How To Nov 5, 2019

How to Transition Cannabis from Veg to Flower With LEDs

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Your cannabis crop is looking great as it completes the vegetative stage – uniform structure, robust size, pest and pathogen-free. Now it’s time to switch from veg to flower!

Many growers run into issues when flipping their veg room to flower. Keep your crop healthy and avoid shock damage by gradually transitioning your plants from their vegetative to flowering lighting conditions. Do this by incrementally increasing light levels and limiting cultivation changes to as few variables as possible.

If your LEDs are integrated with a lighting control software like smartPAR™, you can program your lights to increase intensity incrementally until you reach your maximum flower light intensity.

STEP 1: Adjust to 12-Hour Photoperiod

For the first 1-2 days in flowering, just let your plants get used to the new 12-hour photoperiod. Leave light intensity the same as what they were exposed to in the vegetative stage.

STEP 2: Begin to Increase Light Intensity

After the plants are acclimated to their new photoperiod, you can begin gradually increasing light intensity by about 10% every 1-2 days.

STEP 3: Repeat Until Ideal Light Intensity Reached

Once your light intensity has reached the level you want for flower and your plants are happy, let them do their thing! At this stage, you can adjust other environmental variables as needed. Keep in mind that any cultivation changes can impact plant performance as you transition your crop through its life stages. Try to minimize the number of changes you make at any one time to maintain your crop’s health.

Are your plants showing signs of stress?

Signs of stress can manifest as leaf drop, chlorosis (yellowing) of leaves, reddening of leaves, drooping leaves and slow growth. If your crop is showing signs of stress while you make the transition to higher light intensities, lower the light intensity and make more frequent lower intensity increases to complete the transition.

OVERVIEW: How to Transition Your Crop from Vegetative to Flower

Chart of how to adjust environmental factors when transitioning cannabis from veg to flower
Source: LumiGrow’s LED Growers’ Guide for Cannabis


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