Wheatgrass Grown in Coco Coir |
While I am a strong proponent of soil-grown, it has caused
me a fair number of infrastructure problems in my growing operation throughout
the years. Soil definitely has its
place, outdoors and in greenhouses, but for an indoor growing
operation—in my case, a 300 square foot year-round, climate-controlled growing
room akin to a laboratory setting—it wreaks havoc and has caused me innumerable
problems in the way of soilborne pathogens, dust, odors, storage limitations,
and physical injury. Even when one works
as cleanly as possible, soil has a way of taxing indoor air cleaning systems, which
can turn into hundreds and even thousands of dollars in maintenance costs when the
system unexpectedly and prematurely fails because of fine dust buildup.
During the years when I was growing primarily in soil, I was
also experimenting with soilless media for my floral wheatgrass crops. Call me crazy, but I just didn’t like the
idea of putting soil on a fancy dinner table for the above-mentioned
reasons: pathogens, dust, odors. Also, soil wasn’t the easiest thing for
florists to work with when they needed to cut pieces to fit their decorating
needs. So I began growing in coco coir (ground
coconut husks), which turned out to be an exceptional growing medium. The simple fact that it is not soil is what makes it
a hydroponic growing medium, and thus began my journey as a hydroponic grower. Coco coir looked and acted just like soil,
only it was pathogen-free, retained water longer and more evenly, didn’t cast
odors, and didn’t present the mold problems that soil seemed to present at
times. Because it was packaged in dry compressed
bricks, it was lighter than soil, took up less storage space, and eliminated
the issue of frozen soil in winter. My
only problem with coco coir was its nutritional value. Sure, it produced a nice looking short grass
for floral use, but could it possibly provide the same nutritional benefits as
soil for my juicing clients? If not, what
did I need to do to bring this growing medium to a place where I could feel
good about selling what I was growing to customers who valued product nutrition
above all else?
First of all, let’s look at the nutritional needs of the
wheat berry as it sprouts, produces shoots, and becomes the grass that is
eventually harvested. Seeds generally do
not require any nutritional amendments when they are just sprouting. That is true of wheat berries as much as it
is true of any other seed. The nutrition
a seed requires to sprout into a baby green essentially comes from the seed
itself. It’s when a plant’s second set
of leaves begin to emerge that it depends on its growing medium as a lifeline. At that point, all conscientious growers,
whether they grow in soil, coco coir, water, or anything else, take measures to
ensure that their growing medium is equipped to support the nutritional
requirements of the plant.
After a great deal of experimentation, I have found that
wheatgrass does fine in coco coir up until it is time to harvest and pretty much not a moment more. Sure, the entire tray doesn’t yellow all at
once because not every single wheat berry sprouts at exactly the same time, but
the moment each little shoot begins to require more nutrition for its next
level of maturity (when the grass begins to form another blade), it no longer
has what it needs to thrive in coco coir alone and begins to yellow, much more
dramatically than when the grass is grown in soil. This predictable yellowing tells me that I am
working with some sort of nutritional deficiency in the growing medium and that
nutritional supplementation is required.
So, let us look at what types of nutrients coco coir has to
offer, what types of nutrients wheat requires, and what our options are in
terms of healthy organic supplemention to help get us to where we need to be on
a nutritional level and feel good about our hydroponically-grown grass in a way
that we have come to feel good about our soil-grown grass.
pH. First and foremost, let’s look at pH. Exceedingly important to keep that right. Without the proper soil/water pH, everything else goes out the window. Wheat grows best at a pH between 6.0 and 7.0, which is slightly acid. I have personally found that it grows best somewhere around 6.5. As mentioned in one of my previous articles, the slight soil acidity enables the plant to process all of the required micro and macronutrients most efficiently. I realize that is tough concept to swallow for some folks who are looking to alkalize their bodies using wheatgrass, but trust me on this one: soil alkalinity does not equal body alkalinity. At least not here. So if you are growing in soil, this means testing your soil supply periodically with a soil testing kit, and also testing your water with the proper metering device to make sure that you are not flooding your wheatgrass everyday with something that is either too acid or alkaline for your grass.
pH. First and foremost, let’s look at pH. Exceedingly important to keep that right. Without the proper soil/water pH, everything else goes out the window. Wheat grows best at a pH between 6.0 and 7.0, which is slightly acid. I have personally found that it grows best somewhere around 6.5. As mentioned in one of my previous articles, the slight soil acidity enables the plant to process all of the required micro and macronutrients most efficiently. I realize that is tough concept to swallow for some folks who are looking to alkalize their bodies using wheatgrass, but trust me on this one: soil alkalinity does not equal body alkalinity. At least not here. So if you are growing in soil, this means testing your soil supply periodically with a soil testing kit, and also testing your water with the proper metering device to make sure that you are not flooding your wheatgrass everyday with something that is either too acid or alkaline for your grass.
Coco coir itself does not need to be measured with a soil
tester. Its pH is pretty stable at the
correct level, between 6.0 and 6.5 straight out of the bag. It’s when you add that 7:1 ratio of water to your
coco coir that everything has the potential to change, so having a meter that
measures water pH is extremely important for hydroponic growers as well. I cannot stress that enough. My water tends to be very alkaline, close to
8.0, so I add a little bit of citric acid to my water bath before soaking the
coco coir. It only takes a tiny bit to
dramatically change the water pH. Citric
acid is naturally derived from citrus fruits and provides a short-term
correction to an alkaline growing medium.
For a short-term crop like wheatgrass, citric acid works perfectly.
Macronutrients. Next, let’s look at the macronutrients. All plants need Nitrogen (N), Phosphorus (P),
and Potassium (K) to survive, each in varying quantities depending on the
plant. For wheat, higher levels of
Potassium are desired by farmers for higher protein content in the grain, but
that potassium uptake is not even a factor until the heading stage, and it is
irrelevant for the purposes of harvesting wheatgrass. Because wheatgrass is harvested as a baby
green, technically halfway through its first stage of growth, it does not
require heavy fertilization. Suffice it
to say, unless your soil is entirely deficient in one of the three
macronutrients, your wheatgrass should be just fine, but the only way to know
exactly what you are working with is with a soil testing kit. A simple soil testing kit to tell you if your
NPK ranges are high, medium or low is all you really need as a home grower. A low reading on any of the three
macronutrients calls for some sort of soil amendment to bring things into
balance (see Simple
Soil Chemistry and Organic Amendments for Your Wheatgrass Crop).
Coco coir, on the other hand, is a given. It is naturally high in Potassium, with lower
levels of Nitrogen and Phosphorous, which means that the type of natural
amendment we are looking for is one that provides Nitrogen (to help give a
plant its proper green) and Phosphorous (for strong young root growth) but not
as much Potassium (which, in excess, can actually inhibit nitrogen levels). What I have found to work best for my needs is
the addition of spent coffee grounds to my coco coir mix, which gives a nice
Nitrogen boost (solving the problem of yellow grass) and helps increase
Phosphorous for strong root growth without also increasing Potassium too much. With the coco coir, I like to keep my
amendments plant-based as this presents more immediately bioavailable nutrition
for the roots of my short-term crop. Coffee
grounds do not seem to present composting issues that can damage a baby crop,
and contrary to popular belief, spent coffee grounds are not high in acid. The pH of spent coffee grounds measures with
some variability in the 6.0 range, which is exactly where we want to be with
wheatgrass. If you choose to use spent
coffee grounds, be sure to refrigerate them until use.
Micronutrients. Coco coir,
while not a micronutrient powerhouse, actually does carry with it an array of low-level
micronutrients, including iron, magnesium, copper, and boron. It is not enough to really make a substantial
difference in a maturing crop, however, so it is probably a good idea to
supplement coco coir with a nice liquid organic fertilizer packed with
micronutrients, like liquid kelp, which is immediately bioavailable to the
roots of our short-term wheatgrass crop and can easily be added to the coir’s initial
water bath. Remember that wheatgrass
does not require a whole lot though, so pour judiciously. Remember, you just need enough to carry you
through those last couple of days before harvest. Liquid kelp, while lacking in macronutrients,
provides an ample supply of micronutrients, trace minerals, amino acids, and
natural plant hormones to help stimulate growth and produce a nutritious baby
green. Even folks who prefer to grow in
soil find liquid kelp to be a wonderful soil amendment.
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In summary, coco coir offers growers a sustainable growing medium that
is pretty stable from package to package in terms of pH and nutrient
analysis, making crop planning more controllable and predictable. Soil,
on the other hand, can vary greatly depending on its source and needs to
be tested with a soil tester and amended accordingly. Whether growing
in soil or coco coir, water pH is a major factor. A device for measuring
water pH is a must for any grower. If growing regularly within confined
indoor growing areas year-round, coco coir offers many benefits in
terms of cleanliness and storage. If growing in a greenhouse or
outdoors, soil offers a more complex and often-preferred nutrient
base as well as that certain intangible "earth connection." It also
offers cost efficiency. Coco coir, unfortunately, requires a fair bit of
price shopping and is still slightly more expensive than bagged soil (tray for tray). The price of
coco coir has come down considerably in recent years, however, and will
probably equal that of bagged soil as demand continues to increase. It
also offers the look and feel of soil for those who are just more
comfortable growing in soil.
As a consumer, you should be aware that hydroponically-grown
fruits and vegetables have been shown to nutritionally out-perform their
soil-grown counterparts in European studies.
In America, the USDA has
determined there to be no nutritional difference between the two growing
methods.
As to how you should grow and what you should consume, it’s
all a matter of what is practical for the grower and what is preferred by the
consumer. The better method, it appears, depends on the situation.
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