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How to Make Money Growing Marijuana

Updated: Mar 25, 2023

Growing marijuana in your own home is legal in 21 states and counting. As the legalization movement progresses, marijuana cultivation is becoming more socially acceptable every day. In addition, people are beginning to realize that growing marijuana can be a legitimate source of extra income.


Some people who read this article may reside in states or countries where growing marijuana remains illegal. If you're unsure whether or not you live in a state where it is legal to grow marijuana, please visit the Marijuana Policy Project to find out or consult the map below.

Legal for recreational use

Legal for medical use


"D" = Decriminalized

That being said, this article does not encourage anyone to break the law. We ask that all of our readers abide by their local laws, including marijuana laws, and we provide the following information for entertainment purposes only.

Table of Contents

Basic Marijuana Horticulture

Any who tells you that growing marijuana is easy has likely never done it. Marijuana growing requires patience, hard work, financial management, and the ability to solve problems proactively.

It's not rocket science, but there is still quite a bit of information to digest.

Let's start by defining a few basic terms:

It all starts with the cannabis plant.

If you had a handful of natural cannabis seeds, scattered them into the ground, and allowed them to grow freely, the male plants would pollinate the female plants, and the resulting crop would be industrial hemp.

Industrial hemp is renowned for being a strong and versatile natural fiber that can be woven into rope, cloth, etc...

Industrial hemp growing naturally
Industrial hemp growing naturally

Although industrial hemp does contain trace amounts of THC, (the psychoactive organic chemical compound for which marijuana is famous), there's not enough THC in industrial hemp to get you "high."

Instead, industrial hemp produces flowers full of seeds, thus ensuring the plant species survival.

However, if you were to isolate that same group of cannabis plants and remove the male plants, the female plants wouldn't be able to receive pollen.

Female cannabis plants growing in isolation
Female cannabis plants growing in isolation

This scenario triggers an 'evolutionary panic' within the female cannabis plants, which begin producing large, colorful, smelly, resinous flowers to attract insects carrying pollen so they can produce seeds and live another year.

Alas, the pollen never comes.

When these flowers have reached the peak of resin production, they are harvested, dried, and trimmed of the leaves so that only the resin-laden bud of the flower remains.

These "buds" are then dried, cured, and enjoyed; and are colloquially referred to as marijuana.

"Marijuana" is the unpollinated flower of the female cannabis plant
"Marijuana" is the unpollinated flower of the female cannabis plant

To recap:

  • Cannabis - The plant from which both industrial hemp and marijuana are derived

  • Industrial Hemp - The result of allowing cannabis plants to self-pollenate and grow freely

  • Marijuana - The dried & trimmed flowers of unpollinated female cannabis plants.

Now let's examine the five most basic needs of the cannabis plant.

The Five Pillars of Growing Marijuana

Marijuana growers will often describe the cannabis plant as a wooden barrel, with each stave representing a different requirement for growth.

Each requirement for marijuana growth is as important as staves are to a barrel

The barrel can only hold water if all the staves run the entire length of the barrel. If one stave were missing or was shorter than the others, it would single-handedly limit the amount of water the barrel would only be able to hold.

Marijuana is similar because your plant is only as healthy as its most lacking requirement for growth.

Each has a role to play, and they are all indispensable. Let's look at them one at a time.


Plants use light energy to rearrange the molecules in water and carbon dioxide to make glucose, which plants then use to perform a wide variety of metabolic functions. This process is called photosynthesis, and it doesn't work without light.

Light can be measured in two different ways - quantity and energy.

The quantity of light your plants receive is determined by the brightness of your lights, which is measured in lumens or Lux (1 Lux = 0.093 Lumens.)

A lumen is equivalent to the light that one candle casts into one square foot of space.

The closer your plants are to their light source, the more lumens or Lux they receive.

Cannabis requires a minimum of around 600 Lux, which can easily be achieved using fluorescent or incandescent light bulbs (2900 lumens).

There's no upper limit to the amount of light cannabis can receive. Cannabis plants thrive in natural sunlight, which can be as bright as 100,000 Lux, depending on your geographical location.

Most marijuana growers use 1000-watt High-Pressure Sodium bulbs to provide their plants with as much light as technology will allow. However, even these colossal light bulbs will only emit around 10,000 to 13,000 Lux.

This disparity puts greenhouse growers at a distinct advantage over indoor growers.

The other way to measure light is energy, which we measure in watts per square meter.

Energy describes the light's ability to do work (i.e., drive photosynthesis) and depends mainly on color, which is a function of wavelength, measured in nanometers (nm).

The longer the wavelength, the more energy the light contains.

Depending on the light color, different amounts of energy are required to produce the same amount of lumens.

Light color is measured in degrees Kelvin (k).

Red and blue wavelengths (4400k - 7200k) are optimal for marijuana growing.

The above chart illustrates the differences between red and blue light; and their respective temperatures. "Cool blue" light is the closest to natural sunlight.


Cannabis is a weed (literally), and it can tolerate water stress reasonably well. However, growing high-quality marijuana requires a reliable source of clean water.

Outdoor growers tend to have the most success in areas of the world that receive around 970mm of rainfall per year, although the acceptable range spans from 310mm/year to 4030mm/year.

In any case, growth peaks when soil saturation reaches around 80%.

Plant hydration is expressed as water potential and is measured in MegaPascals (MPs) or bars.

Water also plays a significant role in plant nutrition.

Aside from physically transporting nutrients to the root system, the pH of the water that your plants receive determines which nutrients are available to your plant.

Nutrient availability chart
Cannabis grows best in slightly acid soil

The pH (parts hydrogen) is a measurement of the free hydrogen and hydroxyl ions in your water, and it expresses the acidity or alkalinity of your water.

We measure pH on a scale of 0-14 with 0 being highly acidic, 14 being highly basic, and 7 being neutral.

The EC (electrical conductivity) of your water measures the amount of total dissolved solids (TDS) that your water contains and is expressed as parts per million (ppm).

Young plants (clones & seedlings) should receive water that measures around 200 ppm. Late-stage vegetative plants should receive up to 600 ppm, and flowering plants can tolerate up to 1,200 ppm.

Keep n mind that these numbers are just general guidelines. Larger plants require more nutrients, and plants that grow under natural sunlight will drink faster than plants under artificial lights.


Carbon dioxide is a critical component of photosynthesis and is often the primary constraint for optimal plant growth.

Professional indoor growers will often enrich their grow spaces with supplemental carbon dioxide to increase the rate of photosynthesis.

Indoor cannabis plants receiving supplemental CO2
Indoor cannabis plants receiving supplemental CO2

However, this can be difficult to achieve.

It's far more practical to simply draw fresh air into your garden from the outdoors.

Our air presently contains about 300-400 ppm of carbon dioxide, although some urban areas may be as high as 600-900 ppm.

To achieve optimal growth, ensure you have enough ventilation (fan power) to completely cycle in the air inside your grow space every 5 minutes.

You should also make sure that you have a low-speed fan inside your grow room to circulate the air and help your plants absorb more carbon dioxide.

Fans circulating air above flowering cannabis plants
Fans circulating air above flowering cannabis plants

However, if you do decide to supplement your grow space, be mindful of your technological limits.

Plants require light in order to metabolize carbon dioxide, and 1000-watt bulbs only allow the plant to utilize carbon dioxide up to about 1000 ppm. Anything higher than that is wasted under indoor lighting.

Outdoor growers can provide their plants with additional carbon dioxide by positioning their compost heaps upwind from their gardens.

Compost heaps help supplement CO2 outdoors
Compost heaps help supplement CO2 outdoors

In addition to carbon dioxide, oxygen also plays a vital role in plant health.

The root zone (rhizosphere) contains millions of microbes that depend on oxygen to live, and they breathe by reclaiming oxygen molecules dissolved in water.

That's why it is critical that all feeding water be aerated.

You can accomplish this by keeping the water circulating within a reservoir or by placing an air stone in the reservoir and constantly pumping air through it.

Water being aerated
Water being aerated

If you plan on supplementing your garden with carbon dioxide, keep your reservoirs in a separate space to prevent carbon dioxide from displacing the oxygen in your water.

Soil & Nutrients

There are three main components of soil: sand, silt, and clay.

These components differ in size and texture, which translates into varying abilities of soil to drain and/or retain water.

USDA Textural Soil Classifications
USDA Textural Soil Classifications

Sand is the biggest of the three components (0.5mm - 2mm) and has the consistency of fine gravel.

Silt is slightly smaller (0.002mm - 0.5mm) and has a powdery texture.

Clay is the smallest of the three components (>0.002mm) and has a sticky feel.

The smaller the particle, the greater the ability to hold water. In other words: Sand helps soil drain, and clay helps soil retain water.

The optimal combination of all three soil components is called loam.

Loam drains well but also retains organic matter, allowing for maximum nutrient uptake.


Cannabis requires large amounts of 6 particular elements.

We call these elements macronutrients, and they include Nitrogen (N), Phosphorus (P), Potassium (K), Sulphur (S), Calcium (Ca), and Magnesium (Mg).

Nitrogen plays a major role in the physical development of plants.

Phosphorus supplies energy to fuel metabolic reactions within the plant.

Potassium and Calcium bond with other nutrients and escort them through the cell wall.

Sulfur is an essential component of amino acids, enzymes, and vitamins and helps to promote healthy microbial growth.

Magnesium is the basis of chlorophyll.


In addition to macronutrients, plants also require small amounts of other elements. These elements aren't necessarily utilized by the plant but fulfill various other functions related to soil health.

These elements are called micronutrients, and they include; Iron (Fe), Zinc (Zn), Boron (B), Copper (Cu), Manganese (Mn), Chlorine (Cl), and Molybdenum (Mo).

Large quantities of micronutrients are toxic to plants.


Environmental factors include temperature, humidity, and air quality.

Plants require specific environmental conditions to survive, and cannabis is no different. However, the cannabis plant is particularly hardy and durable compared to other plant species.

After all, it is a weed.

We will be reviewing environmental factors that are ideal for optimal growth.

Yes, deviating beyond the optimal range for temperature and humidity is bad; and yes, failure to maintain proper environmental conditions will negatively impact your overall yields and make your plants more susceptible to pests, molds, and diseases; but environmental factors would have to be well beyond the optimal ranges for a significant period of time to actually kill your plant.

In any case, high-quality marijuana requires ideal environmental conditions.


Temperature control is indispensable in cannabis cultivation. The optimal range for flowering cannabis plants is between 72-76 degrees Fahrenheit during the day and anywhere between 5-10 degrees cooler at night.

If the temperature difference between night and day exceeds 15 degrees Fahrenheit, it will encourage mold growth.

Temperatures in excess of 85 degrees Fahrenheit will cause photosynthesis to slow down and ultimately diminish your yield and quality.

The lower end of the acceptable spectrum is 57 degrees Fahrenheit.

Plants in the vegetative stage thrive in slightly higher temperatures (74-78 degrees F), and rooting clones should be kept even warmer (78-82 degrees F).

Hydroponic gardeners also need to consider the temperature of their water.

The colder water is, the more oxygen it is able to hold.

As the temperature of water rises, the water becomes less able to hold oxygen, and plant roots become susceptible to fungus, which ultimately inhibits nutrient uptake and kills the plant.

If you plan to grow hydroponically, I highly recommend a water chiller to keep your temperature at a constant 42 degrees Fahrenheit.


Like temperature, there are different optimal humidity ranges for different phases of growth.

Flowering plants prefer dryer air with 40% - 60% RH (relative humidity.)

Vegetative plants can tolerate between 40% - 80% RH.

Rooting clones require a minimum of 60% at all times but will do better in 90% - 100% RH for the first 48 hours and then 80% - 85% RH until they are fully rooted.

When drying your harvest, it's important to keep the humidity between 40% and 50% to aid with the curing process and preserve flavor.

How to Start Growing Marijuana

Now that we have a better understanding of what marijuana requires let's take a closer look at the plant itself.

Stages of Growth

Plants have 5 generally accepted phases of growth: Germination, seedling, vegetative, flowering, and ripening. For the purposes of this guide, I'm going to add a 6th phase: Harvest.

If you plant to grow from seed, pay attention. It's critical that you understand these first two phases. Anyone planning to grow from clones can skip ahead to Vegetative Growth.


Seeds can last for thousands of years if they are preserved properly. However, if they are subjected to the right combination of heat, moisture, and air, they will begin to germinate.

Germination takes place entirely in the dark and occurs when environmental conditions allow hormones within the seed (cytokinins, auxins, and gibberellins) to activate.

Cells begin reproducing and increasing in size until they break through the seed's tough outer shell.

Germination illustrated
Germination illustrated

A single taproot will extend downward in search of water, and when that taproot successfully locates a source of water, a sprout with tiny leaves will begin growing toward its most-dominant light source.

You can germinate seeds by placing them between two paper towels that have been wet with distilled water. Sandwich the seeds gently between the paper towels and then place the paper towels with the seeds between them onto a dinner plate.

Cover the plate by placing another plate of equal size upside down on top of the first plate, and then place the entire ensemble on a heating pad that has been set to "Low."

Keep the paper towels moist, and you should see taproots emerge after 3-5 days.


The taproot continues growing downward and begins branching out.

It should be noted that only half of a plant exists above the soil line and that the root structure of a plant is a subterranean mirror image of the branches.

This correlation exists in every phase of plant growth.

As the roots continue to grow, they begin to anchor the plant to the ground and allow for more and more leaf & stem development.

Leaves allow the plant to absorb light, which is necessary for photosynthesis.

More leaves mean faster growth, so it's a good idea to give your plant 24 hours of soft, blue light (4400K - 5600K) at this stage, although 16-18 hours of light will still be sufficient.

T5 fluorescent bulbs are ideal for this task.

Vegetative Growth

Plants need at least 16 hours per day of light to maintain vegetative growth, although most growers choose to give their plants a full 24 hours of light during this stage to maximize growth.

Again, blue light is ideal for this stage of growth and plays a vital role in critical metabolic processes that occur during vegetative growth.

Cannabis plants in the vegetative growth phase
Cannabis plants in the vegetative growth phase