How to Grow Marijuana
Marijuana seeds & more
THE INDOOR
GROWING ENVIRONMENT
THERE ARE MANY WAYS to grow cannabis plants indoors.The two core methods
are soil growing and hydroponics. Chapter 9 is dedicated to hydroponics.
The next three Chapters deal with soil growing: from basic setups, to
controlling the environment, tending your plants throughout the life cycle
and advanced techniques. Although these Chapters focus on indoor soil
grow, the hints and tips provided can be used to improve plant health
and growth in any growing marijuana environment.
There are many ways to grow an indoor soil garden ranging from basic
setups to advanced setups. The most common indoor basic setups are:
• Soil growing -,
• Hydroponic growing
The most common advanced indoor setups are:
• SOG growing
• ScrOG growing
• Cabinet growing
Hydroponic cannabis growing is covered in Chapter 9.The common advanced indoor
setups are discussed in detail in Chapter 8. First we will look at what
all indoor growing marijuana etups nave in common.
LIGHTING
Your choice of lighting is the second most important growing decision
you will make next to selecting your strain. Lights come in all shapes
and sizes with varying levels of wattage and lumens. A full indoor lighting
kit should contain the following items: bulb, reflector, ballast, timer
and electrical inputs/outputs.
Most lighting kits are open, meaning they have no glass cover or hood
to shield the bulb. Instead, the bulb is fixed into a socket that is attached
to the inside of the reflector and hangs directly underneath the reflector.
That socket is in turn connected to the ballast, which can be either internal
or external.* If external, there will be a cord leading to the ballast
from the bulb's socket. If internal, the ballast will be attached directly
to the bulb socket and may even support the reflector. The ballast plugs
into a domestic light socket like the ones in your home. Some ballasts
have built-in timers.
When purchasing a lighting system it is recommended that you look for
a complete system and buy an extra bulb. Check to make sure that the lighting
system meets safety regulations and has some sort of guarantee or warranty.
Color Bands and Plant Growth
When a beam of light is split by means of a prism or diffraction grating,
it produces a number of color bands which represent the colors of the
rainbow: red, orange, yellow, green, blue, indigo and violet. The bands
correspond to the frequencies emitted by the heated light source.
The electromagnetic spectrum is a term used to describe the distribution
of electromagnetic radiation by reference to energy. The table below roughly
gives wavelengths, frequencies and energies for different regions of the
spectrum. You may want to refer back to these later if you are interested
in analyzing your bulb's qualities. On the bulb's packaging you should
be given data on the bulb's use of the electromagnetic spectrum. Your
bulb should mention wavelengths and frequencies somewhere between the
'Infrared', ^Visible' and 'Ultraviolet' regions. Each bulb manufacturer
has different specifications with regards to the bulb's abilities to cast
artificial light.
Light color depends on the light source. It also is a visual indicator
that a number of different factors important to plant growth are present
in the light. Artificial grow lights are designed to provide an intense
and clean white light that meets certain color and temperature requirements
so that the bulb can be classified as a 'grow bulb'.
The Correlated Color Temperature (CCT), the thermal temperature, of a
light source is usually expressed in degrees Kelvin (K). When certain
basic elements that are used in light bulbs are heated, they start to
glow. As the elements get hotter, they change color. This occurs within
a certain range and peaks when the bulb is fully heated. At this peak
the color holds and this is the CCT rating of the bulb. Bulbs that have
a CCT rating of 3000 are referred to as 'warm' bulbs. A CCT rating of
4000 is a'neutral'bulb and a 6000 CCT bulb is a'cool'bulb. The color of
the bulb at CCT is a combination of the many different colors being emitted
by the hot elements in the bulb.
Although the CCT gives us an indication of the bulb's color temperature
it does not tell us much about how well each of the color bands are represented.
For this we need to refer to the lamp's Color Rendering Index (CRD.This
is done under laboratory conditions by comparing the bulb's CCT with a
darker material at the same CCT. It is generally understood by the growing
community that the higher the CRI rating of a bulb, the better the quality
of color distribution.
Outside daylight measures around 5500K for most of the daylight hours.
The next table shows the colors you will come across most often when using
artificial light sources and the effect that each one has on growing cannabis
plant growth.
IMPACT OF LIGHT COLOR ON PLANT GROWTH CCT in Kelvin (K) Light Color Effect
5000 to 8000 Deep blue Encourages excellent leaf and stem growth 4000
to 5000 Light blue Encourages good leaf and stem growth 4000 Neutral white
Promotes normal growth 3700 to 4000 Warm neutral Promotes rapid growth
3000 to 3700 Warmer yellow neutral Highly active photosynthesis for all
stages
of growth 1500 to 3000 Hot orange or red Promotes flowering
Plants are green, which means they reflect green light. This is due to
fact that cannabis growing, and most other plants, does not use green light for
photosynthesis. This has to do with chlorophyll. High intensity discharge
(HID) bulbs are designed to cast as much useable light as possible.There
are two different types of HID grow lights that we will discuss in a moment.
Each type is designed to lean towards casting a warm or a cool type of
light. HID grow lights are the most common type of indoor lighting used
for growing cannabis.
Basics of Photosynthesis
It is important for us to understand the basics of photosynthesis because
it is at the heart of the cannabis plant's energy system. Plants are the
only organism with the biological ability to synthesize complex foods
for themselves from simple substances.
Chlorophyll
Plants naturally produce chlorophyll, which gives them their green color.
Chlorophyll is a group of magnesium-containing green pigments that act
as an absorber of light energy for specific wavelengths. The plant converts
this light energy into chemical energy.
++The Process of Photosynthesis
Photosynthesis means 'combining with light'. Photosynthesis is a Veactant
- product' process which occurs wherever chlorophyll is found in the plant,
which is mostly in the leaves. The symbolic equation for photosynthesis
is:
6 C02 + 6 HzO -sunlight &. chlorophyll -C6H1Z06 + 602
If there is no light then there is no photosynthesis. At night plants
cease photosynthesis. If there is not enough nutrients then chlorophyll
will not be produced by the plant and photosynthesis will cease. Temperatures
are also important for photosynthesis. If the temperatures go out of the
normal range for good cannabis growing then photosynthesis will slow
down or even stop. See Chapter 6 for more on temperatures.
Common Lighting Types
Domestic Lights
These are the lights you find in use around your house.They come in all
sizes and
generally range from between 15 and 150 watts. These lights are unsuitable
for
growing because of their low light intensity and poor CRI rating. Standard
domestic bulbs have a CCT rating of about 2700 K.
Fluorescent Tube Lights
These lights are the long, tube-shaped, lights commonly used in industrial
and commercial buildings. They come in a variety of lengths and sizes,
but 2 to 10 foot-long bulbs are the most common. They also range from
between 10 and 300 watts. These lights are okay for growing but they provide
a low light intensity and are difficult to set up properly. They are also
not in the best light spectrum for the growing cannabis plants because,
like domestic lights, fluorescent tubes have poor CRI ratings.
Halogen Lights
Halogen lights are small and often used for flood lighting during the
night. These lights can range from anywhere between 75 and 4000 watts.
Halogens get extremely hot and this creates a completely unsuitable condition
for growing marijuana.They are not recommended because they can be dangerous
for indoor growing use. They also have a low CRI rating. Halogens have
a CCT rating^of about 3000 K.
Fluorescent White Tube Lights
Similar to fluorescent lights, fluorescent white tube* lights have a higher
CRI rating. These lights do not range high above 100 watts and are only
recommended as 'cheap to buy and run' grow bulbs. They can, however, be
invaluable for rooting clones and starting seeds. Fluorescent white tube
lights are usually found in the following wattage levels — 10W,
30W, 60W and 100W. You should aim for 30W and above if you want to induce
some form of floral development. Less than 30W lights are only sufficient
for rooting cuttings and starting seedlings. Cool white fluorescents have
a CCT rating of about 4200 K.
Horticultural Lights
Commonly called HID (high intensity discharge) lights, professional horticultural
lights are designed to promote indoor plant growth. These lights are available
in kits complete with bulb, reflector, ballast and timer. They also come
in different wattage levels, shapes and sizes. If you want to grow good
bud, you should use HID lighting. HID lights have three distinct subcategories:
metal halide (MH), mercury vapor (MV) and high-pressure sodium (HPS).
Metal Halide <MH) and Mercury Vapor (MV) Lights MH lights are HID
lights that are used for the seedling and vegetative growth stages of
your plant.They can also be used for flowering. They come in all shapes
and sizes and range from 75 to 4000 watts. These lights are very commonly
used kits and are ideal for indoor marijuana growing. M H lights mostly
lean towards a blue color meaning that the bulb is a vcool' type. Daylight
MH lights have a CCT rating of about 5500 K. Standard clear MH lights
have a CCT rating of about 4000 K. 'Warm' MH lights also exist and have
a CCT rating of about 3200 K. Opt for the daylight halide, as it provides
the best possible type of MH light for marijuana growing.
MV lights have been almost replaced by MH lights. If you have a choice
between the two it is best to opt for the newer MH kits. MV has a tendency
to be slightly out of the optimal spectrum range, being too blue.
High-Pressure Sodium (HPS) Lights
HPS is the lighting choice of many a cannabis cultivator. HPS lights come
in all shapes and sizes and range from 75 to 4000 watts.They are in the
perfect spectrum for growing cannabis and come highly recommended, particularly
for the flowering stage of the life cycle. HPS lights lean towards a blue
color meaning that the bulb is a 'warm' type. High-pressure sodium bulbs
have a CCT rating of about 2200 K.
Wattage and Lumens
HID lights can range from anywhere between 75 and 4000 watts." In
general, the stronger the wattage the more light that bulb will produce.
However, we must also consider another factor called lumens. Lumens are
the correct way of measuring how much light per square foot a bulb emits.
Lumens and wattage go hand in hand, but can vary to a large extent between
systems. In general, the better the lighting kit, the more lumens it will
cast. Lumens have more to do with the design of the light than the wattage
of the light itself. Some 600-watt lights may emit the same lumens as
a 400-watt light. The sample comparison table below shows the lumens emitted
by four different lamps. Of note, the two HPS lamps both use the same
wattage, but cast different levels of lumens.
Lumens and Marijuana Growing
You are probably wondering: How many lumens do I need? This depends on
three
things:
1. How much you want to spend
2. How many plants you have
3. The size of your grow area
You never want to use less than 2500 lumens, even for one plant. In general,
one light that casts 45,000 lumens is enough to cover a grow space of
about 3 feet by 3 feet.This is quite an average space and you'll probably
get anything between 1 to 12 Indica plants in that area. Again we must
keep in mind the strain that we're growing. One large Sativa plant can
cover a nine square foot grow area in no time. Short Indica plants are
different. If you really want to pump up your plants, then you could consider
a lamp that casts 100,000 lumens or more. If you have a big grow area
then you might consider two lamps that cast 100,000 lumens each. It's
all relative to how much you want to grow and the size of your grow room.
Let's say that you would like to grow four Indica/Sativa hybrid plants.
What you should aim for is a light that casts 45,000 lumens. This means
you should buy a 600-watt HID system. If you want to pump up your available
light to around 60,000 lumens, you should buy a 1000-watt HID system.
If your area is bigger still, you might need two or more 1000-watt HID
lights to achieve this.
The General Illumination Formula
You need roughly 50 watts of HPS or MH light per square foot of your grow
area. The simple formula looks like this:
250W HID = 2'x 2'area 400W HID = 3'x 3'area 600W HID = 3.5'x 3.5'area
IkW HID = 4'x 4'area
This simple watts-per-square-foot calculation assumes that each square
foot of space receives the same lumens but in reality bulbs do not cast
lumens equally to all areas of the space. We need to include depth in
our calculation. As light travels away from its source, its intensity
diminishes by a factor of one quarter each time the distance traveled
doubles.
There's nothing wrong with using a 1000-watt HID light on a few plants
or even one plant — they will grow bigger and better for it —
but you need to make sure that you choose genetics that can use all the
available light. Lighting overkill occurs when a single strong HID light
is used to grow a genetically poor yielding plant. You will find that
a single 400-watt HID may have been more than enough to grow the plant
to optimal maturity. Most strains available from reputable breeders are
high-yielding plants, which is why growers can sometimes use a single
1000-watt light and pull sometimes two pounds or more of bud from the
one plant.
The other issue is cost. Do you really want to spend all that money on
lighting and electricity? HID lights range in price from anywhere between
$220 and $700 for a full kit. A faOO-watt H PS kit should cost about $250:
money well spent if you want great plants with big buds.
Over time you will understand more about grow rooms and how to light
them properly. With experience you should be able to tell intuitively
which light suits your needs. As a general rule, when in doubt buy a 400-watt
H PS or better. Even a 250-watt H PS can get you good-size buds, but going
below that mark will yield you less than average results. Most growers
use a 600-watt HPS for better results. 1000-watt lights provide the best
yields indoors but consume more electricity.
What to Look for When Buying a Lighting Kit
What type(s) of HID/horticultural light will you use? Some growers will
use a
M H setup for seedlings and vegetative growth and a H PS setup for flowering.
If
you can only afford one setup, we recommend HPS lighting since it is best
for
flowering — the stage when cannabis produces the all-important bud.
Is the light kit certified; does it come with a warranty? For obvious
reasons.
Is the light kit air-cooled?
Water-cooled light system — these inventions have been around for
a while but have not caught on because they require a bit of work to maintain.
A constant pump of cool water must be circulated into and out of the light
system.
Good lights should be air-cooled. Some may even have built-in fans. Lights
that are air-cooled tend to last longer and do not heat up your grow area
as much. If your light is not air-cooled then you will have to include
an air vent and fan in your grow room to keep the temperatures under control.
Remember that your plants can burn if placed too close to your lights.
How will the system be supported? Will you use a light stand or suspend
your lighting from the ceiling?
Do the electrical fittings suit your needs? Will they plug straight into
your system or will you need an adapter or an extension cord?What wattage
and lumens can you use with the kit?
Most HID kits can only accommodate a specific wattage of bulb and a certain
type of bulb. If you have a 600-watt H PS system, then you should only
use 600-watt HPS bulbs. Some lighting kits include a switchable ballast.This
means that you can use both MH and HPS lights with the system.
Also, there is such a thing as too much power. A 4000-watt HID is overkill
for any small grow room. A 1000-watt bulb is the maximum wattage you should
purchase for a small space. Use several 1000-watt bulbs if you need more
light. A 4000-watt bulb can bleach cannabis and is very hot.
How to Get the Most from Your Lighting System
Reflectors do exactly what their name implies — they reflect light.
Growers use reflectors to ensure maximum lumens coverage over their plants.
Basically, when light bounces off a reflector it is directed towards your
plants, which absorb most of this light. Reflectors should be either white
or made of polished metal. Some reflectors have a green plastic film covering
the insides. Remove this, if possible.
Some grow guides mention Aluminum foil as a useful material to aid grow
room reflection. Some have even mentioned using it to cover up anything
that isn't reflective like electrical cords, sockets, reflectors and pots.
Aluminum foil is actually a very poor reflector, highly heat conductive
and very dangerous to use in a grow room. Aluminum foil only has 30 to
60 percent reflectivity at best, raises the temperature of the item it
is used on (the reflector, pot lid, electrical cord, wall etc.), and can
burn easily. Avoid using aluminum foil. It is also hard to keep clean
and tears easily. Growers who line the walls with Aluminum foil will eventually
find the place falling down around them. If you have no option but to
use aluminum foil then it is suggested that you use the dull side rather
than the shiny side. In the meantime, make sure that you place an order
for a cheap can of flat white paint that will give you almost 99 percent
reflectivity for a couple of years.
White-colored material is best for reflecting light: not shiny, glossy
white, just plain matte white. A white wall will reflect more light than
a mirror or foil. Many growers paint the walls of their grow space white.
Others line their grow areas with Mylar: a substance that looks like a
thick tinfoil sheet. Mylar is, in fact, very popular in cannabis grow
rooms. Most DIY (do-it-yourself) and hardware stores sell Mylar in sheets.
It is also recommended that you keep a spare bulb on hand at all times
in case the other bulb dies.* It's no good going to the local hardware
store only to find that they are out of the bulb you need. You risk leaving
your plants without light for a long time.
It is also wise to remember that plants need water and lights use electricity.
When mixed, these factors can be extremely dangerous. Be safe and wise
and keep your plants and any liquids away from all electrical outlets.
Adjusting Your Lights
If you have a good stand or light support, you should be able to lower
or raise your light to accommodate your plants at various stages of the
life cycle. You should note that the closer your lighting is to the plants,
the more light they will receive. However, get too close and you risk
burning your leaves. To see if you are too close, try this simple, common
sense test: if you can hold your hand under the light and not feel discomfort,
then your plants should do okay. If you feel discomfort, so too will your
plants. Use common sense and adjust your lights accordingly.
Some cannabis plants can grow as much as an inch a day. Pure Sativa varieties
in particular can triple in height between the start and end of flowering.
A four-foot Sativa bush can suddenly turn into a twelve-foot monster in
a few months. You need to monitor growth carefully to ensure that your
plant doesn't get too close to the light. If your plants do suffer a burn,
use clippers to remove the burnt areas and either adjust your lights or
cut back your plants to maintain a safe, healthy distance. Tying your
plants back may be another option if you have outgrown your space and
don't want to clip the plants because of flowering.
Your plants need all the light they can get during the vegetative growth
stage. Leave your lights on 24 hours a day and enjoy watching your plants
as they grow. During the flowering stage you will shift to the 12/12 light
cycle, which is discussed in detail in Chapter 7.
24/0 and 18/6 - The Vegetative Photoperiod
Cannabis is a light demanding plant. Professional growers keep the light
on their plants using the 24/0 photoperiod for this reason. Plants that
grow under 24/0 flourish and do not need a quantity of darkness in order
to rest and perform photosynthesis properly. Plants that are grown in
optimal conditions under the 24/0 light regime grow vigorously and the
benefits of a 24/0 photoperiod can be seen actively in the results. More
nodes are formed, more branches are created, leaf numbers increase, the
plant is growing at its finest.
Some growers opt to use 18/6 as their photoperiod. This is an 18 hours
of light, six hours of darkness light regime. Under these conditions the
plant will grow quite naturally but not as vigorously as the 24/0 photoperiod.
The 18/6 photoperiod expels 3/4 the amount of light that a 24/0 photoperiod
does. Although this does not mean that a plant produces 1/4 less leaves,
branches and nodes under the 18/6 photoperiod, it certainly does show
the correlation between light and cannabis growth. As we have said already,
cannabis is a light demanding plant. There are no problems associated
with 24/0 and although some have attributed cannabis sexual dysfunction
(the hermaphrodite condition) to the 18/6 photoperiod these problems are
actually the result of heat stress.
A 24/0 photoperiod requires that your grow room temperature be kept well
monitored. The 18/6 option is cheaper to run. You use a quarter less electricity
and this will have an impact on your electricity bill. Also the 18/6 photoperiod
will generally extend the bulb's lifespan. During the 6 hours of darkness
the grow room is allowed to cool down for this period but a well maintained
good grow room setup should not require a cooling down period.
24/0 and 18/6 both share the same problem though. Once you start the
pho-toperiod you should keep it that way especially when the plants near
maturity— the pre-flowering phase. An irregular photoperiod can
cause more males than females to develop. It can also cause sexual dysfunction
to appear.* Whether you choose 24/0 or 18/6 as your vegetative photoperiod
try to keep that photoperiod until your plants are mature enough to express
their sex.
Electrical Costs
Everyone who starts out using indoor grow bulbs will probably ask how
much they cost to run. The answer to this is — it depends on how
much your electrical supply company charge per watt or unit of electricity
used. There are also times in the day when electricity is cheaper or more
expensive to use. In general, one unit of electricity is measured at about
1000-watts per hour. 1000-watts per hour usually works out at about 10
cents but can be cheaper or more expensive than this. Check your electricity
bill for the correct price per unit. So in our example:
IkW x 24 hours - IkW x 0.10 x 24 = $2.40 per day = $16.00 per week or
$67.20 per month.
A four month 1000-watt grow could cost up to $268.00. Average growers
using the right genetics yield about 20 ounces from a IkW single bulb.
Experienced growers can go as high as 40 per IkW bulb. Even though the
cost of electricity may seem high, the end results easily justify the
cost.
SOIL
Soil comes in many types and varieties. As you gain growing experience
you will learn to add various ingredients to your soil in order to improve
plant growth. The cannabis plant will grow long, winding roots into the
soil. These roots absorb water and other minerals from the soil to promote
plant growth. The soil also goes through dry periods when you don't water
your plant or when the plant has absorbed most of the water. During these
dry periods air is allowed to creep between the soil particles, allowing
the roots to breathe.
Please note that you should NEVER bring natural outdoor soil into an indoor
grow space.This is because the soil will contain bugs and pests that could
compromise your grow. Always buy your soil from a gardening shop. Soil
should be the cheapest part of your grow.
There are three main factors to consider when selecting the right soil:
pH, nutrients and composition.
PH
pH measures the levels of acidity and alkalinity in the soil.The pH scale
runs from 1 to 14, with 7 being neutral, 0 very acidic and 14 very alkaline.
Cannabis plants like a neutral pH of 7. When choosing your soil you should
be looking to achieve a pH of 7, (it should be clearly marked on the bag).
Going above or below this mark can create problems for your plant during
growth. Small pH meters can be also bought in most gardening shops and
used to measure and monitor the overall pH of your soil.
Nutrients
The three major plant nutrients, or macronutrients, found in soil are
nitrogen, phosphorous and potassium: NPK, for short. NPK can come in two
forms — either pre-mixed into the soil or as a stand-alone fertilizer
(usually in a bottle). The percentage of each nutrient should be clearly
labeled on the packaging, in the following manner: 20:20:20. This indicates
20 percent l\l, 20 percent P and 20 percent K.The remaining 40 percent
are other elements that make up the soil.This ratio can vary among different
nutrient and soil brands so you need to understand which nutrients cannabis
requires, and in what amounts, during the various stages of the life cycle.
Cannabis plants like high levels of N and moderate level of P and K during
vegetative growth. You should select a soil that that has all three. When
choosing a chemical fertilizer you need a mixture with high N, and P and
K levels that are equal to or lower than N. Any of the following combinations
would be suitable: 12:12:12, 20:20:20,12:6:6, or 18:4:5.The 12:12:12 and
20:20:20 are best.
During flowering, cannabis needs a higher level of P so you should choose
your soil and/or fertilizers accordingly. Since the plants are usually
not transplanted between vegetative growth and flowering, you must plan
to adjust the pH levels for flowering.*
Composition
Ideally, your soil will have a balanced consistency: not too moist, not
too dry.This will allow the roots to absorb the required amounts of both
water and oxygen.The packaging should indicate whether the soil is wet
or dry, and you should aim for a balance between the two. Wet soil will
sometimes cause plant damage by blocking off airflow to the roots. Dry
soil may dry out too quickly, starving your roots of moisture. Try to
find a soil that is loose and feels fine but slightly heavy in your hands.
Do not buy anything that is hard and bulky or soft and weightless. Aim
for the middle ground: a balanced composition using a mix of the soil
types below.
COMMON SOIL TYPES
There are many types of soil mediums available and we will briefly describe
the more common types. Marijuana can be grown in most of these soil types.
We have indicated where potential problems could occur.
Clay
Clay is a stiff, tenacious fine-grained earth consisting of hydrated aluminosili-cates
that become flexible when water is added. Marijuana roots don't really
like clay. Clay can rarely be used on its own to grow cannabis. It is
commonly mixed with other soil types to create a medium suitable for cannabis
growth.
Humus
Humus is the organic constituent of soil, formed by the decomposition
of plant materials, and can be bought in bags at local gardening stores.
Most of these products claim to be free of bugs and other living matter,
but sometimes this is not 100 percent true. Don't be surprised if you
find a worm or green fly in the package. Humus is also sometimes known
as compost, but compost is the final mixture of manure (which is of organic
origin), loam soil and some other mediums, with added organic matter.
Humus is that added organic matter.
Sand and Silts
Sand soils can be pure sand or a mixture of sand and soil. The problem
with sandy soil is that it drains water and minerals out too quickly.
It is a very dry soil and is not suitable for the cannabis grower's needs.
Silt soils are nearly the same as sand soils, except they have a consistency
more like clay and are darker in color. Silts hold nutrients well but
do not hold water very well. Like sands they are prone to quick drainage.
Sands and silts are rarely used on their own to grow cannabis and are
mostly mixed with other soil types.
Loam
Loam tends to be a mix of all of the above. The composition of the mix
should be stated on the bag. In fact, in most cases, normal soil purchased
in shops has humus, sand, silt and clay already mixed in. When you buy
a bag of soil it is nearly always going to be a loam. Loam is a very fertile
soil composed chiefly of clay, sand and humus, and is highly recommended
for your grow.
Perlite and Vermiculite
One type of artificial medium on the market is called perlite. It's a
good medium but doesn't come with any nutrients and generally needs to
be mixed with another soil type, vermiculite is another product that should
be treated the same way. Perlite and vermiculite are also called 'inert'soils
because they do not contain any nutrients. In fact vermiculite is processed
mica — a naturally occurring mineral. Mix them well with soil if
it's your first time using them. Begin with one part substrates for every
four parts of soil. With a bit of experience you should be able to control
the mixture ratios, as high as a 1:1 ratio. Pure vermiculite mixtures
or pure perlite mixtures do not retain moisture very well and thus can
only really be used in pure format as a substrate support for hydroponic
systems, which we will explain in a Chapter 9.
Moss
Sphagnum and peat moss are the two most common moss type substrates that
you will come across on the market. This moss is gathered in bogs and
dried out into green, gray, brown and black masses. It is then compressed
into blocks and is used as a substrate by gardeners for its ability to
absorb and retain nutrients. Moss tends to break down very quickly after
successive watering though, and this may require you to add more moss
to your mix before the end of harvest.
MIXING SOILS AND SOIL RATIOS
There is no perfect soil mix for cannabis plants.This is because all strains
are different. Some cannabis strains prefer lots of nutrients. Others
do not because they burn easily. Obviously a less nutrient holding soil
mixture is preferable for the plants that burn easily. Here is a list
of loam soil mixes to suit different plant needs.
Strains that require high levels of nutrients:
1. I\IPK loam soil (20:20:20)
2. Moss
3. pH up
Mix the soil and moss at a 3:1 ratio. Add pH to balance soil to 7.The
high NPK ratio of the loam and added moss makes this a strong nutrient-retaining
soil mixture.
Strains that require normal levels of nutrients:
1. NPK loam soil (10:10:10)
2. Perlite or vermiculite
Mix the soil and perlite/vermiculite at a 4:1 ratio.The average N PK ratio
of the loam and added perlite makes this a good nutrient-retaining soil
mixture.
Strains that do not require high levels of nutrients:
1. NPK loam soil (5:5:5)
2. Sand
3. Perlite or vermiculite
Mix the soil, sand and perlite/vermiculite at a 1:1:1 ratio.This soil
mix does not hold minerals or water very well.This is good for a plant
that does not need lots of nutrients, however light mixtures like this
do require more frequent watering.
All soil mixtures can be changed to suit your plants' needs. In this section,
we have looked at soils without focusing much on nutrient ratios or how
the nutrients themselves work. Even though the above soil mixtures contain
nutrients, they should never be counted on to feed your plants throughout
the life cycle. To maintain the nutrient balance over time you must add
nutrients to our mix. We will look at this in detail in Chapter 6.
Understanding the NPK Ratio
It is important to understand the NPK ratio that appears on soil packs,
fertilizer packs and nutrient bottles. Consider a soil mixture like the
following:
1. NPK loam soil (20:10:10)
2. Vermiculite
You would mix 4 parts loam to 1 part vermiculite to create a medium for
a plant that needs just above normal amounts of nutrients. Instead of
using a balanced 10:10:10 we have gone for the 20:10:10 because we need
that little bit more nitrogen. 20:10:10 simply stands for 20 percent N,
10 percent P and 10 percent K. If we add them we get 20+10+10, or 40 percent
nutrients. The remaining 60 percent is made up of soil particles, or in
bottle foods, water unless otherwise stated on the packaging.
POTS
Pots come in all shapes and sizes. Marijuana plants are best kept in large
pots (1.5 to 3-gallon pots) because cannabis grows long roots. You are
better off buying a pot that has perforations (holes) at the bottom. Perforated
pots should rest in small dishes (you should be able to buy these at the
same time you purchase your pots). When you water your plants some of
the water may drain down through the soil and come out through the perforations
into the dishes. The dishes should be emptied to avoid water spills if
you add too much water. Keep in mind that water on the floor can also
be an electrical hazard.
Instead of using dishes you could use trays. Trays are more professional,
can hold reserve water that is later soaked up by the roots, but are a
lot harder to empty if you do have a spill. Although perforations do help
to prevent over-watering, you should note that water does leech down some
of the nutrients added to your soil. Over-watering can cost you time,
wasted nutrients, and can even kill your plants.
More advanced growers use pots that don't contain perforations. This is
because experienced growers don't overwater or overfeed their plants.
This is a method known as double potting, which helps create a thicker
stem. During vegetative growth, the bottom of the top pot is cut away
and is placed on top of a fresh pot of soil. Fresh soil is then packed
around the edges to hold the pot in place. The roots grow down into the
bottom pot. Look at the size of the cola in this picture by G1YO!
At this stage, you have the best soil you can get
your hands on. You take a seedling, make the
transplant and fill in the empty areas of the new
pot with more soil. Pat down the top of the soil
lightly and apply a stake if support is needed. Add a small amount of
water to
your pot and place the pot and plant under the light. You'll leave the
light on for
24/0 or 18/6 hours a day and watch as your plants grow over the coming
weeks.
By now, you should know how to set up your grow area and make your security
arrangements. You will have your lighting kit set up to hang down over
your grow area. You will also have some form of light reflection around
your plants to help conserve and direct light. You will have obtained
seeds, germinated them on a tray, and started preparing to transplant
them into larger pots. The larger pots will house the plants throughout
the rest of the life cycle, during which time you will provide the best
medium possible in which your plants will grow. In the next chapter we
will explore how to fine tune aspects of the indoor environment to maximize
your yield and get the most from your plants.
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