Life cycle of Cannabis Cannabis passes through a series of stages in its life. The most important of these are the germination, seedling, growth and flowering stages. Each stage brings its own challenges. Novice growers need to be aware of these, to be sure of giving their plants the attention and care that they deserve.
Plants are living beings. They are at the base of the evolutionary tree, they heal our bodies and souls, they delight our senses. I think all our readers know by now which is our favourite plant: Cannabis sativa L. – a fantastic crop and medicinal plant, and one of the oldest plant genera in the world.
No matter why cannabis is being cultivated, to see with your own eyes how a small seed grows into a bulky plant, which then starts flowering, is a moving experience every time.
Cannabis is an annual plant, so its entire lifecycle takes place within a single year, with most varieties reaching the end of their life after between four and ten months. In general terms, the following four stages of life can be distinguished:
A quick glance is usually enough to determine the current stage. Over time, it is not just the appearance of the plant that changes, its needs also change. Different stages require different quantities of light, water and nutrients. Furthermore, if you want to determine the sex of the plant or prune it, it is useful to know which stage the plant has currently reached.
1 – Germination stage (1 to 2 weeks)
All forms of life start from a seed of some kind. High-quality seed is the single most important factor for successful cultivation. Cannabis seeds should be hard, dry and brownish in colour. There are a number of different ways of getting the seeds to germinate. The easiest is the paper towel method.
In the germination process, the germ in the seed breaks through its shell and forms a root, which is known as the taproot. Germination takes anything from 24 hours to 7 days. Generally cannabis varieties with a high proportion of Indica germinate faster than pure Sativas.
The germinated seed can now be placed carefully into the growing medium. The plant will start to grow and force its way upwards.
While the first two cotyledons (seed leaves) are being formed, the plant shrugs off the protective seed husk. That signifies the end of the germination stage.
2 – Seedling stage (2 to 4 weeks)
Particular care is necessary at this stage in the lifecycle. Seedlings are susceptible to illnesses and mould. Many novices get carried away with watering and give the seedlings too much fertiliser. Even if you plan to grow outdoors, it may be useful to give the plants a healthy start indoors, assuming that a location is available with adequate light (e.g. a windowsill). The plants need as much light as possible at this stage.
How long the seedling stage lasts depends on the variety and on the environmental conditions. The main focus of the plant is on developing a root system. This forms the foundation for its later growth.
Meanwhile the plant will grow its first “real” leaves with the characteristic marijuana shape.
The leaflets are long and jagged. Initially a leaf has just one leaflet, although a mature cannabis plant will have five to seven leaflets per leaf.
Once the plant produces the full count of leaflets for each new leaf, the seedling stage is over.
3 – Growth stage or vegetation stage (2 to 8 weeks)
Now the plant starts its main growing phase. Provided it receives enough light, it can grow up to two inches (5 cm) in a single day. It is obvious that the plant needs to be repotted if it is still growing in a small pot.
Leafy plants like a healthy soil that is rich in nutrients. The production of chlorophyll and proteins depends on a supply of nitrogen. It is worth investing in the right kinds of fertiliser or even producing them yourself.
As it grows, the plant also needs more water. Young plants are best watered close to their stem, but later on water should be distributed more widely so that the tips of the roots can absorb water more efficiently.
Have you ever heard of topping, super-cropping or lollipopping? Using these techniques you can train cannabis or manipulate the shape of the plant. Growers use them to develop stronger plants with more buds. Opinions vary, however, on whether these techniques actually deliver results. They are only necessary for special cultivation methods such as the Screen of Green (SCROG).
How long the growth phase lasts is not a simple question to answer. Auto-flowering cannabis varieties move automatically on to the flowering stage within 2 or 3 weeks. Regular or feminised varieties only start flowering once the days become shorter (outdoor cultivation) or the grower reduces the lighting period to 12 hours (indoor cultivation).
4 – Flowering stage (4 to 12 weeks)
For most people, the flowering stage is the most exciting stage in the lifecycle of a cannabis plant. Once the days become shorter and the plant receives less light, it starts to take care of reproduction.
Only now can the sex be determined with any certainty. While male plants produce pollen, the female plants pour their energy into producing flowers or buds. Most growers want to prevent their female plants from getting pollinated, because then they start to produce seeds. That is why male plants should be removed from the growing area.
Some growers use special fertilisers during this stage to stimulate bud formation. During the flowering season, cannabis plants need plenty of water. They may need to be staked to help support the weight of the buds. In order to avoid disrupting hormone development, the plants should not be pruned after the second week of the flowering stage.
The length of the flowering stage again depends on the varieties being grown. Auto-flowering cannabis can be ready to harvest within as little as one month, while Indicas need about 6 to 8 weeks. For some Sativa varieties it can take longer than 3 months for the right harvest moment to arrive.