Cannabis Cultivation

CAC feature episodes are back after a 2 year hiatus! In our 11th feature production – we dive into the science of the Cannabis lifecycle. We start with looking at the evolutionary history of Cannabis before we switch gears and look at how Cannabis is cultivated, dried and cured. We dive into the science involved in many of the changes Cannabis undergoes in its journey to a consumer’s grinder.

I hope you enjoy our return to feature episodes – I have many more planned!

If you’re curious about Cannabis, visit www.cacpodcast.com and check out more podcast episodes and educational content including courses, books, and more!

Stay curious and take it easy!

Show Notes / Transcription:

“It’s a plant that goes by many names. Some call it hemp. Some call it marijuana. Call it what you will, it’s cannabis. And it’s got a lot of people curious.

But what do you really know about the Cannabis plant and how it makes its way to your grinder? In this episode we will be taking things back to their roots, as we explore the science of the Cannabis plant’s lifecycle.

So get ready to get dirty as we meet the Cannabis plant!

[INTRO]

These days Cannabis is big business. It wasn’t that long ago that Cannabis was almost an entirely underground industry. Very few people were willing to talk openly about it, and those that did often had to disguise their identities to do so. Today Cannabis is legal in some form or another in most states in the United States as well as Canada, Mexico and many other countries around the world.

More people are using Cannabis than ever before. Chances are, if you are listening to this podcast, there is a strong possibility you are one of these people. But what do you really know about how that little Cannabis bud in your child-resistant pop top container got there. Every Cannabis flower has a story to tell.

In this episode we are going to follow the lifecycle of a Cannabis plant from early evolution, to seed all the way to consumption and chart out many of the fascinating bits of science that are involved along the way.

And to guide our curious quest, we will focus on a few key questions:

One, what is Cannabis and how did it get here? Where does it fit in the big kingdom of plants?

Two, How does a harvested Cannabis plant turn into the perfectly manicured, aromatic, resinous buds that you might find at a dispensary?

Three, How does the chemistry of Cannabis change over time from the moment it is harvested to the moment it reaches the hands of a consumer?

And now, without further ado, let’s get started!

So, what is Cannabis?

Cannabis is a genus – which is one rank above species – and it belongs to the Cannabaceae family, which includes up to 9 or 10 other genera, like Humulus, which you are already familiar with if you are a beer drinker, because Humulus lupus, or hops, is commonly used to flavor beer.[1]

Recent research examining fossilized pollen from around the world has indicated that Cannabis and Humulus split from the same ancient ancestor approximately 30 million years ago.[2]

The Cannabis plant is thought to have really started is evolutionary journey somewhere around the Tibetan Plateau in Asia.[3] From there it moved around, following humans wherever we went, traveling from Western Asia up into Eastern Europe[4], back down into Asia, West into Africa and Western Europe. Then on to South America, Atlantic and Pacific Islands and finally North America.

Cannabis is thought to be one of the earliest ethnobotanical plants that humans have relied on for food, materials, and medicines. The seeds have been eaten for their nutritional value for thousands of years. There are reports of Cannabis being used for religious and recreational purposes going back at least five thousand years ago.[5] [6] Because of its value as a multi-functional botanical, humans throughout history have stewarded the Cannabis plant.

In each of the places where Cannabis has travelled, it has naturalized. It doesn’t actually take very long for Cannabis to adapt to a new environment. Reportedly this can happen in as few as 50 generations.[7] Given that Cannabis is generally an annual plant, that’s just 50 years or so. In the context of evolutionary history, this is a flash. These different varieties of Cannabis that have naturalized to unique geographical areas are called “landrace” varieties. Forgive the unfortunate terminology – it is what it is.

[ANGUS]

This is Angus of The Real Seed Company. He has traveled all over the world studying landrace Cannabis varieties.

[ANGUS]

So these are plants that are naturalized – but not necessarily wild. In fact, botanists and other researchers that have gone searching for truly wild Cannabis have had a hard time finding it. There is evidence of domestication in seemingly all Cannabis plants on the planet at this point. But this should not be surprising, right? We also don’t see wild versions of many of the vegetables we eat, because they have been domesticated for so long.

It’s also worth noting that the commercial Cannabis that you find in a dispensary, has little to do with these naturalized varieties. Commercial Cannabis is the result of intense hybridization and inbreeding resulting in the types of plants we traditionally think of when we think of Cannabis, but there is a lot more to Cannabis than what you see at a dispensary – but we will have more on that in another episode.

The Cannabis plant itself grows in varying forms depending on how it is cultivated, the plant’s genetics, and more.

The Cannabis leaf has become one of the most well recognized leaves on the planet, presenting a leaf structure that resembles a hand and is referred to as palmate. The leaf consists of 3 or more leaflets that somewhat resemble fingers. Each leaflet features serrated edges and a characteristic vein pattern where each vein splits toward the outer edge of the leaf to spread to both the outer tip and inner notch of each serration.

It is typically thought that Cannabis plants grow as either male or female plants. Female Cannabis plants produce the sticky resins containing the prized cannabinoids and terpenoids that so many people are after.

However this idea of a female Cannabis plant may not be quite right, as the Cannabis plant keeps many tricks up its sleeves, including the ability to produce male flowers and produce seeds on its own if it thinks it is in danger.

[REGGIE GAUDINO][8]

This is Dr. Reggie Gaudino. He is a molecular geneticist and research scientist that has been studying Cannabis for years. And his research has led him to believe that the notion of a true female Cannabis plant is a myth.

[REGGIE GAUDINO]

We’ve talked a bit about what Cannabis is and where it came from, but how is it grown? To answer this, we will follow the lifecycle of a Cannabis plant, starting with the seed.

Cannabis seeds contain several primary parts – the endosperm, which is a special kind of food to help feed the plant as it first starts growing, the cotyledons, which are the very first leaves that the plant will push out, and the seed coat, which protects the cotyledons and endosperm. When the seed absorbs a certain amount of water, life kicks into motion.

This moment when the seeds crack and start to push out roots is called “germination”. During this process, the plant is producing all sorts of hormones to quickly build roots, shoots and true leaves so that the plant can start using energy from the sun and have a decent chance at surviving.

But you have to be mindful that you know your seeds well. As plants are bred, they fall into a particular fiial generation. F1 plants tend to have stable, dominant traits. F2 plants tend to contain such a mix of genetics that many recessive traits emerge. With enough breeding through more filial generations, it is possible to eventually get to a stabilized inbred line of plants that are always consistent when grown from seed – however, this takes a lot of work and some debate whether it has ever happened in Cannabis yet.

Back in 2019 I spoke with a Cannabis farmer that had a nightmare scenario happen with Cannabis seeds that were supposed to be F1 hemp seeds.

[SAM MOORE][9]

Within a few weeks, depending on how much light the plant is getting, it will start to produce the earliest signs of sex organs – giving you a bit of insight into whether the plant is a male or female.

Cannabis produces two types of flowers – staminate flowers, which are the “male” flowers that produce pollen, and pistillate flowers, which are the “female” flowers that contain ovaries and produce resin.

If you don’t want to wait the 3 to 6 weeks it can take to sex your plants by eye, there are molecular tests available that can identify with varying degrees of accuracy whether your plants are male or female presenting.

Each bud is actually an inflorescence, which is the scientific word for a group of flowers. Each inflorescence of Cannabis contains lots of small irregular flowers, signified by a pair of what look like small hairs coming from each flower. The stigma, along with the fused style found at its base, is used to help pollen travel down to the ovary for pollination and fertilization.

Generally male plants are culled from the garden quickly to avoid pollination and seed production in the resin-producing female Cannabis plants.

Once these female presenting Cannabis plants begin producing flowers, they also start producing tons of cannabinoid and terpenoid rich sticky icky resin. And as long as the plants are not pollinated, they keep producing resin until the plant prepares to reach the end of its lifecycle. At this point the resin starts changing color, from clear, to cloudy to amber.

Each bud is actually an inflorescence, which is the scientific word for a group of flowers. Each inflorescence of Cannabis contains lots of small irregular flowers, signified by a pair of what look like small hairs coming from each flower. The stigma, along with the fused style found at its base, is used to help pollen travel down to the ovary for pollination and fertilization.

When the majority of trichomes are getting cloudy or amber, it’s time to harvest the flowers and allow them to dry – usually to a moisture content of around 8 to 12%. Personally, I recommend letting Cannabis dry more than you probably think it should, almost to the point of being cracker dry. This can be a bit scary at first – but trust me – that material is going to soak up any moisture from the air while curing, ultimately rehydrating the buds. You should expect to see the moisture content of the plant material go up a couple of degrees or more during curing.

You might be surprised how much water is in the air around us most of the time. Even in arid places like California or Southern Oregon, the air can often rest at humidity levels around 35 to 50%. In humid areas like the Southeastern United States, those humidity levels can be much higher.

When the plants are being harvested, the large leaves are clipped off. This helps ensure that air can move around the drying plants better and this helps prevent excess moisture from filling the drying space, ultimately reducing the potential of mold growth and expediting the drying process.

This drying process is a delicate process. If it happens too fast with too much heat, many terpenes and other volatile compounds besides water will be lost or degraded. As long as the drying process happens slowly at a low temperature, excess terpene loss should be kept to a minimum.

While the plant is drying, the chemistry starts changing. Besides the water leaving the plant material, aromatic compounds like monoterpenes are also leaving the plant, leaving behind heavier terpenes like sesquiterpenes.[10] One study found that while monoterpenes dominate freshly harvested Cannabis, which often have sharp and gassy aromas, the terpene profile of a plant rapidly changes as it dries to favor sesquiterpenes like beta-caryophyllene and humulene. This is because much of those monoterpenes literally jump off the plant during the drying process, ultimately raising the concentration of heavier terpenes, which tend to have spicier aromas overall.

The plant also off gasses other things while it is drying, like carbon dioxide, methanol, and ethylene.

[ALLISON JUSTICE][11]

This is Dr. Allison Justice, a plant scientist based out of South Carolina that has made it her mission to better understand how the Cannabis plant grows, and particularly – how it grows differently in different parts of the world.

[ALLISON JUSTICE]

Once dry, the plants are due for a good bucking. Bucking is the process of removing buds off of the large stems of the plant. This can be done by hand, as is often the case for craft Cannabis that is being treated more delicately, or there are also machines that have been designed to strip buds off of Cannabis plants as is the case in large scale Cannabis cultivation. Once the plant has been bucked, the buds can be trimmed to remove excess plant material before being stored for curing.

Once Cannabis plants have been chopped down, dried, and allowed to cure – they are then packaged – often in glass jars or vacuum sealed bags – to preserve the flowers’ aroma and moisture content. It’s at that point that the product makes its way from a grower, to a wholesaler, to a dispensary, and then to a customer’s hands.

But the Cannabis plant is not done changing yet.

As Cannabis is moved from container to container and exposed to oxygen and light, the chemistry starts changing once again. Terpenes oxidize, forming new aromas and tastes. Cannabinoids decarboxylate a bit and transform. Once THCA decarboxylates to THC, it then begins transforming into delta-8-THC and CBN.[12] Likewise, CBDA will decarboxylate to CBD, then transform to CBND and other derivatives.[13]

By the time a dried, cured inflorescence reaches a consumer – the chemistry can be substantially different than when it was harvested. This is one reason why “live resin” has become so popular. “Live Resin” is an extract produced from freshly harvested Cannabis plants that have not been allowed to dry and cure. Typically plants are cut down and immediately frozen and then stored until ready to be extracted. Live resin is typically associated with very loud aromas and flavors, often including more monoterpenes than would normally be found in the extracts of cured flower.

This has led to interesting debates between passionate connoisseurs and brands over the benefits of live resin vs. cured resin.

To each their own.

And just when we thought we were done, the Cannabis plant is still not done changing. The way you consume Cannabis affects its chemistry and what chemicals actually make it into your bloodstream.

When Cannabis is heated, all those cannabinoids, terpenoids and other chemical compounds begin to further transform into different chemicals, some that were never present in the plant to begin with.

[RILEY KIRK][14]

On the other hand, if you eat Cannabis, the chemistry will change in a different way. Those chemicals will travel through your digestive system to your liver where they will be metabolized and transformed before being allowed to enter your bloodstream.

But all of that chemistry of the Cannabis plant and its constituents is only one piece of the puzzle when trying to understand how Cannabis and Cannabis derived products affect the body. The other piece of the puzzle…is you. Your unique body and the unique ways in which it processes food, drugs and other compounds is a huge piece of the puzzle that often gets ignored.

Beyond your basic physiology that you bring to the table, there is also your psychology.

The setting in which you consume Cannabis will affect your experience. Your intention while consuming Cannabis will affect your experience. Consuming when you’re upset versus when you are happy will yield different experiences.

Cannabis affects everyone differently for a host of reasons – and no one really understands all the variables involved to predict how Cannabis will affect you. While there are all sorts of genetic tests, organoleptic training, and special recipes out there claiming to help you find what will work perfectly for you – at the end of the day, YOU are the only one that can know what works best for you. And you gain that understanding through experience and careful observation and reflection about your experiences.

If you want to learn more about how Cannabis affects the body, I recommend checking out our episodes on the endocannabinoid system and the endocannabinoidome!

Now, let’s review what we’ve learned.

First, Cannabis is a plant with a rich evolutionary history. It’s closest ancestor is the hops plant, Humulus lupus, which shared an ancient ancestor with Cannabis approximately 30 million years ago.

Cannabis has been used throughout history for many different uses, and is most commonly used as fiber, food, and medicine.

It is the pistillate flowers of the Cannabis plant that produce cannabinoid and terpene rich resins.

There are no true female Cannabis plants, as they all seem to have the ability to produce male flowers under stress.

Cannabis plants generally show their sex within 3 to 6 weeks of growth, depending on lighting conditions and the genetics of the plant itself. This process can sometimes be expedited by limiting light to only 12 hours a day

Male Cannabis plants are kept separate from resin-producing female plants to avoid pollination and seed production, or fertilization.

The chemistry of a Cannabis flower changes considerably from the moment it is harvested to the moment it is consumed.

Fresh Cannabis flower is rich in monoterpenes which quickly volatilize during the drying process, moreso that heavier terpenes like sesquiterpenes.

As Cannabis dries, the cannabinoids and terpenes in the resin begin to transform as they are exposed to air, light and heat.

When Cannabis is curing, it releases a variety of volatile organic compounds that influence the way cannabinoids and terpenes transform.

Then after the flower is packaged and sold to a consumer, another chemical transformation takes place when the flower is heated – producing hundreds of chemicals that were not present in the flower before it was heated.

Once consumed, each person’s body processes Cannabis a little differently, sometimes leading to very different experiences person-to-person.

There are no tests, techniques or recipes that will automatically connect you with the perfect Cannabis product or chemical profile for your specific need. You know yourself better than anyone, and only you have access to the physiological and psychological variables that also influence how you experience Cannabis, beyond the chemistry of the product itself.

That’s our show for today. I’m Jason Wilson[15] with Curious About Cannabis[16] asking you to stay curious and take it easy.

[1] John M. McPartland.Cannabis Systematics at the Levels of Family, Genus, and Species.Cannabis and Cannabinoid Research.Dec 2018.203-212.http://doi.org/10.1089/can.2018.0039

[2] McPartland, J.M., Hegman, W. & Long, T. Cannabis in Asia: its center of origin and early cultivation, based on a synthesis of subfossil pollen and archaeobotanical studies. Veget Hist Archaeobot 28, 691–702 (2019). https://doi.org/10.1007/s00334-019-00731-8

[3] McPartland, J.M., Hegman, W. & Long, T. Cannabis in Asia: its center of origin and early cultivation, based on a synthesis of subfossil pollen and archaeobotanical studies. Veget Hist Archaeobot 28, 691–702 (2019). https://doi.org/10.1007/s00334-019-00731-8

[4] McPartland, J.M., Guy, G.W. & Hegman, W. Cannabis is indigenous to Europe and cultivation began during the Copper or Bronze age: a probabilistic synthesis of fossil pollen studies. Veget Hist Archaeobot 27, 635–648 (2018). https://doi.org/10.1007/s00334-018-0678-7

[5] Clarke, R., & Merlin, M. (2016). Cannabis: evolution and ethnobotany. Univ of California Press.

[6] Russo, Ethan B. “The pharmacological history of Cannabis.” Handbook of Cannabis (2014).

[7] McPartland, J. Cannabis: the plant, its evolution, and its genetics—with an emphasis on Italy. Rend. Fis. Acc. Lincei 31, 939–948 (2020). https://doi.org/10.1007/s12210-020-00962-2

[8] The Curious About Cannabis Podcast behind-the-scenes #53 Reggie Gaudino PhD of Front Range Biosciences on Cannabis Genetics, Functional Cultivars, Landrace Biodiversity https://cacpodcast.com/bts-53-reggie-gaudino-phd-of-front-range-biosciences-on-cannabis-genetics-functional-cultivars-landrace-biodiversity/

[9] The Curious About Cannabis Podcast behind-the-scenes #21 Samuel Moore of Hillside Hemp Oregon on Sustainable Farming, Seed Sourcing, CBD https://cacpodcast.com/bts-21-samuel-moore-of-hillside-hemp-oregon-on-sustainable-farming-seed-sourcing-cbd/

[10] Ross, S. A., & ElSohly, M. A. (1996). The volatile oil composition of fresh and air-dried buds of Cannabis sativa. Journal of Natural Products, 59(1), 49-51. https://doi.org/10.1021/np960004a

[11] The Curious About Cannabis Podcast behind-the-scenes #77 The Science of the Cannabis Plant with Allison Justice PhD https://cacpodcast.com/the-science-of-the-cannabis-plant-with-allison-justice-phd-77/

[12] Russo, E. B. (2011). Taming THC: potential cannabis synergy and phytocannabinoid‐terpenoid entourage effects. British journal of pharmacology, 163(7), 1344-1364. https://doi.org/10.1111/j.1476-5381.2011.01238.x

[13] Van Ginneken, C. A. M., Vree, T. B., Breimer, D. D., Thijssen, H. W. H., & Van Rossum, J. M. (1973). Cannabinodiol, a new hashish consituent, identified by gaschromatography-mass spectrometry.

[14] The Curious About Cannabis Podcast behind-the-scenes #79 What’s In a Toke? Exploring the Chemistry of Cannabis Smoke and More with Dr. Riley Kirk https://cacpodcast.com/whats-in-a-toke-exploring-the-chemistry-of-cannabis-smoke-and-more-with-dr-riley-kirk-bts-79/

[15] www.jasonwilsonms.com

[16] www.cacpodcast.com | http://masterclasscannabis.com | http://learn.cacpodcast.com

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