The Cannabis Plant: Anatomy, Hemp, Indica, Sativa, and Cultivation Methods

Before becoming a dried flower, resin, or oil, cannabis is first and foremost a plant. Understanding its structure, its different varieties, and the way it is grown helps to better grasp the differences between weed, hash, industrial hemp, or recreational cannabis.

Hemp, marijuana, cannabis: what exactly are we talking about?

From a botanical perspective, hemp and marijuana belong to the same species: Cannabis sativa L., from the Cannabaceae family (the same family as hops). The difference therefore does not lie in the species, but in the use and especially in the THC content.

Hemp generally refers to cannabis varieties containing a very low amount of THC (tetrahydrocannabinol), below a legal threshold set by each country. These plants are used for fiber, seeds, food supplements, or CBD production.

Conversely, varieties rich in THC, intended for medical or adult-use purposes, are commonly called marijuana or “adult-use cannabis.” They are selected for their cannabinoid and terpene profiles, and therefore for their effects and aromas.

Anatomy of the cannabis plant

Each part of the plant plays a specific role, whether for cultivation, extraction, or consumption.

The flower (or bud)

On female plants, the flowers appear as small compact structures, often called buds. They contain the majority of the cannabinoids and terpenes.

Colas

The cola is the large cluster of flowers located at the top or on the main branches. It is usually the most voluminous and sought-after part of the plant.

Bracts and pistils

Bracts are small leaves that surround the reproductive organ of the flower. They protect the seeds when pollination occurs. Inside sits the pistil, topped with thin colored filaments called stigmas, which capture pollen from male plants.

Trichomes

Trichomes are tiny resin glands that cover the flowers and, to a lesser extent, certain leaves. They function like microscopic factories: they produce cannabinoids (THC, CBD, CBG, etc.), terpenes and flavonoids that give cannabis its effects, flavor, and aroma.

The more trichomes a flower has, the shinier and stickier it appears. This resin is the base material for making hash, concentrates, and many extracts.

Fan leaves and sugar leaves

The large characteristic leaves of the plant, often depicted as “cannabis leaves,” are called fan leaves. They play an essential role in photosynthesis.

Near the flowers, smaller, narrower leaves covered in trichomes can be found: these are the sugar leaves. They are often removed during trimming, then used to produce hash or concentrates.

Stem, nodes and roots

The main stem supports the plant and transports water and nutrients from the roots to the leaves and flowers. The nodes are the points where branches and leaves separate from the stem. These nodes are also where growers can identify the plant’s sex at the beginning of the flowering stage.

Trichomes: where everything happens

Put simply, most of the “magic” of cannabis happens inside the trichomes. This is where the plant synthesises:

• Cannabinoids (THC, CBD, CBG, CBC, etc.);
• Terpenes, responsible for citrus, pine, diesel, spicy and many other aromas;
• Flavonoids, which also contribute to colour and aroma.

The interaction of all these compounds is often called the entourage effect: the whole plant, with its complete mix of molecules, seems to provide effects that differ from those of an isolated cannabinoid taken alone.

Indica, sativa, hybrids: how to navigate?

Historically, plants were distinguished mainly by their appearance during cultivation:

• Indica-dominant plants: shorter, stockier, broad dark leaves, fast flowering.
• Sativa-dominant plants: taller, more slender, thin light leaves, longer flowering.

In shop and dispensary menus, these terms later became associated with effects: indica more relaxing, sativa more uplifting. In reality, modern cultivars are almost always hybrids, and effects depend above all on the full cannabinoid and terpene profile, as well as each consumer’s sensitivity.

To choose a product, it is better to check:

• THC, CBD and other cannabinoid levels;
• the dominant terpene types;
• your own experience and tolerance.

How is cannabis grown?

Cannabis is an annual plant that loves light and warmth. Depending on goals and climate, it can be grown in several ways.

Outdoor cultivation

In outdoor setups, plants benefit directly from sunlight and a large root zone. Costs are lower, but the crop is exposed to weather, pests and soil quality. In favourable regions, plants grow large with high yields.

Greenhouse cultivation

A greenhouse combines natural light with partial protection from bad weather. Additional artificial lighting or blackout systems can be used to fine-tune photoperiod and flowering.

Indoor cultivation

Indoor growing offers the highest level of control: light, temperature, humidity, ventilation, substrate and nutrients can all be adjusted precisely. The downside is higher installation and electricity costs.

Seeds or clones: two ways to start a grow

Seeds

Growing from seeds produces robust plants with strong vigour and a solid root system. Feminised seeds are preferred when flower production is the goal, as they produce almost exclusively female plants.

Clones

A clone is a cutting taken from a mother plant selected for its qualities. It is a genetic copy of the original plant. The main advantage: predictable behaviour (structure, aroma, cannabinoid profile) when grown under similar conditions.

Industrial hemp: a multi-purpose plant

Industrial hemp is grown for many purposes other than cannabinoid-rich flowers. Depending on the variety and processing method, it can be used to produce:

• Fibres for textiles, ropes, insulation or construction materials;
• Seeds and hemp oil for food;
• Supplements rich in proteins and essential fatty acids;
• Biomass for industrial or energy use.

Depending on local laws, these crops must maintain a very low THC content, while still being able to produce significant CBD levels.

In conclusion

The cannabis plant is far more than a finished product sold as flowers or resin. It is a complex organism in which every part — from trichomes to roots — has a specific role and potential. Behind the single word cannabis lies an entire family of plants: industrial hemp, THC-rich cannabis, CBD varieties, indica, sativa and hybrids.

Cannabis cultivation: from seed to harvest

Growing cannabis is not just putting a seed in soil and waiting. From choosing the growing medium to germination, growth phases and harvest, every step matters. Here is a clear and accessible overview of the basics of cannabis cultivation, whether indoors, outdoors or in a greenhouse.

Choosing your growing medium: soil, hydroponics, aeroponics

The growing medium is the “home” of the roots. It must provide water, oxygen and nutrients to the plant. Three main approaches exist: soil growing, hydroponics and — less common among home growers — aeroponics.

Soil: the simplest base

Soil remains the most tolerant and popular choice. Good cannabis soil is light, well-draining yet able to retain some moisture. It often already contains organic nutrients (compost, humus, guano etc.), giving beginners a margin for watering errors.

To start, quality ready-to-use soil and regular watering are more than enough to achieve healthy plants.

Hydroponics: precision and speed

In hydroponics, the roots are no longer in soil but in a neutral substrate (coco, clay pebbles, rockwool, etc.) irrigated with a nutrient solution. The roots have direct access to water and nutrients, which allows for faster growth and often higher yields.

The trade-off is that hydroponics requires more discipline: you need to monitor pH, water temperature, and nutrient concentration. A mistake can affect the plant very quickly.

Aeroponics: high yield, high demands

Aeroponics is an advanced form of hydroponics. The roots hang freely in the air and are regularly misted with a fine nutrient spray. The growth potential is very high, but everything depends on the reliability of the system and tight environmental control. A pump failure or poorly managed temperatures can quickly become critical.

Starting a grow: seeds and clones

Seed germination

Germination is the moment when the seed “wakes up” and reveals its small white root, the taproot. Several methods are possible:

• Directly in soil: the seed is placed in a small pot with slightly moist soil, at shallow depth (about 0.5 to 1 cm).
• Paper towel method: the seed is placed between two moist sheets of paper towel, then transplanted into a pot as soon as the root appears.
• Germination plugs or cubes: designed to keep moisture stable, very convenient for beginners.

A fresh, good-quality seed generally takes between 24 hours and a few days to germinate, depending on the variety and conditions.

Rooting clones

A clone is a cutting taken from a mother plant, intended to develop its own roots. It allows you to reproduce a genetics you already like (flavour, effect, vigour, etc.) identically.

Clones are usually placed in a light medium (rockwool cubes, coco plugs, small rooting plugs) and kept in a very humid environment with gentle lighting. Once a solid root system has developed, they can be transplanted into their final grow pot.

The main life stages of a cannabis plant

Vegetative phase

The vegetative phase is the period during which the plant focuses on growing stems, roots and large fan leaves. Indoors, a light cycle of 18 hours of light / 6 hours of darkness is commonly used.

The longer the vegetative phase, the more time the plant has to develop and create future flower sites. This is also the ideal time to apply different training techniques.

Flowering phase

Flowering begins when the plant receives shorter days. Indoors, growers typically switch to a 12 hours light / 12 hours darkness schedule. Outdoors, this change happens naturally as summer ends.

During this phase, the plant directs its energy into producing colas covered in trichomes. Nutrient regimes change as well: nitrogen is generally reduced, while phosphorus and potassium — more useful for flower formation — are increased.

When to harvest?

Growers often monitor the trichomes with a loupe or microscope: when they turn cloudy, then slightly amber, it usually indicates the plant has reached its peak. The colour of the pistils (shifting from white to orange/brown) is another complementary indicator.

Training techniques: getting the best from each plant

Training techniques help optimise light distribution, increase the number of flower sites and adapt plant shape to the available space.

• SOG (Sea of Green): many small plants, short veg time, one main cola per plant — ideal for small spaces.
• SCROG (Screen of Green): the plant is grown through a horizontal net to create an even canopy, perfect for maximising a few plants.
• LST (Low Stress Training): gently bending and tying down branches to open the plant without breaking it.
• Topping & FIM: cutting or pinching the main apex so the plant forms several main tops instead of just one.
• Lollipopping: removing the small lower branches and leaves so the plant’s energy is focused on the top, where the light is strongest.

Harvest, drying, trimming and curing

Cutting

When the plant is ready, either the whole plant is cut or the branches are removed one by one. From this point on, trichomes must be protected: avoid rough handling, shocks, excessive heat and direct light.

Drying

The flowers are usually hung upside down in a dark, ventilated, temperature-controlled space. The goal is slow drying: when the small stems snap rather than bend, it is time to move on to the next step.

Trimming

Trimming consists of removing excess leaves around the flowers. Some growers prefer to trim right after cutting (wet trimming), others after drying (dry trimming). The resinous “sugar” leaves can be kept to make hash or concentrates.

Curing: the often overlooked stage

Curing is the slow maturation of flowers in airtight jars. Buds are placed in glass jars, which are opened regularly in the first weeks to let excess moisture escape. This process refines aromas, smooths the smoke and helps stabilise cannabinoids and terpenes.

Good curing usually takes several weeks, and sometimes a few months for the best result.

Indoor, outdoor and greenhouse: which environment to choose?

Indoor: maximum control

With indoor setups, almost everything can be controlled: light (HPS, MH, LED), temperature, humidity, air circulation, CO₂… It’s ideal for achieving consistent harvests all year round, but initial costs (lighting, ventilation, climate control) are higher.

Outdoor: the power of the sun

In outdoor grows, plants benefit from the full spectrum of sunlight and a large volume of soil. It’s an economical and ecological option, but dependent on climate, soil quality and how discreet the grow can be.

Greenhouse: the best of both worlds

A greenhouse combines natural light with partial protection from the elements. With light-deprivation systems to manage daylight, it’s even possible to achieve multiple harvests per year.

Why lab tests matter

A good product cannot be judged by appearance or smell alone. Lab tests make it possible to verify:

• Cannabinoid content (THC, CBD, etc.);
• the terpene profile (aromas, type of effects);
• the absence of unwanted residues (pesticides, heavy metals, moulds, solvents).

This is crucial for medical users, but it is also a strong sign of transparency and quality for everyone.

In summary

From seed to perfectly cured flower, cannabis cultivation is a balance of technique, observation and patience. Choice of growing medium, management of growth phases, training techniques, harvest and curing — each step shapes the final result. By taking the time to understand these basics, you also gain a clearer picture of what stands behind every quality bud.