The Cannabis Life Cycle

Cannabis is what is known as an annual plant. This means that cannabis goes through its entire life cycle within a year. Most strains of cannabis complete their life cycle, from seed to death, in 4-10 months.  Cannabis is one of the few annuals that tend to have separate male and female plants. However, it is not unheard of for a cannabis plant to turn into a hermaphrodite* (a plant with both male and female organs) in times of stress. This is especially the case in the wild, where cannabis strains do not have human intervention or care.

The Cannabis Life Cycle


The process by which a plant grows from a seed. The most common example of germination is the sprouting of a seedling from a seed.  This is the very beginning. All that is required to start germination is water, air and heat; the seed will use these to produce food and start its rapid growth. As the seed germinates the first shoot will grow and break out of the shell, this is the tap root. There are many different techniques to germinate seeds.  Some just put seeds directly in soil, some in a glass with water.  We follow the Serious Seeds method and put the seeds in a damp paper towel, then a ziplock bag that gets hung on the fridge (the roots will all grow in the same direction this way).  Once there is a tap root of about half an inch, we put the seed and root in soil, root pointing down, leaving the seed husk visible.  After this the plant will begin to grow, forcing its way upwards. It produces its first two leaves (known as the cotyledons), which should force the seed shell off the plant and open the way for them to catch light. The primary task of a newly germinated seed is to obtain as much light energy for food as possible through its new leaves (the first set are called cotyledons).


Once the plant has its cotyledons it will focus on developing its next set of leaves.  The cotyledons are not true leaves but contain food for the young plant for the first few days.  The next pair of leaves that appear are true leaves and are single (and look like little airplane propellers). These will look more stereotypical leaves of a cannabis plant; they will be larger with a serrated edge and the elongated “finger” look that is typically associated with the plant. The focus of the seedling stage is to produce those initial few leaves and build a strong, expansive network of roots in order to facilitate future plant growth. This stage usually ends when the cannabis plant has fully developed its first few sets of leaves. It will have a stem thickness of around 4-6mm and be 3-4 nodes* high. 

Vegetative Period

This is the main growing phase of the plant where it will turn from a small seedling into a large, beautiful cannabis plant. It is in this phase that the plant will require all the light and nutrients it can use – just be careful not to overfeed it nutrients, (a common rookie error). Overfeeding and overwatering can be prevented by using small pots and transplanting every couple weeks (when the plant starts to hang over the pot).  You can use fabric pots (like these) which help with drainage and airpruning the roots. Once you get more advanced and understand how much water the plant needs, you do fewer transplants (and I would argue that the transplant can be stressful on its own).  We grow in our final destination pot immediately after the seedling stage, and are very careful not to overwater--that takes time to understand and gauge properly and is not recommended for most.

Indoors, the grower would use 18-24 hours of light to mimic summer daylight.  Your vegetation light is based on preference:  increased dark hours will lower electricity bills, but more light hours allow for taller and bulkier plants.  We usually go with 20 hours during veg.  If the plant has what it requires, it will start by continuing to grow upwards towards the light, producing new leaves while thickening its branches and stems.  

When the plant begins to reach a certain level of maturity it will start to focus its efforts bulking outwards instead of upwards, creating more branches and nodes. At this point you can start looking for "pre-flowers." These are tiny versions of adult sex parts, and when you see them you can tell what gender the plant is going to be. They usually show up in the upper parts of the plant, closer to the light.  Finally a calyx start to form around the nodes of the plant, and you are in the final part of the vegetative period.  This is an indication that the plant is ready to flower.  Alternatively, if you have male plant, it will start to form tiny pods that will eventually produce pollen to pollinate* another plant.

Flowering Period

The flowering period starts towards the end of summer, when the plant gets less light as the days get shorter (indoors, the light cycle is reduced to 12 hours light, 12 hours dark). This is an indication to the plant that its life cycle is nearly up, and it needs to think about reproduction. It is around this time that the males will start to produce pollen and the females produce flowers (buds). Should the females' flowers come into contact with the male pollen then they will begin to produce seeds within their buds. Once seeds are made the buds will open in order to allow for the seeds to disperse by natural means and start the entire life cycle all over again.  Cannabis cultivators tend to worry about their females getting pollinated because seedy pot is not good for smoking. The best way to overcome this is to move males to a separate place as soon as they are identifiable and stop any risk of contamination.  It is always best to produce seeds in a separate area, away from the main crop.


The harvest is not a natural part of the cannabis life cycle per se, but for the grower this is the most crucial and anticipated part of the grow. It is very important to get the timing just right here. Growers must be very careful not to cut down plants that are not yet at the pinnacle of resin production, but they must also be wary of cutting plants too late—at a time when THC production has curtailed, and trichome resin glands begin to degrade (along with other issues, like mould setting in).  There are various methods by which even the most amateur grower can tell when buds are truly ripe for the picking. The simplest and quickest way to know is by examining the pistils, or long hairs, that cover the plant’s buds. At the onset of flowering, these pistils are white and stringy. But as the flowering period comes to an end, they begin to turn color, first from white to orange and then again to a dark red, pink or brown.

These color changes signify the maturation of the buds; however, the color and time frame may vary significantly across different varieties of cannabis. The best method for determining ripeness is through trichome examination. Trichomes are the actual resin glands that contain THC and other psychoactive cannabinoids, and they are very delicate and easily ruptured. These trichomes are visible on the outside of buds and small leaves and look like little white sugar crystals to the naked eye. However, with the power of a magnifying glass or simple microscope, you can see that trichomes are comprised of a stalk and resin head (that look like a penis) and are clear or white in color. 

As with pistils, trichomes also begin to change color as the buds mature. But in this scenario, a grower wants to harvest buds before they get too dark in color. Even a subtle amber hue in these glands could mean that cannabinoids have begun breaking down and decomposing, which means less potent pot. Advanced growers use a 45x-100x microscope and look for a creamy or milky white color in the trichomes that tells them it’s time to harvest.  We usually aim for 75%-80% milky, 10%-15% amber, 5%-10% clear. 


Once you have your ideal trichome level (whatever it may be), using trimming scissors (like these), cut down the plants, and start trimming the leaves.  As you are cutting down the plant, inspect your bud carefully and ensure that you are not trimming plants that have bud rot (a fluffy looking mould that only appears in the last week or so of flowering that you may have missed).  Your goal is to trim all the leaves off.  We hold the bud upside down and clip the veins of any leaves we see, trying to get them out whole.  Any excess leaves will look weird and shriveled when the bud starts to dry so try to focus on getting the veined leaves fully and then just trim the edges of the rest.  You could leave more leaf on there, especially if it is coated in trichomes, but the final end product could look gnarly.  Those extra leaves are better saved for hash production.  You can also avoid trimming the buds that are on the bottom of the plant--they dry to almost nothing and aren't worth the time you will put into them.  Those under buds are also a good choice for hash production.  Make sure you trim most of the stem off and be as close to the bud as possible (leaving a long stem is a pain in the jarring and curing process).

Drying + Curing

As soon as you have trimmed all your buds, put them onto a mesh dry rack (like these)  and let them sit there for at least a week.  The buds should be a little bit crispy and the stems should be a little bendy (and thinner stems should snap easily).  The buds will shrink a significant amount (and this is when you will see how good or bad your trim job was).  After the week on the dry rack put your buds in a glass jar and seal.  The main point of the curing process is to bring out the scent and flavour, and takes about a month (sometimes longer).  It's pretty simple--keep in a dark place and open the lid everyday for 10 or 15 minutes.  It will take 1 month and up to 6 weeks to fully cure your cannabis.  You can smoke before that time, but you won't be able to fully appreciate the flavour before then.


Hermaphrodite:  A plant with both male and female organs.  You may hear customers shorten this term to “hermie”.  Hermaphrodism is caused by outside stressers (like a disruption in the light cycle—letting light into room when the plants are supposed to be sleeping in the dark for example).

Nodes:  The stem is normally divided into nodes and internodes: The nodes hold one or more leaves, as well as buds which can grow into branches.  Internodes are the interval spaces between the nodes on the stem. 

Pollination (Pollinate):  Occurs when pollen from the male marijuana plant reaches the female stigmas and finds its way to the egg cell of the female plant that is inside the pistil. After the process of pollination, the seed is produced.  Hand pollination is when a breeder takes the pollen from the male plant with a brush and dusts it on the female plant.  Outdoors pollination would occur naturally with wind blowing pollen from one side of a grow space to another.

Leave a comment

All comments are moderated before being published