After sowing seeds, you’ll watch your cannabis plants become seedlings, surge through the vegetative phase, and become mature flower-bearing specimens. Discover the details of these key stages of growth. You’ll find out exactly what your plants need during each phase, and how to correctly harvest and process them afterward.
Growing cannabis consists of five major phases. During each one, the plant has slightly different demands that growers need to cater to in order to produce the best results. Of course, every cultivator does things differently and develops its own preferences over time. However, there are a few non-negotiable needs that plants have during each stage of the growing cycle.
After you buy cannabis seeds, check out the journey of a weed plant below to find out how a cannabis seed develops into a mature and harvest-ready specimen.
Watching your cannabis seeds germinate really gets the excitement going! When exposed to darkness and dampness, cannabis seeds activate. Within the next 1–7 days, they’ll put a taproot down into the soil and a green shoot up into the air.
Place your seeds between two wet paper towels to create a humid microclimate ideal for germination. If you really want to maximize germination rates, use a specifically designed starter kit to treat your cannabis seeds to optimal humidity and beneficial microbes.
Following germination, plants enter the seedling stage. You’ll need to transplant your specimens into a larger container. We recommend placing your seedlings directly into their final pot—11L fabric pots work great—to avoid transplant stress and slowed growth later down the line.
Your seedlings require good lighting at this stage. Position them below high-quality LED grow lights and keep them running for at least 18 hours per day. Aim for a relative humidity of 70% and a consistent temperature of 20–25°C. You can use a thermo-hygrometer to monitor these parameters, and heaters and humidifiers to modulate them.
Seedlings don’t need much water. Just make sure they aren’t completely bone dry. Overwatering kills many seedlings by causing damping-off, a fungal disease. Go easy on the liquids.
The seedling stage takes place over 1–2 weeks.
During the vegetative phase, plants begin to develop large root systems that secure them to the ground and luscious fan leaves that generate energy and drive growth. They need plenty of light at this stage, so maintain a cycle of at least 18 hours on and 6 hours off.
As they surge in growth, plants burn through nutrients. You’ll need to add a specialized vegetative formula high in nitrogen to keep them thriving.
Your plants will become thirsty during vegging, but overwatering can still cause some real damage. Only water once the top inch of soil becomes completely dry.
Reduce humidity to 50% to decrease the risk of fungal disease, and maintain a temperature of 20–24°C.
Training during the vegetative phase will enhance airflow in the canopy, reduce mold, and optimize yields. Low-stress training is a simple way to shape and control your plants.
Use soft garden ties to pin down the tip of your plant to the rim of the pot, and allow the side branches to shoot up and create a dense and fruitful canopy.
We recommend placing a gentle fan in your growing space during this time. The breeze will cause your plants’ roots to strengthen their hold and will make their stems and branches stronger.
The vegetative phase lasts around 4 weeks in auto-flowering plants, whereas photoperiod plants can remain in vegetation indefinitely. Growers can shift into flowering by changing the light cycle to 12 hours on and 12 hours off whenever they like. In other words, the veg stage can last anywhere between 1 week and several months with photoperiod plants.
Now things are starting to get exciting! Because feminized seeds don’t produce males, you won’t need to waste time and resources sexing plants and removing males from the growing space.
You’ll start to see flowers appear at the nodes—the points at which the main stem and branches conjoin.
Flowering plants have a different appetite than vegging specimens. Use a flowering nutrient formula higher in potassium and phosphorus to boost flower development.
Reduce humidity to 40% at the start of the flowering stage. This will help to keep mold away, as the compact and damp nature of cannabis flowers creates a safe haven for fungi. Maintain a wider temperature range of 20 – 28°C.
Use trimming scissors to defoliate excess fan leaves from within the canopy. This will ensure all flowers receive adequate light and airflow.
Overall, flowering takes between 6–12 weeks depending on the cultivar. Stop applying nutrients 2 weeks before harvest time. Known as flushing, this will remove excess nutrients from the flowers and make them taste much better.
You made it! But how do you know exactly when to harvest? Use a microscope or loupe! Take a close look at the trichomes—those small crystals that produce all of the good stuff—and make sure they look milkier than they do translucent.
When they look ready, use a pair of trimming scissors to remove them from the branches, and trim away all of the small sugar leaves.
Harvest time might feel like the end of the operation, but there’s still a ways to go. You’ll need to properly dry and cure your buds to prevent mould, improve the taste, and prolong their shelf-life.
Place your buds on drying racks in a warm room with a fan on to speed up the process. Once nice and dry, place them in jars to cure for 2–8 weeks. Open the jars for a few minutes every day for the first two weeks, and then only twice per week after this.
Curing will help to remove the moisture from inside cannabis flowers, vastly improve their taste, and make them smoother to smoke. Enjoy!