This article is about the different stages of a Cannabis plant life cycle, week by week. On this page you’ll find information about the plant’s growth at each stage, basic needs and what to watch out for! 

A cannabis plant’s life cycle can be divided into four main stages:

  1. Germination stage;
  2. Seedling stage;
  3. Growth or vegetative stage;
  4. Flowering stage.

Each stage has its own environmental, photoperiodic and nutritional needs. Let’s find out all about the stages of cannabis plants…

Storing and preparing your Cannabis seeds


It all starts with a seed, that’s how the life of a cannabis plants begins. A viable seed looks brown with some stripes, dry and hard to the touch. If it feels weak or it’s white or light green, it’s probably an undeveloped seed and it won’t produce a healthy plant. These seeds will probably not germinate.

If you want to store your cannabis seeds, keep them in a dark, DRY, cold place, for example, in the fridge inside a plastic bag for better conservation. When you want to start growing from seeds, you should take them and let them adjust to room temperature before trying to germinate the seeds.

To improve your chances of successful germination, you can place your seed in a glass of water; if it stays afloat it’s probably not viable, although it may germinate anyway. If it sinks, it’s probably viable and full of life, ready to germinate. Do not leave your seeds in the water for longer than 24 hours, as the seed needs fresh oxygen, they may drown and die.

1. Germinating cannabis seeds

  • The germination of marijuana seeds can take between 3-10 days.
  • The appropriate temperature for germination is (21 to 26 °C)

Best Results
You will have the best results when you use premium cannabis seeds for your next grow. To germinate cannabis seeds, they need a couple of things: warm temperature, high humidity, fresh air and water. Place your cannabis seeds in a dark, warm, and humid place, for example between two plates in a damped cotton pads. 

Keep a close eye
When the cotton dries up, the activated seed opens up and starts showing the first white tap root, this tap root will start searching for water and something to hold onto, so keep an eye on it and don’t leave it in the cotton for too long.

Once the root is formed, it’s time to gently put it in its next growing medium (soil, coco, etc) in a small pot. After a few days, the tip of the stem emerges from the ground. After that, two cotyledons or seed lobes appear, ready to catch the first light. Your plant will now grow by photosynthesis. In the germination stage, your emerging cannabis plant needs 18 hours of sunlight every day.

Next stage
After this initial stage, your germinated seed turns into a seedling.

2. Seedling stage


At this point, your tiny germinated plant evolves into a seedling over a 2 to 3-week period.

Root, stem and leaf growth
When your marijuana plant becomes a seedling, the roots start to develop rapidly, and you’ll notice it developing more of the traditional cannabis fan leaves. As a sprout, the seed will initially produce leaves with only one ridged blade. Once new growth develops, the leaves will develop more blades (3, 5, 7, etc.). A mature cannabis plant will have between 5 or 7 blades per leaf, but some plants may have more.

Stage change
Cannabis plants are considered seedlings until they begin to develop leaves with the full number of blades on new fan leaves. A healthy seedling should be a vibrant green color. 

Be very careful to not overwater the plant in its seedling stage—its roots are so small, it doesn’t need much water to thrive.

At this stage, the plant is vulnerable to disease and mold. Keep its environment clean and monitor excess moisture. Be sure to give it plenty of light. If the seedlings don't reveice enough light, the stem will grow and grow to find light, resulting in a stretched seedling, which is easy to fall over because it's not strong enough. 

Outdoor = start indoor
Even if growing outdoors, a lot of growers will start their seeds inside under an artificial light to help them through this delicate stage of marijuana growth.

3. Vegetative Stage


Faster growth
This stage revolves most heavily around growing larger. Bigger plants need more soil to give their root system enough room. That is why you should transplant your plant to a larger pot at the start of the growth phase. This way you give the plant’s leaves and roots full freedom to develop.

Topping and LST
This is also the ideal time to begin topping or training your plants. In topping, you cut away the top end of the stem. This makes more energy available for lateral growth (branching out sideways, that is), allowing your plant to develop a greater number of buds.

Female or male
The end of the vegetative stage provides a vital opportunity to look for males in your crop. As plants leave this stage, the females will start developing two white pistils, where males will grow pollen sacs. If you see these sacs, remove the plant from the vicinity before it pollinates the females and ruins your harvest.

Grow Characteristics
In the vegetative stage you will be able to tell what kind of plants you’re growing as they show their defining characteristics. Sativas will become taller and narrower, whereas indicas will appear short and bushy with dense foliage.

Thirsty plants
Be mindful to increase your watering as the plant develops. When it’s young, your plant will need water close to the stalk, but as it grows the roots will also grow outward, so start watering further away from the stalk in the soil so roots can stretch out and absorb water more efficiently. 

Your plants will also become more thirsty as its root system matures. Keep watering copiously, but don’t overdo it. Check the soil moisture level to prevent the onset of fungi and rot. Beyond that, let your plant do the work. Make sure it stays comfortable, with enough-but-not-too-much water and nutrients, and enjoy watching how cannabis grows. Next up is the flowering stage.

4. Flowering stage


Short overview of the most important things to keep in mind during this stage:

  • Warm temperature, around (18 – 26º C) 
  • Relative humidity: around 40-50%.
  • Higher light intensity, red spectrum preferred
  • Adequate light distance: hand test
  • Light/Photoperiod: 12 hours of light / 12 hours of complete darkness (very important.
  • Nutrition: a higher dosage of flowering nutrients
  • Watering: Water as needed
  • pH levels: between 6 and 7
  • EC : around 2.0

Flowering time
The duration of the flowering stage varies among different strains. Usually anywhere between 8 to 11 weeks, depending on the strain. The flowering period for Indica strains is typically around 8 weeks, but it may take up to 10 weeks. Sativa strains may take up to 10-12 weeks. Typically, hybrid strains will take up to 6-10 weeks to fully develop.

Important note
It’s extremely important NOT TO INTERRUPT the hours of darkness (lights off) for the plant to start flowering correctly. If this dark period is interrupted, the plant gets “confused” and flowering may be delayed or worse, the plant may revegetate (go back to veg stage) or start producing hermaphrodite flowers. You definitely don’t want that to happen!

Indoor grow
If your plants are growing indoors, the flowering stage will be initiated by switching the timer for your lights to 12 hours of light and 12 hours of darkness. For indoor growers, ventilation is key in preventing fungi and other unwelcome guests, as is a clean growing environment. It would be a shame if your harvest was to fail this close to the finish line. 

Outdoor grow
If your plants are growing outside, this stage is initiated by the shortening of the days after the summer solstice has passed. At this stage, the cannabis plants only require 12 hours of light each day. 

Autoflower cannabis plants
Autoflowering strains don’t need a photoperiod change to start flowering, their vegetative stage lasts around 4 weeks and then it changes stages automatically.

Check for males
The onset of flowering is your last chance to remove any males or hermaphrodites before they ruin your females. Stay on the lookout for these!

Bud development
In this stage, female plants start to develop their calyxes or flower buds. The white ‘hairs’ on the buds are pistils, revealing your plant as feminine. These flower buds will soon be full of glistening trichomes. Trichomes are the tiny glands containing the resin that carries the most cannabinoids like THC and CBD. They also carry the terpenes that give your plant its unique scent, taste, and subtle effects. This is the fruit of your labour; the result you’ve been investing all your time and effort in.

Buds typically grow the most toward the end of the flowering life cycle. You probably won’t notice much budding out at the beginning of the flowering stage, and it will slow down toward the end of the cycle, when buds become fully formed.

When to harvest
Many growers find it hard to determine when their weed plant is ready to harvest. It can be difficult to stay patient and wait, but your crop yields will only get better! You can see when a plant is nearly ready to harvest once the trichomes go from transparent to milky white and opaque. Get a microscope from our accessories to see your trichomes in full glory. The pistils of the flowers are another sign. By the time these pistils start to curl inwards towards the bud and turn golden brown, it’s almost harvest time.

During and after harvest
Once you start to harvest, you’ll still need to trim your buds to remove any excess plant material without THC or CBD. In addition, harvested buds need to dry and then cure to attain perfect taste and potency. Just like good wine or cheese – it takes time. We will discuss these steps in separate blogs. For now, at least you know the stages of how cannabis plants grow.

Keeping your cannabis plants healthy is important

When growing any plant, you want it to be healthy. The main reason is that a healthy plant is easier to grow and more forgiving. When growing a weed plant, the need for a healthy environment is even more critical for it to have the best possible results. You will probably be consuming the buds produced by your weed plant, and of course you want those buds to be the absolute best.

Good news: Anyone can successfully grow a healthy marijuana plant with a good harvest. Everybody can become an expert grower, but is a combination of the right knowledge, practice and experience. Do your research and learn everything that you possibly can before you start growing. Then apply that knowledge to your weed plants.

With a lot of patience and practice, you will get more experience and your plants will get better with every harvest.

Other questions?

Contact us and we will help you further!

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