Cannabis Plant Stages and Light

Feb 16, 2022

Quick Overview of Cannabis Growing Stages with Grow Lights

A growing cannabis plant has four main stages/life cycles: Germination, Seedling, Vegetative, and Flowering. Growing cannabis from seed to a mature plant can take anywhere between three-eight months, depending on the strain.

Cannabis Seed Germination Stage

The germination stage takes three to ten days. Start with healthy seeds. These should be hard and dry and light brown to dark brown. If the seeds do not look like this, chances are they will not germinate. It is best to start the seeds indoors for the best germination outcome. During the germination stage, cannabis seeds must be kept in the dark in a warm, damp, and humid environment. The seeds must be checked often to verify they are moist but not drowning.
When starting seeds using no medium (soil, peat, or coco), it is time to transfer the germinated seed to a growing medium when the taproot appears. When a plant emerges from the medium, it is now the seedling stage.
When germinating in a medium at the first sign of a plant emerging, it has moved into the seedling stage.

Seedling Stage – Introduce Blue Spectrum LED Light

The seedling stage takes about two to three weeks. The cannabis plants are very fragile, and it is essential not to overwater them. The plants need at least sixteen hours of light during the seedling stage, but eighteen is best with six hours of darkness. During the seedling stage, the LED blue light spectrum is preferred. Moist soil, high humidity, and eighteen hours of the LED blue light spectrum will ensure the rapid growth of cannabis. The LED blue light encourages root and leaf development to stabilize the plant as it grows bigger. Once the first true leaves grow, a leaf with five to seven blades, the cannabis plant then moves into the vegetative stage.

Vegetative Stage – Reduce the Amount of Light

The vegetative stage is from three to sixteen weeks long. The cannabis plants need between sixteen and eighteen hours of LED blue grow light spectrum. The vegetative stage is where the cannabis plant does all the development. The plant stem grows thicker and taller, and its root system is established, preparing to bloom. The plant grows taller and produces leaves and branches. During this time, the plants need more water and airflow. It is vital to allow the plants to dry out between watering to keep mold and mildew away and ensure they are not drowning. Giving the cannabis plants a substantial time in the vegetative stage will produce bigger plants and probably higher yields. Lighting is the key to encouraging cannabis plants to move into the flowering stage. Change the LED grow lights to twelve hours on and twelve hours a day off. This lighting change will trigger the plants to produce flowers.

Flowering Stage – Time for the Red Spectrum from your Grow Light

The flowering stage is from eight to eleven weeks long. During the flowering stage, the LED red grow light spectrum encourages flowering and the development of THC (the main active ingredient for a “high” in cannabis). Continued use of the twelve-hour LED red grow light schedule will produce the best results of THC. The flowering stage has three subcategories.

  1. First is flowering initiation, which can be from one to three weeks. The female cannabis plant pistils start to produce “white hairs” in this stage. By the end of the third week, buds will appear in clusters on the female plants.
  2. Second is the mid-flowering time which takes four to five weeks is where the buds fatten, the pistils begin to darken, and aromatic properties form.
  3. The third is the flowering/ripening of the buds, which takes six weeks or more. The buds grow trichomes that produce the resin containing cannabinoids, flavonoids, THC, and terpenes. These trichomes change color from clear/transparent to amber. When the trichomes turn a shade of amber is one indicator that the cannabis is ready for harvest.