Medicinal Cannabis Flowering Stage

MEDICINAL CANNABIS CULTIVATION & PRODUCTION

03 - Flowering

Medicinal Cannabis Flowering Stage

Flowering

Flowering is the 3rd stage of the 12 stage medicinal cannabis production process. The first 1 to 3 weeks of the flowering stage are a transition phase, during which the plants could double in height. After the buds appear the plant will stop growing and will put all its energy into the flowers and the cannabinoids.

Optimum flowering conditions

Cannabis plants start flowering when they are exposed to equal hours of night and day. Prior to this stage, the plants should be given 18+ hours of light to encourage maximum growth. A facility control system such as Argus or Priva, gradually change the light cycle until a 50/50 ratio is reached. The system could also change the spectra of LED lights between the vegetative and flowering phases.

As the flower house is where the plants spend most of their time (60-70 days), it’s important to optimize all conditions. Cultivars that have a 60 day flowering period will typically deliver six crops per year. Achieving the highest yield of both flower volume and concentration of the active ingredients are highly dependent on the strain, the skill of the grower and the conditions in the flower house. Light, temperature, humidity and CO2 levels must all be precisely controlled through the facility control system.

In this graphic, there is an optimal temperature for photosynthesis.

In this graphic, plant growth will be constrained to poorest condition or nutrient.

Flower house processes

The flowering stage is very labour-intensive. Physically moving the plants between the vegetative stage and the flowering stage areas presents many manual handling issues. The process should be carefully designed to use as much automation as possible, both to keep labour costs down and to prevent injuries to workers.

During the 60-70 day flowering phase, a visual inspection of the plants to check for diseases, pests and general health should be done up to three times a day. Workers must also manually train the plants onto support structures. This prevents the plants collapsing under the weight of the flowers. The support structure also ensures good air circulation through the plants, which reduces the risk of disease.

Each cannabis strain requires different lighting for optimum growth and consideration must be given to all sources of light in the facility – including illuminated exit signage and task-based lighting used by workers, usually green.

Regulations

The propagation of cannabis plants is regulated by the Australian Office of Drug Control. You must hold a licence from them to cultivate cannabis (they control the plant during its lifecycle). Once the plant has been harvested and moves into the manufacturing stage of the final medicinal product then the Australian Therapeutic Goods Administration (TGA) regulations could apply. This part of the manufacturing process must comply with the current Good Manufacturing Practice guidelines. These rules are designed to ensure the safety and efficacy of all pharmaceutical drugs sold. The rules cover everything from facility design through manufacturing processes to the packaging, labeling, storage and transport of the final drug product.

Facility design

When designing the flower house of a medicinal cannabis facility, it’s important to consider:

  • Whether to grow under glass, under plastic or indoors: Growing indoors allows you to control all the conditions to achieve the best crop, but must be offset against the capital cost of setting up the facility. Growing under glass / poly-carbonate provides the most control but is also the most expensive facility to build.
  • Whether to purpose-build a facility or to retrofit an existing plant propagation facility. PharmOut has strong opinions on this one – based on experience!
  • All light sources in the flower house. Even exposure to illuminated signage of the wrong type or light from a worker’s torch can be enough to impact the plants.

Services PharmOut offers:

PharmOut can design a complete turn-key solution, or you may need help with only specific areas, such as:

  • Design of the flower house
  • Design of the workflows and processes to minimise labour costs
  • Design of personnel, material, waste flows and contamination control strategies
  • Design of the required security system
  • Selection of equipment and staff