Outdoor Grower's Guide to Flowering and Harvesting

People have been growing Cannabis plants for as long as we’ve known about its psychoactive properties. In fact, we have evidence showing that even 2,500 years ago*, the peoples of Central Asia were cultivating and consuming marijuana. In more recent decades, cannabis cultivation has had to take place undercover, occupying the closets and backyard corners of industrious growers, who had to learn the science of growth in secret. However, now that Cannabis has become legalized in Canada, more Ontarians are learning to grow the plant for themselves, whether that be for personalized use, or for larger-scale operations looking to go commercial, and are able to grow outdoors with confidence.

At Hydrotech Hydroponics, we often get asked questions about various steps of the growth and harvesting processes. This article is for the outdoor grower, whose plants will flourish with the ebb and flow of the seasons, and focuses on flowering: When will my plants flower? How do I know when they’re ready for harvesting? How do I trim and harvest the flowers? Home growers in Ontario, or any similar climate, will be able to apply this information to operations of any scale.


Female Cannabis Plant


When Will My Plants Flower?

Firstly, Cannabis plants can be either male or female. Both are important for certain kinds of cultivation, but for harvesting flowers, it is the female plants we will be looking at. Cannabis plants are annual, meaning they live and die in one growing season, which runs from summer to fall. At about the halfway point, as the long days of summer begin to shorten, your plant will begin flowering. Most strains will begin this process by August 15, though sometimes a bit sooner. However, some stubborn sativa strains won’t show flowers until September, so it varies a little from plant to plant. 


Close up photo of Cannabis Flower


When Will My Plants be Ready for Harvest?

The flowering period for different strains and growing situations will vary a little, but is generally between 5 and 9 weeks, and averages at around 7. When growing outdoors, this typically means your plant will be harvest-ready by the end of September. The plant has several indicators to keep an eye on during this time: the pistils, and the trichomes.

Pistils are the sex organs of the female cannabis plant and appear as small white hairs that cover the calyx (this is the case of modified leaves that the flower emerges from). In a sensimilla, or unfertilized plant, the pistils turn darker as the plant matures, becoming amber or reddish in colour when the flower is ready to be harvested. 

Trichomes are the sticky, shiny, mushroom-shaped protrusions that give the flower its crystalline appearance. Depending on the strain, the trichomes start out clear, but will turn a milky, or amber-ish colour as the flower matures. Once approximately 70% of the trichomes have changed colour, the flower is ready to be harvested.


Photo of cannabis plant


How do I Harvest?

After months of love and care, harvesting can be a bittersweet time for growers; it’s time to say goodbye to this year’s plants. Once ready to harvest, cut the plant at its very base, and prepare it for trimming and drying. If you are using soil or pots to grow and wish to re-use the growing media, remove the root mass from the soil immediately as well. It’s best to wear gloves during this process as the plant will be very sticky (nitrile gloves work very well).


Harvested and dried cannabis flower

How Do I Trim and Dry My Harvest?

Once harvested, it’s time to trim the plant. First, you’ll want to separate the buds from the main branches and fan leaves. The leaves and branches can be used to make extracts, but they’re not the main attraction here. All that work has come to fruition in the buds. Once these are isolated, they need to be trimmed, and this can be done in two ways:

Wet trimming occurs before the plant has been dried. It is an easier and less exhausting method and involves finely cutting away the leaves surrounding the bud with scissors, before the plant has been dried.

Dry trimming occurs after the plant has been dried. With this method, you would first do a rough wet trim, leaving the sugar leaves on the buds to protect them during the drying process. Once dried, these tiny leaves are trimmed off during a second dry trim. While more time consuming, this method protects the buds somewhat better than the quicker wet trimming method.

Growing your own cannabis is an art form, and can be hugely rewarding when armed with the right tools and knowledge. Luckily, we at Hydrotech Hydroponics have amassed what people have been learning for millennia about cultivating and harvesting, so that anybody can grow their own quality cannabis from scratch.

Check out our website and Instagram for more information, and stay tuned for more shared wisdom. Until then, happy growing, and don’t hesitate to reach out with any questions or comments. 




 * Earliest Evidence of People "Smoking" Weed Found in 2,500-Year-Old Chinese Pots