Positioning LED Grow Lighting for All Stages of Marijuana Growth

Jul 08, 2021

Lighting is one of the most critical factors in growing marijuana. Understanding how close or far away to position the light source from marijuana plants is essential to produce a healthy plant and maximum yield.

Seedling Stage

For marijuana seedlings, LED grow lights should be between 24-36 inches above the plant canopy (a plant canopy is: the tallest branches of foliage of your marijuana plants). Seedlings are delicate, and placing lighting closer can cause bleaching or stunted growth. Placing the light source at this height also avoids drying out the soil. At the seedling stage, less light intensity is best.

Vegetative Stage

When marijuana is in the vegetative stage, it needs more intense light. The marijuana needs to build strong, healthy roots and stems to produce a productive harvest. Grow lights should hang closer to the marijuana plant canopy. The LED grow lights should be between 12-24 inches from the top foliage of your marijuana canopy. Monitor the plants closely to make sure they have enough light and not too much, which can cause adverse effects such as bleaching, discoloration, stunted or irregular growth. These effects can be addressed by adjusting the height of the LED grow lights.

Flowering Stage

The flowering stage is the final stage of “growth” for the marijuana plant. It is during this stage that flowering and fruit production occurs. During the marijuana flowering stage, the LED grow lights should be between 16-36 inches above the marijuana plant canopy. To transition plants from the vegetative to the flowering stage, it is best to gradually raise the LED grow lights to the desired distance for your specific marijuana crop height and flowering needs.

LED Grow Lights and Clones

Cloning marijuana plants is the process of taking cuttings from mature marijuana plants and re-planting them. These cuttings are not seeds, and require treatment much like vegetive plants. Place the LED grow lights between 12-24 inches away from the marijuana plant canopy. Keep in mind that they do not have a root base yet and need to establish that root base. It is best to start your LED grow lights further away and slowly work closer to establish that root base. Clones need to be observed closely for any adverse effects, as discussed earlier.