2019 was the first year for legally growing cannabis in Ontario for personal use.  Cannabis became legal in October 2018 and is available to purchase in many outlets across Ontario but many prefer to grow a few plants.

Rules and regulations for the Government of Canada Legislation on cannabis can be found at https://www.justice.gc.ca/eng/cj-jp/cannabis/  

Each province has its own set of guidelines.  In Ontario, adults are allowed to grow four cannabis plants per household for recreational use.   If you rent or live in a condo you should check your lease or condo rules. 

Even though it is considered by some to be a “weed” there are quite a few things to remember when growing cannabis.   There are many experts who have grown cannabis for years and everyone has their own methods to grow a great crop.  There are many reasons to grow your own cannabis, anonymity, personal satisfaction, control of strain, nutrients, and final product.

You can also save money because one plant can produce up to 500 grams of cannabis.

Step one to Growing Cannabis in Ontario:  Choose a Strain 

Cannabis is an annual flowering plant that comes from the genus Cannabaceae.  There are three species in the genus – Cannabis indicia, Cannabis sativa, and Cannabis ruderalis.  Ruderalis is not very common and Sativa varieties are difficult to grow outdoors as they require a much longer growing period.  There are over 700 strains of cannabis with new strains being developed every year so choosing can be difficult.

Here is a checklist to get a great strain to growing cannabis in Ontario outdoors:

  1. Autoflowering strain. This strain will automatically flower after a short vegetative period because it is not reliant on light. These strains contain some genetics of the Ruderalis species.
  2. Feminized seeds.  Cannabis is a dioecious plant meaning only female unpollinated plants produce buds. Most seed vendors offer feminized seeds.
  3. Is the strain you are choosing being grown in our climate zone? Choose one that is commonly grown in Ontario.
  4. Choose a strain for desired effects. Indicia affects the body and has more sedative properties, Sativa strains are more uplifting and euphoric.  Although Sativa species are not recommended for outdoor growing there are many hybrids that are a combination of the two with a shorter growing period.

Seeds are not readily available but can be found in a few places.  You can purchase online from Canadian seed vendors, or from a few seed stores.

Step 2 – Seed Starting seed trays with plugs

Cannabis needs to be started indoors around the same time you start your tomatoes, approximately 6 – 8 weeks before the last frost date.  In London, Ontario our last average frost date is May 10th.  I wait until after the holiday weekend to be sure.  If planted early and frost is expected you will need to cover the plant or bring it in to protect it.

In order to speed up germination, you will need to soak the seeds. This helps break down the seed coat and imitates spring conditions.  There are 2 ways to germinate your seeds.  The first is the paper towel method.  Place seeds on an inexpensive paper towel on a plate, keep moist, and cover.  Wait for seeds to sprout.  The second method to sprout seeds is to use peat pellets and place the seed directly in pellets.  Place pellets in a plastic seed container and place on a warmer pad and keep moist.  Sprouts should occur within 5 days.

Step 3 – Transplanttiny seedling being transplanted

Once your seeds have developed two true leaves it is time to transplant to a larger clean container.  Whatever container you choose make sure it can drain excess water and If reusing plastic containers make sure you wash in hot water with 10% bleach or 9 parts water and 1-part bleach.  This eliminates pathogens and can prevent dampening off.  If placing in the final container you will need at least a 10-gallon (45 liters) pot or grow bag, your cannabis will grow according to the size of the container. Place under grow light for at least 18 – 24 hours per day.  Make sure the light is not too far from the leaves or the seedling will become leggy.  Keep plant moist until it is ready to be “hardened off”.  A week before plants are to go outside you have to “harden them off”.  On the first day, place them for 2 hours in an area with partial shade.  Partial breeze is beneficial to strengthen branches and prevent mildew.  Add an hour every day, careful not too much sun – plants can burn.  After a week your plant is ready to live in the garden.

You need to decide if you will grow it in the ground or in a container? Do you want to be able to move the plant easily?   Whatever you choose make sure it’s a sunny location that’s not too windy.  When planting in a pot or container it is recommended to add organic fertilizers like worm castings, compost, and fish meal to the soil before planting and throughout the plant’s life cycle.   It is important to have light fluffy soil with lots of nutrients in it.   In this stage, it is important to provide Nitrogen to feed the leaves and stem.  Growing a few companion plants near your cannabis can be beneficial.  Rosemary, marigolds, and basil are great companions because they contain natural repellents that act as deterrents for pests.  Water regularly but do not overwater.  This is a good time to check to ensure your plant is female.

branch structure of female plant is quite distinct from the male

Left- Female. Right – Male

The growth stage can last until August.  This is when you top the plant if you want to create a bushier and wider plant that doesn’t get too tall.  Make sure you use clean tools and cut once 4 – 5 nodes appear.

Stage 4 – Blooming Phase

Around the middle to late August, hairs will begin to show, avoid touching them too much.  Your plant will require a bit more water.  You can now switch to bloom fertilizer or decrease Nitrogen and increase Phosphorus.  Bone meal is a good source of phosphorus.


 Stage 5 – Harvest      

Harvest could occur anytime between late September to early October, depending on the strain.  The fan leaves will start to yellow at the bottom and there will be a change in the hairs of the buds.  The pistils or hairs will turn brown.  Two weeks before harvest stop giving fertilizer and water normally.  To begin the harvest process cut the fan leaves away with clean scissors.  Let the plant dry out for several days.  Do not water.

Cut the flowers (also called colas) and hang them in a cool dark room upside down.  Coat hangers and clothesline clips work great.  Place an oscillating fan to speed up the process as this can take over a week.  You will know the plant is dry when the branches snap instead of bend.  Be patient, the drying and curing processes are important.  They allow cannabis to be more storable and improves taste.  Once the colas have dried, trim the buds and remove sticks and leaves.  Place in mason jars loosely until it 2/3 full.  Seal tightly and place in a cool dark space such as a closet.  In the 1st week, it is important to open your jars 3 times a day for 5 – 10 minutes.  This allows buds to breathe and replaces oxygen and allows moisture to escape.  The 2nd-week jars should only be opened every few days and allowed to breathe for 5-10 minutes and then tightly replace the lid and return jars to their cool, dark curing space.  Letting your cannabis jar cure for 2-3 weeks is usually enough time but curing up to 4-6 weeks can make the final product even better.

If you are not a smoker then you have to decarboxylate your cannabis.  Smoking creates a chemical reaction that occurs when cannabis is heated.  Heating removes a carboxylic acid group from the makeup of the herb, making it much more potent.  Drying and curing cannabis over time will cause a partial decarboxylation to occur but to fully decarboxylate cannabis:

Place ground cannabis on a baking sheet with parchment paper, remove any sticks.  Bake for 30 – 40 minutes in an oven set to 220-235 degrees.  Now your cannabis is ready to be used for making tinctures, butter, or salves.

Growing cannabis is a lengthy process but can be very rewarding and produce enough until the next harvest.

Lots and Lots of Resources for Growing Cannabis in Ontario!

Youtube – Growing Cannabis from Seed

What Do Marijuana Seeds Need to Germinate?

Cannabis is now Legal – Here’s What you Need to Know

Medical News Today – Everything you need to know about Cannabis

Drying and curing marijuana buds







everything you need to know about jar curing cannabis