Marijuana light cycle: 12 hours a day
Seed germination length: 3-10 days
It’s important to know these stages and how long each lasts to know what the plant needs and when. Knowing where your cannabis plants are in their life cycle will dictate when to prune, train, and trellis your plants, and when to harvest.
The flowering stage is the final stage of growth for a cannabis plant. This is when plants start to develop resinous buds and your hard work will be realized. Most strains flower in 8-9 weeks, but some can take even longer, especially some sativas.
As roots develop, the stalk will rise and you’ll begin to see the first iconic fan leaves grow, at which point your cannabis plant can be considered a seedling.
Vegetative plants appreciate healthy soil with nutrients. Feed them with a higher level of nitrogen at this stage.
If you’re growing weed indoors, you can grow whenever you like. Keep in mind that the outside environment will affect your grow space—you may need to add heaters in the winter or fans and ACs in the summer. Other than that, you can start seeds whenever you like and flip them into flower whenever you like, depending on how big you want the plants.
By the start of week five, you will notice buds beginning to emerge whilst lush leaves continue to grow and develop. Nitrogen is the most important chemical element for your babies at this stage when their growth rate will dramatically increase. You will want them to grow horizontally as well as vertically, so it is vital that they have the right fuel to do so. You might be tempted to add flowering nutrients at this point but try and hold back as doing so prematurely will significantly impact the eventual yield if the plants aren’t allowed to grow to their maximum capacity.
Week 6 arrives, and more and more buds start to emerge. Allow the buds greater access to light by defoliation – the removal of wing leaves – or by gently tucking the wing leaves back, which is a less invasive method as the plants need their leaves for nutrients. Continue with vegetative phase nutrients.
During the first week, the seedlings don’t need any additional nutrients, Just ensure the soil is kept nice and moist, possible by using a water mister. Be very careful when watering as a sudden gush of water could wash the seedlings away. It is also important not to overwater as the developing root systems of the seedlings are also incredibly delicate.
In Week Two, you will hopefully observe the seedlings growing more vigorous with each passing day. Now is the time to introduce some mild nutrients unless you are using compost with pre-added nutrients. Place the lights a little closer to the plants if you notice that they are looking a bit lanky.
4. The next two weeks – 4 to 6
Growing cannabis isn’t as simple as germinating seeds, adding fertilizer and watering regularly. You have to do a bit of research and learn as much as you can about the growing stages of each variety. Autoflowers are a type of feminized cannabis with Ruderalis genetics. Put simply; this means that you don’t have to alter the lighting schedule to put them into the flowering stage – they do that by themselves. To enjoy a successful autoflower harvest, you will need to understand the science behind the autoflower life cycle.
You could also use starter cubes, or simply plant your autoflowering weed seeds directly into the soil. This might actually be the best method for germinating autoflowers as they do not like to be repotted.
During the last week, which may be anything from week 8 to week 12 for most varieties of autos – all the leaves will turn yellow, and the pistils may also change color. These are all signs that it is time to harvest. You can cut the leaves before the buds, a method known as wet trimming, or cut the whole lot at once which is known as dry trimming. It is a matter of personal preference, but the wet trimming method is the preferred choice of most cultivators as it is surprisingly difficult to separate the leaves from the stem once they have dried. Use gloves and sterilized scissors when harvesting cannabis to prevent infection and to avoid your hands becoming coated in sticky resin.
By this point, vertical growth has ceased, and you will have made the switch to flowering nutrients. The buds will start to grow expansively and become hard and dense. Pistils will begin to change color from white to amber, orange, to red. You will also notice that the plants have a much more pungent smell; hints of the harvest that lie in store. Toward the end of this stage, the fan leaves will start to turn yellow around the edges. This is an indication that the weed plants are approaching the end of their life cycle.