Cannabis is an annual plant. When cultivated in the wild, the seeds are sown in spring and develop into stately and sometimes very large plants over the course of the summer, which then flower in autumn.
Cannabis plants are bisexual by nature, which means that cannabis plants can be male or female. For reproduction, i.e. for the production of seeds, both sexes are normally needed, i.e. a male and a female plant.
When it comes to growing high quality, potent and medicinally valuable weed, the male plants are completely in the way and therefore mostly undesirable. They take away a large part of the potency of the female plants when they start pollinating them. The female plants then consequently start developing seeds and produce less resin and THC. For this reason, when growing weed, all male plants are sorted out and destroyed early, before they can do any "damage" and get too close to the ladies.
Feminised seeds were developed by humans and are created through special methods and breeding procedures. Feminised seeds produce 99% female plants, eliminating the need to sort out male plants.
The life of a cannabis plant
1. germination:
Most seeds will germinate within 3-7 days if the environmental conditions are suitable and the seeds have been stored properly. During germination, the embryo inside the seed is activated by moisture, heat and oxygen. It expands and is nourished by a nutrient reserve inside the seed. After a relatively short time, the outer seed coat bursts open and a white plant root, which grows downwards, appears. The two cotyledons show themselves and immediately look for light.
2. seedling:
The taproot grows downwards due to gravity and branches out in a similar way to the plant above ground. These small branches of the roots are also called secondary or lateral roots. Seedlings receive 16-24 hours of light. Usually, in this phase (growth phase), one chooses an exposure time of 18 hours.
3. the growing phase:
Usually lasts 4-6 weeks. With many cannabis strains, the growing phase lasts and continues as long as the plants are lit every 24 hours with 18 hours of light. During this time, the plants keep growing, branching and getting bigger. When grown outdoors, the cannabis plants are in the growing phase until the days naturally become shorter again and the sunlight has a higher reddish component. This is the case in late summer or autumn. The marijuana plants then get the signal to start flowering and make hormonal changes.
Similar to how the root system continues to develop and reveal itself throughout the growing phase, the branches and ramifications develop above ground. The root system starts to fill the planting medium and digs further and further into the planting medium to get more water and nutrients. Countless secondary roots with very fine hairy roots form, which are there to supply the plant with sufficient nutrients and water. If the planting medium dries out completely, the fine hair roots are severely damaged and die. They can also die and be torn off if the plant is pulled out of the plant pot too carelessly and roughly. A strong root growth and system of the plants is the most important basis for an optimal grow.
Wind (outdoor) or fans (indoor, greenhouse) ensure strong stems and trunks. As soon as green colour is visible, the formation of carbohydrates starts in the plants and energy is produced from sunlight and nutrients from the soil. This process is called photosynthesis. Chlorophyll gives plants their green colour. It is contained in the cellular structures of plants.
4. prebloom
Cannabis plants grown from seeds typically show an early stage of flowering, the so-called pre-flowering. The majority of cannabis strains form pre-blooms after the 4th-5th week of the growing phase, showing in advance which sex they are. Male plants can be safely removed at this point. If you have used feminised seeds, the sex is clear anyway.
Indoor plants that have been grown from seeds are sensibly and usually left in the growing phase for 4-6 weeks or until a height of 30-45 cm is reached. In the growing phase, the plants are always lit for 18 hours a day and always at the same time. Smaller plants can also be sent into flower, but this is less recommended for plants grown from seeds and more suitable for cuttings/clones. Some varieties show tendencies to develop sexual instability (hermaphrodites) if flowering is initiated too early.
4th flower:
Outdoor cannabis plants start flowering in late summer and early autumn. This is when the nights get longer and the days shorter. This signals to the marijuana plants that their life cycle is now slowly coming to an end. Sativas, indicas and their hybrids need the change in lighting time to start flowering, all autoflowering strains are independent of this and start flowering automatically after a certain time (usually after 4-5 weeks). Indoors, marijuana plants start flowering when the daily lighting time is reduced from 18 hours to 12 hours. After the change of light it takes a few days and then the first flowering can be seen.
The unpollinated female cannabis plants(sinsemilla = without seeds) produce flowers(material), resin, trichomes and cannabinoids throughout the flowering period. They also produce their distinctive terpenes, which give the plants and flowers their typical, varied and intense smell.
After weeks of heavy flower production, the peak of cannabinoid production and other metabolic processes is reached. At this point is the ideal harvest time. No or hardly any new flowers are formed, the buds have a maximum resin coating. The flowering time depends on the variety and lasts about 7-10 weeks for Indicas and Indica dominant varieties, while it can last up to 13 weeks for Sativas and Hazes.
With outdoor and greenhouse plants, cannabis can easily stay in the growing phase for several months. Outdoor cannabis plants with a long growing period grow 1.5-8m tall. Their yield is correspondingly large.
You can find more detailed information about the life cycle of cannabis in our Growing tips in the sections
- Seeds & Germination
- Growth phase
- Flowering phase
- Harvest & Processing