The Light Cycle for Cannabis Growth & Yield

What to Know About The Light Cycle for Cannabis Growth & Yield

When it comes to growing cannabis plants, proper lighting is an important part of the overall process. This is because the light cycle for flowering cannabis directly affects your crop’s quality and yield. With an appropriate light cycle, you can expect your cannabis plant to grow healthily and yield a good harvest in time.

In this article, we will share what you need to know about the light cycle in cannabis growth and yield.

The two stages of cannabis growth

Now, let’s look at the most crucial stages for monitoring the light cycles of your cannabis growth. Take note of the following details:

  • Vegetative stage light cycle: This stage is where the stems and leaves of the marijuana plants grow larger and taller, but they do not produce any buds yet. To help you control its size and yield, you must first control the lighting of the crops. The more lighting it receives, the better it will grow. The cannabis plants in the vegetative stage must be exposed to a minimum of 18 hours of growing light (18/6). However, growers may also keep the plants under 24 hours of indoor light (24/0) for their maximum size. Cannabis plants start to develop flowers when kept for 12 hours in continuous darkness. But if you want your cannabis plants to grow bigger, keep them under the light daily for about 13 hours.
  • Flowering stage light cycle: Your cannabis plants may have already transitioned from the vegetative stage to the flowering stage at this point. As a rule of thumb, they need to be exposed to 12 or more hours of darkness each day to induce the flowering. For proper budding, they must not be exposed to any light during these 12 hours of darkness. As the plants start flowering, they will continue to grow. While the darkness prompts the budding, rest assured that it will not stop the plants from growing. In fact, your plants may even double up in shape and size after the flowering stage. In two to four months* of transition, the cannabis plants will be ready for harvest.

What to know about outdoor or indoor light

With the choice of growing your cannabis plants indoor or outdoor, understanding light cycles for cannabis seeds in both scenarios can define the best light schedule for your crop to yield a good harvest. Here’s what you need to know:

  • Indoor light: Be sure to consider the room height or space to provide sufficient growth of your plant under a 24/0 or 18/6 light schedule during the vegetative stage. This lighting setup should last for approximately 60 days* before they are primed to grow flowers.
  • Outdoor light: Be sure to consider the interplay between natural light and artificial light for the outdoor growth of flowering cannabis. While the plants must be scheduled for 18/6 to start, always remember to avoid unfavourable conditions such as freezing temperatures and frost. Once clear from frost, the crops can resume their growth under the open atmosphere and sunlight.


At this point, you now know how important the light cycle is for your cannabis plants. To that end, remember to consider all the valuable information on its two stages—the vegetative stage and the flowering stage. Also, be sure to factor in how the indoor and outdoor light can affect the growth of your plants because the light cycle is instrumental to the growth and yield of your cannabis plants!

Here at Coffee Shop Seeds, we have a vast selection of premium CBD seeds in the UK for your cannabis plant growth. If you’re looking for cannabis seeds for sale, get in touch with us today to learn more about our products!

*Lighting and harvest times will be strain specific.

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