What are the stages of cannabis plant growth?
As cannabis becomes more widely used both medicinally and recreationally, its legal cultivation is on the rise. Like all plants, cannabis plants pass through fairly distinct stages as they grow to maturation and the production of buds. There are four main stages of development in the life of a cannabis plant.
Seed germination can take between five and ten days for a cannabis plant. A plant requires about 18 hours of light at this time, either natural or artificial. Seeds that are developed enough to grow are typically hard, dry and brown. As the root reaches down, the stem will go up and sprout two leaves. Once ridged leaves appear, your plant is considered a seedling. Many industrial cannabis facilities start plants from cuttings of “mother plants” rather than from seeds, to better control the genetic identity of the plant.
"It's called a mother plant because it's producing basically children. It's producing young plants that will have the same characteristics as the mother,” Michael Camplin, general manager of CannTrust's Niagara-area cultivation facility, said.
Healthy seedlings will begin to grow the well-known ridged fan leaves. As the plant develops, it’s leaves will hold more blades in odd numbers, starting with one and increasing to five or seven. Eighteen hours of light are also necessary at this point. Seedlings are sensitive to overwatering, mold and disease. Plants will be seedlings for two or three weeks, and once the fan leaves have five blades or more, the plant enters the vegetative stage.
In the vegetative stage, which can last between three and sixteen weeks, the plant continues to require about 18 hours of light. Plants grow quickly during this time and will require more water. Pruning, training and topping practices are sometimes carried out during this period to influence the growth of the plant and in an effort to increase its yield.
To move a vegetative plant into a flowering stage, the amount of light must decrease to 12 hours daily.
"Marijuana plants are very light-sensitive, and they are triggered to go into flower when the day length shortens in nature, as the summer starts to turn into fall. The days get shorter, and the plant knows that it's time to reproduce,” Camplin said.
A few weeks into the flowering stage, plants will show their sex organs and male plants must be separated from females, so they don’t pollinate them. Female plants produce the buds that contain cannabinoids like THC and CBD. Many professional cannabis farms will only grow female plants. Plants can spend about seven to ten weeks in the flowering stage.
After the cannabis flowers, it is typically harvested and dried. It may also be lab-tested for quality. Some cannabis will go through a heating and extraction process to create the oil that can be used medicinally, before being packaged and sold.