July 2024 - A6

SPECIAL ADVERTISING SECTION
ORGANIC INGREDIENTS
of
GROWING MEDIA
Coconut Coir - Coconuts are grown
in briny water so coconut coir must
be washed to reduce excessive
levels of potassium, chloride, and
sodium before it is used in growing
media. Some manufacturers offer
buffered coir, which is leached with
calcium nitrate to reduce potassium,
chloride, and sodium levels. Although coir resembles peat
in color, coir has a higher pH around 5.2-6.5, so it requires
little to no limestone, it does not require a wetting agent
and does not settle as much as other components within
containers. Water holding capacity and air porosity are
similar to Sphagnum peat moss.
Pine Bark - For this byproduct of
the lumber industry to be used
for growing media, pine bark
must be screened, graded and
allowed to 'age' in large piles to
partially compost to stabilize the
carbon:nitrogen ratio. Pine bark is
used to improve bulk density, reduce
the water holding capacity of growing media and may
increase air porosity. The pH varies from 4.2-6.0 which
means it requires some limestone, it can produce heat
if it is not properly composted and can have high levels
of certain micronutrients. Depending on its level of
composting and resulting C:N ratio, bark can draw down
nitrogen, therefore growers may need to increase nitrogen
application rates by up to 20%.
Wood Fiber - Wood fiber is made
when pine wood flakes or wood chips
pass through mechanical screw
presses that, in combination with
high temperature and hydraulically
pressurized water, shred the wood
into fluffy wood fiber. Wood fiber
A6 | Premier Tech InFocus
By Ed Bloodnick, Director
of Grower Services, and
Troy Buechel, Horticulture
Specialist - Mid Atlantic US
Premier Tech Growers
and Consumers
Whether you blend your own or buy a preformulated growing medium, a variety of different organic materials such
as Sphagnum peat moss, bark, coir, wood fiber and rice hulls are available for blending growing media. All of these
materials are important for commercial growers in forming the base of growing media; however, there are differences
outlined below that can influence your cultural practices.
increases water holding capacity or growing media,
reducing watering frequency, but still has good air porosity.
Wood fiber has low E.C. and a pH of 5.0-6.5, requiring
little to no limestone. It has a low buffering capacity so pH
can change more rapidly than other organic components;
therefore, the pH must be closely monitored. Wood
fiber has a high C:N ratio which can draw down nitrogen
requiring growers to increase nitrogen application rates
by up to 20%.
Sphagnum Peat Moss -
Sphagnum peat moss is harvested
in its natural state using vacuum
harvesters and graded into various
particle sizes to be used to make
various growing media. Sphagnum
peat moss is naturally low in nutrient
content, has a pH of 3.8-4.5 which must be adjusted with
limestone, and has a waxy cuticle so a wetting agent is
required to help it wet with water. Sphagnum peat moss
has a high water holding capacity and good air porosity.
Peat moss has virtually no immobilization of nitrogen and
has some buffering capacity to minimize pH fluctuation.
Physical Properties of Media Components
For more information on growing media and which
components are best for your needs, contact your
technical support representative from your growing
medium supplier.
Source: Premier Tech.

July 2024

Table of Contents for the Digital Edition of July 2024