Growing on Coco: Busting the Myth

[Newbud]

Found this a while ago and have found it helpfull so thought i'd share it.

Growing on Coco: Busting the Myth
by Ralph B. Par
The Indoor Gardener Magazine Volume 3 - Issue 6
In my travels and correspondence around the world, I find there is much confusion about the use of coconut husk litter,
commonly known (after aging) as coco peat or mulch, in crop production. I was first made aware of the produce as a potential
additive to mineral soil or light peat mixes in the early 1980s. The thinking then was that it had too many issues to use as a
straight mix, but did have some interesting side results when used as a fraction in a potting mix, or as a soil amendment to
improve soil structure. It was first introduced to the Royal Botanical Society in 1862 and proved successful initially but
dropped out of favor because of its inherent issues. Now it has exploded onto the scene in all manners of sue, from fraction
to complete, but what are we dealing with, and why such a delay before it was accepted into the general market?
To start, the physical characteristics of coco are unique, in that it changes its physical and chemical characteristics
dramatically over time. Green or newly harvested mulch is actually the dust (and broken fibers) generated by removing the fivers
from the husk of a coconut. THis matter is unusable at this point. After several months of decomposition, it begins to take on
some usable characteristics: it holds moisture better and releases potassium and other salts slower, down to a reasonable level.
Its structure also remains intact. There is a fairly short period from this point during which the coco peat is usable in
container plant production.. Ideally, the coco peat has to go further to actually work with the plant correctly, but by then
much of the structure is lost and the usable time in situ is severely shortened. While later stages of coco degradation are
very acceptable as a soil amendment, the are not suitable for direct use. Structural problems are, however, a small part of
the issue.
Water moves from an area of low EC to an area of higher EC in an attempt to balance out or achieve equilibrium; where a
semi-permeable membrane isolates the two solutions, only certain elements or molecules can cross, typically a water molecule
or smaller (selectively permeable), through the process of osmosis (Fig A). Membrane can also be selectively permeable,
allowing certain sizes of particles to pass while restricting others. In typical soils and container mixes, fertilized at
recommended levels, the EC of the root zone moisture (which includes nutrients [salts]) is lower than the internal EC of the
root cells, allowing water to move, or diffuse, across the barrier membranes. As the root zone's EC reaches the EC levels of
the plant, water movement slows and eventually halts. Unfortunately, it does not stop there and can move the other way, but
not all. To compensate and get the water in the seawater solution (a solution of water plus many different salts) to move
through the plant, the palm concentrates salts in the areas between the cell walls, known as interstitial spaces. This
effectively shows an increase in the internal EC while allowing the actual cells to function normally. The process of harvesting
the fivers also increases EC levels, because the coconut husks are first soaked in seawater (the most abundant water supply near
where coconuts grow), which imparts its salts into every pore of the coconut material. When decomposition occurs, these salts
come out in very high amounts, especially potassium, the most prevalent element found as an ion (salt).
All usable nutrients become available to the plant's internal processes as ions, or charged atoms or functional groups like
nitrate. Ions affect each other. In fact, they combine in a controlled fashion, in a solution with other ions and no controls,
they still combine or associate with other ions of opposite charge. They also affect the availability of each other as similar
charges. This is known as antagonism, where one element in a large amount will decrease availability of another in a smaller
amount. In this case, as the concentration of potassium increases, the availability of both calcium and magnesium decreases.
It is more commonly known as locking out. When combined with the effects of pH and temperature, precipitation of these salts
can occur. The effect works the other way. When calcium increases, potassium availability decreases. Additionally, potassium
has the ability to almost move at will throughout a plant, as it is mostly unregulated, a characteristic all plants have adapted
by harnessing these ions to do work as they move around.
This is all well and good, but how does that affect the use of coconut peat/mulch with plants? As the coco decomposes, it
"gives off" salts that increase the EC of the medium, which will result in burning and imbalances in calcium/magnesium and
potassium ratios; the "greener" the coco, the worse the problem. About the time this "give off" slows enough to really grow a
crop in, the structure has the characteristic of muck peat and requires amendments like perlite, sand, pebbles or other large
particles added to it to give the medium air. Also, the state of decomposition is at its highest, so what is left will not last
long, and can easily be washed out of the container. We know that if the level of salts AND the ratio of these salts could be
controlled at an earlier stage, we would have the advantage of good physical structure and proper nutrient balance.
Coconut peat has some wonderful physical properties that greatly benefit plant growth. To begin, it is renewable - no stripping
of nature's resources. It makes use of the final product left over from cultivating and harvesting the much-prized nut. At the
right point in its decomposition, coco peat can be used as a stand-alone medium with no need to add perlite or other persistent
amendments. Coco peat itself is fairly pH-stable and buffers the pH well, in a very acceptable range for plant growth. WHile
they are fairly solid and big early on, once the peat particles are treated and decomposed to a certain point, they are like
sponges with micro-pores that hold water, away form the plant roots but available to replenish the larger pores the plant root
can access. This effectively limits excess water while retaining water reserves. These particles hold onto no ions, only what
may fill and dry on the particles themselves. So as long as the medium is moist , nutrients are available. At the proper point
of decomposition, the particles form the perfect combination of air-to-water, because of the different fractions now present,
which can actually mean more air space to water pace, with the micro-pores holding a reserve of water, giving a nice water buffer.
Unlike peat moss, it has no oil on its surface, so wetting the particle is never an issue. The key in all this is to decompose
the particle to the perfect point. The problem is still that the rate of salt release remains high at this perfect point.
Controlling the decomposition process, adding the correct nutrient buffer to adjust the ratio, feeding the plants the proper
ratio of nutrients to offset the coco's "giving off" will produce the perfect growing conditions. When the medium is not taken
into account, the results can be disastrous. Even when fed correctly, and the correct "buffer" of nutrient ratio set up, just
one watering with plain water will wreck the buffer, sending the plant and medium into shock and rapidly escalating the
potassium level. Consequently, plants that do not have enough of some ions like calcium (there are several) due to underfeeding
or washing out will show a deficiency in these and other elements. Meanwhile, potassium builds up the plant tissue, ultimately
leading to margin burning on the leaf surface, mostly at the tip. The first thing the inexperienced grower assumes is that he
is overfeeding and has salt issues. He will decrease the feed concentration and leach the medium. This, of course, magnifies
the problem and makes it worse. The key to proper coco growing is to use the right feed to balance the products the coco gives
off. Think not only about availability, but about the ratio of one mineral to another as well. It is also important to water
correctly.

 

[Newbud]

Coco peat holds about 33% more moisture then similar grades of peat-based mediums if its structure is sound. Since a great
amount of this is tucked away in the micro-pores, the medium can look dry but still be plenty wet. The same rules apply here
as in soil or soilless mixes: water when the container loses 50% of the maximum water it will hold against gravity (immediately
after drainage of a newly watered container). This is done by weight and yes, it does change with time, root mass, humidity,
temperature and grower temperament (thumb on scale syndrome).
By controlling the decomposition and particle size closely, there is no need for anything to increase drainage, like perlite,
and this removes a disposal concern. Even more air space can be achieved by increasing the fraction of coco fibers and husks.
This results in a totally renewable and biodegradable medium that resists compaction. Finally, the pH of the medium, when
buffered and controlled, remains constant pretty much throughout its useful life. The medium sets its pH at between 5.2 and 6.2,
a perfect range, and will hold it there, unlike peat-based products that try to go back to a pH of 4.5 or less within three
months of being planted. By using the correct age of coco with the right porosity, coco potting medium should be able to work
through almost a year's worth of crops before being changed. The pH stays correct and only the structure changes, limiting the
useful period.
So, we see that by controlling the aging process, using the correct ratio of nutrients, using the correct composition of
nutrients, and pre-buffering the coco peat, growers can anticipate getting the perfect medium, correctly balanced, correctly
composed, with good porosity, a water buffer, and a lot less headaches then peat-based soilless mix products. That is great
for a start, but to complete a crop, it is critical that the correct nutrients be used as well. Consider coco as needing to
be "fed" along with the plants. Once the medium establishes a buffer, which it will do based on the nutrients it sees, right
or wrong, the grower can wipe this out by applying plain water to the medium. The medium hangs on to nothing and will readily
flush away its nutrients; then the plant will suffer until the buffer is restored. Always use fertilizer when you water coco
that a plant is actively growing in, at least at about EC = 0.6mS/cm3. This will hold the balance or ratio of the nutrients to
each other and insure that the plant gets exactly what it needs.

by Ralph B. Par

 

[Rockster]

Thanks for that Newbud,I found that very interesting as I'm using coco for the first time as it happens.

I was aware coco is washed with seawater but you'd think some bright spark would try to get a clean supply as surely it would remove half the problem with its manufacture?

Bloody glad you don't need perlite,satans scabies,yuk!

 

[Newbud]

There is more but it read a bit like an advert but i guess it wont hurt to show it

Coco is an ideal medium. Plants thrive in coco when everything is right. One company provides all the right components: Canna.
Canna, always researching new pioneering ideas in the horticultural world, began exploring the coconut option when the peat was
just giant piles of debris left over from fiber production. This debris was deposited around the landscape of producing countries,
forming giant, rotting piles. Each year, these piles grew higher. Initially these were the sources of coco peat for Canna, but
before bringing the product to market, Canna recognized the need for higher controls in order to receive the coveted RHP
(Association for Regulations on Commercial Potting Soils) standard of Holland. Canna began controlling the product from harvest
through treatment, and into giant concrete bunkers to let it age to the exact level needed. It is then buffered, packaged and
delivered to the market. All this is done without steam sterilization, which resulted in other beneficial consequences.

By avoiding the steam sterilization to ensure RHP acceptance, Canna also avoids chemical changes in the medium, nitrate
conversions to nitrite forms (toxic to most life forms), and best of all, the natural Trichoderma, inherent in coco, remains
active, providing a level of protection to the crop that no other company can provide. The structure remains intact, the
potassium release remains a known variable, and the product is still delivered free from weeds, insects, disease and other
soil-borne problems. As it does for all its product lines, Canna believes in the complete package concept. Avoiding errors is
essential. The coco growing "system" medium and nutrient line-up, was engineered through years of in-house research and
countless field tests to provide the correct growing solution, the exact composition and concentration of all the things
required for using coco as a growing medium. Canna Coco nutrients (and COgr) are designed to work with the exact properties of
Canna Buffered Coco (and COGr board). There is no better or easier way to begin and continue the coco growing experience. For
even more info on Canna Coco, get the Coco leaflet or Coco InfoPaper at your favorite gardening store or check out the Grow
Guide at CANNA Canada Corp. - Home.