When growing cannabis, it is important to recognise and understand the stages of growth in the plant's life cycle, as at every stage the type of care changes. The various stages require different amounts of water, nutrients, and light. The way in which the plant is pruned and the determining of the sex and health also depends on the different stages.
There are four stages to the plant’s life cycle, and those are; germination, seedling, vegetative, and flowering.
Germination (weeks 1-2)
The seed is the initial stage of the cannabis plant, which at this stage is dormant. The quality of the seed is evident in its texture and colour, which should be firm, dry, and of a brown colour. If the seed is unhealthy it will usually be soft and of a green or white colour, and more likely will not germinate.
The next stage for the seed is germination which can take from 24 hours to 7 days.
When the taproot emerges, the plant is ready to be arranged into its growing pot. At this stage, two rounded cotyledon leaves will grow as the plant begins to shed the shell of the seed. These cotyledon leaves are what absorbs the sunlight that is needed to create a healthy and sturdy plant. At this time as the roots continue to grow, the first fan leaves will start to show, and at this stage, the plant is considered a seedling.
Seedling (weeks 2-3); 18-24 hours of sunlight
As the plant develops into a seedling, the more conventional cannabis leaves appear, although the leaves that materialise will only have one ridged finger. As growth continues the leaves develop more fingers.
Mature plants usually have 5-7 fingers per leaf, therefore until the leaves grow a full number of fingers, it is still considered a seedling. At this seedling stage, the plant should be short with a concentrated amount of vegetation. It should also be a vivid green and should not look like it is reaching for the sun. It is also important not to overwater the plant as the roots are small and therefore little water is needed for it to flourish.
The plant is also vulnerable to disease and mould, so it is important to keep its environment clean and be aware of excess moisture.
Vegetative (weeks 2-8); 13-24 hours of sunlight
This stage is when the grower will have moved the cannabis to a larger pot, and the roots and leafage will be growing at a fast rate. This is when the grower should start to top and train the plant.
The grower will also be able to determine which type of cannabis is growing by the space between the nodes. The Broad Leaf Drug variety plant is usually short and dense, while Narrow Leaf Drug variety grow tall and have less concentrated leafage.
As it grows the amount of watering should be increased. At the early stages, the plant needs water closer to the stalk, but as it grows it should be watered away from the stalk, so the root tips can absorb it better.
At this vegetation stage, the plants need healthy nutrient-dense soils and therefore need higher levels of nitrogen.
As the plant approaches its flowering stage, the sex of the plant can be determined according to the pre-flower. Female pre-flowers have two hair-like pistils developing on the buds, whereas if it is male it will have little pollen sacs. The further the plant develops the clearer the sex of it becomes.
If the cannabis is not for breeding, the males should be separated from the flowering females to prevent pollination.
Flowering (weeks 6-8); 12 hours of sunlight
This is the final stage of the plant’s growth cycle, and flowering usually happens naturally once it is receiving no more than 12 hours of light a day.
This is also the stage where resinous buds are produced.
There are important changes that need to be utilised during the vegetative stage to the flowering stage, and those are;
- It should be pruned no later than two weeks into the flowering stage as it can affect the hormones
- It should be trellised and staked, to support the growing buds
- Consider feeding it with more nutrients and stop increasing the amount of watering.
As soon as the buds reach maturity, this is the time to harvest.