Your carefully propagated young cannabis plants are rooted in the propagation area and ready to move to the vegetation room. Make the move stress-free for these young plants by gradually transitioning the light intensity from propagation to vegetative levels while minimizing environmental changes.
STEP 1: Transition to LED Spectrum
If you’re switching from a LED propagation environment to a LED veg environment, you won’t need to worry as much about this step.
If you grow young plants under T5 fluorescent or metal halide lights in propagation, the first step in the transition to the vegetative phase is to acclimate your plants to the enriched spectrum of LEDs. This is a relatively quick process, taking only one to two days. During this step, match the light intensity of your LEDs in your vegetative rooms with that of the propagation room. This step is only to transition to the new spectrum. All other environmental variables remain the same.
Average light intensity for cannabis propagation is between 100-200 μmol·m−2·s−1.
If you don’t know your propagation area’s light intensity, you’ll need to take light measurements for this step.
STEP 2: Begin to Increase Light Intensity
After your plants have acclimated to the LED spectrum, you can begin gradually increasing light intensity by 50% every 1-2 days. This allows for a gradual but timely transition. If you are growing more sensitive cultivars, you can increase the light intensity as slowly as every 7 days. If you are growing hardier cultivars, you can increase light intensity more quickly to complete the transition faster.
Each time you increase the light intensity, review the environmental settings and plants’ responses regularly. Gradually transition the other growing area conditions and settings to vegetative levels. If you spot anything of concern, slow down the transition period to minimize stress on your plants. Each transition period can be as long as 7 days.
STEP 3: Repeat Until Ideal Light Intensity Reached
Continue to increase your light intensity until you’ve reached the vegetative intensity level. The ideal light intensity for vegetative growth is 400-600 μmol·m−2·s−1. Once your light intensity has reached the level you want for veg and your plants are happy, let them veg away!
See the next article in this series, “How to Transition Cannabis from Veg to Flower”, to prepare for the transition from the vegetative to flowering stages.