The Germination Stage - The first of the marijuana plant stages is the same as it is for any plant matter – the seed. The cannabis plant actually uses sexual reproduction to generate seeds and disperse them. Each cannabis plant is either a male or female plant, and of course it’s the unseeded female plant that produces the quality marijuana bud that is so treasured among cannabis enthusiasts.
The meeting of male and females plants leads to the production of seeds, and that’s why female cannabis plants that are earmarked for marijuana production are kept isolated from even the slightest moment of interaction with a male plant.
Cannabis seeds remain dormant until exposed to water and light, and once they are exposed to both elements the germination stage begins. Hormones in the seed are activated and growth begins. A root will grow down and split open the shell of the seed, and shortly thereafter the plant’s stalk shoots out the top of the seed before sprouting two initial cotyledon leaves.
These leaves are meristems, and once they’ve emerged from the seed then extensive cell division begins to occur within them. The reproduction of leaves or stems during this cell division part of the marijuana plant stages is when you have the ability to take clones, but once a meristem cell begins producing roots the clone window closes as the fledgling plant will no longer reproduce leaves or stems.
The Sprout Stage As moisture enters the seed through micropyles – tiny porous openings in the seed – the seed begins to sprout. Once it is ready to exist on its own without the shell, it will burst completely free of it and no longer able to survive in a dry environment. From this point forward in the marijuana life cycle it will need a regular and consistent supply of heat, water, and air in the same way any plant will. The sprout stage is the shortest of all the marijuana plant stages.
The Seedling Stage Next up in the marijuana plant stages is the seedling stage, and this is when the plant is at its most vulnerable. At this stage the root systems at the base of the plant really start developing extensively, and leaves begin to spread out and grow at the top of the plant. With a healthy plant this stage should last 3 to 7 days, after which a full seedling will have established itself. This stage being complete is marked by the plant having ‘true leaves’.
True leaves are ones that have the same classic 7-point ‘fan’ leaf structure as mature leaves, and once they’re seen on the plant then this one of the marijuana plant stages is complete. However, your plant can remain in the seedling stage for anywhere between 3 to 6 weeks, and often this is dependent on the strain.
Regarding the vulnerability mentioned above, it is essential that heat and humidity levels are maintained within a certain spectrum during the seedling stage. You can learn more about this when consulting a reputable source on growing marijuana.
The Vegetative Stage Of all the marijuana plant growing stages, it’s fair to say that the vegetative state is most encouraging and promising for the people growing the plant. This is where the plant really develops and starts to ‘bush out’ with foliage as it becomes more capable of absorbing and processing greater quantities of carbon dioxide and other nutrients.
During this stage of the marijuana life cycle the plant’s roots continue to expand and the plant begins to grow taller as a result. Healthy cannabis plants can grow up to 2 inches in a single day during the vegetative stage. Light exposure is of paramount importance during this one of the marijuana plant stages.
The Pre-Flowering Stage The best time to identify the sex of your marijuana plants is during their flowering time. Male and female characteristics will start to show up during this phase. Therefore, it is very important that you learn what to do during the pre-flowering and full-flowering periods of weed growing.
The pre-flowering time which will usually start during the 4th week of the vegetative phase. It is hard to detect if the plants are already pre-flowering unless you will use a magnifying glass. It takes expertise for you to identify the sex of cannabis during the pre-flowering period of marijuana growing. During the pre-flowering, small pear-shaped nodes appearing on the 4th node of the stem can be seen if the plant is female.
At this point, you are now starting to see some signs that they are in the pre-flowering phase. Once most of the strains reach a particular level of maturity or size, they show signs that they are now ready to enter another level. If you use regular seeds, you can take advantage of this phase to identify the male plants, removing them from the bunch. Keep in mind that even a small release of pollen at this point may lead to having seeds later on. This is fine if you are growing plants for breeding purposes, but if you are growing medical marijuana, removing the males may be best at this point.
The Flowering Stage This is the end stage of the marijuana life cycle, as after this stage the plant becomes ready for harvesting. The female cannabis plants that have been grown from seed and then kept separate from male plants will reach maturity and begin to produce their precious buds. Indeed, of all the marijuana plant stages the flowering stage is the one that marijuana enthusiasts will regard as the most promising!
The flowering stage is dependent on the plant receiving a reduced amount of light, which will occur naturally if growing outdoors as the fall season approaches. But, if you’re growing indoors with artificial lighting, you should dial back the hours of the day the plant receives light. When a cannabis plant reaches its flowering stage it produces plenty of sticky resin on the outside of the leaves, and the concentrations of these THC-containing resins are found in large quantities in the buds just below the leaves.
The flowering stages for most strains last between 6 to 10 weeks, and in order to harvest the best buds it’s important to let this stage be completed in its entirety. You can tell when a flowering stage is complete when 70 to 90% of the pistils (aka ‘hairs’ on the buds) turn brown and large leaves shift from deep green to more of a green / yellow colour. This will indicate the last of the marijuana plant stages has passed, and you’re now ready to harvest.
The modification of a plant's growth habit is called training. Indoor cultivators employ many training techniques to encourage shorter plants and denser canopy growth. For example, unless the crop is too large to be extensively pruned, cultivators remove adventitious growth shoots, often called suckers that are near the bottom of the plant and/or receive little light and will produce poor quality buds. Some cultivators employ plant-training techniques to increase yields indoors:
Topping is the removal of the top of the apical meristem (dominant central stem), called the apex or terminal bud, to transfer apical dominance (the tendency for the apex to grow more rapidly than the rest of the plant) to the shoots emanating from the two nodes immediately beneath the pruning cut. This process can be repeated on one or both of the two new meristems, when they become apically dominant, with the same results. This process can actually be repeated nigh infinitely, but over-diffusion of apical dominance produces smaller, lower quality buds, so it is usually done no more than a few times. Topping also causes more rapid growth of all of the branches below the cut while the plant heals.
Pinching (also called "FIMing") is similar to topping in that it causes lower branches to grow more rapidly, but the apical meristem maintain apical dominance, which is especially useful if the plant has already been topped. Pinching is performed by firmly pinching the apical meristem(s) so as to substantially damage vascular and structural cells but without totally breaking the stem. This causes lower limbs to grow more rapidly while the pinched tissue heals, after which time the stem resumes apical dominance.
LST stands for Low Stress Training and is another form of super cropping, many times referred to as LST super-cropping. This technique involves bending and tying the plants branches to manipulate the plant into a more preferred growth shape. This method of training works very well for indoor growers who need to illuminate their plants using overhead lights. Since light intensity greatly diminishes with increased distance (Inverse-square law), LST'ing can be used to keep all growth tips (meristems) at the same distance from the light and can achieve optimal light exposure. LST can be used in conjunction with topping, since topping increases axial growth (side shoots). Topping is often done a few weeks before beginning LST'ing. The training works by changing the distribution of hormones—more specifically auxins—in the plant. LST'ing resembles the training of grape vines into their support lattices. Outdoor gardeners also employ training techniques to keep their plants from becoming too vertical.
In contrast to the "Screen of Green" method, Sea of Green (or SOG) growing depends on the high density of plants (as high as 60 per square meter or 6 per square foot) to create uniformity in the crop. In this technique, which is often grown in hydroponic media, only the colas of the plants are harvested. Containers are used to enforce the geometric distribution of flowers and plant material, as well as their exposure to lighting and atmosphere. Sea of green is popular with commercial cultivators, as it minimizes the amount of time a plant spends in vegetative stage, and allows very efficient light distribution, keeping the plants much closer to the lights than when grown to full size.
SCROG, short for SCReen Of Green, is an advanced training technique for cultivating Cannabis, mainly indoors. Closely resembles SOG (or Sea Of Green) with the difference being that SCROG uses extensive training to produce the same field of bud effect with only one plant. Medical growers may find this a helpful technique to maximize harvest if they are only allowed a certain number of plants. A screen such as chicken wire is hung over plants so that the tips of branches are kept at the same level. This allows even light distribution to all of the nodes/bud sites. Once the flowering stage begins, the flower tips reach through the wire and are at relatively equal distances from the light source.
Timing: Timing is vital to the success of a SCROG grow. If the net is not full at harvest, valuable space has been wasted. If the net is too full then the buds will be too crowded to develop properly. Knowing how a plant grows can help to visualize when to flower for maximum effect.