down
over time. These properties mean also
high-quality coco fiber can be used for
many successive crops before finally being
recycled as a soil conditioner or mulch.
Aside from different grades, coco also
comes in a range of different products—
from differently sized compressed bricks
to grow slabs to pre-expanded, ready-touse bagged product. Compressed bricks
of coco fiber keep the cost of shipment
to a minimum—a typical 11 lb. block
of compressed coco can be expanded in
water to create over 17.17 gal of growing substrate. Another advantage of coco
106
Maximum Yield USA | September 2012