How Many Hours of Light Do I Need for Cannabis Veg Growth?

How Many Hours of Light Do I Need for Cannabis Veg Growth?

How many hours of light do I need for cannabis veg growth

The process of growing cannabis, particularly during the cannabis veg stage, is a delicate one that demands meticulous attention to various factors. One such factor is the lighting, which plays a crucial role in the photosynthesis process during the vegetative stage of weed. This article will delve into the significance of light exposure, the optimal number of hours for cannabis veg growth, and provide tips for achieving the best results in growing cannabis.

The Importance of Light Exposure​

Light exposure is a critical component in the development of cannabis plants, especially during the vegetative state cannabis stage. In this vegetative state, plants need an adequate amount of light to build a robust, healthy structure that can support the weight of the flowers in the subsequent stages. Ensuring proper light exposure is key to helping your cannabis plant grow to its full potential.

Ideal Number of Hours for Cannabis Veg Growth​

In the vegetative stage, cannabis plants require more light exposure than in the flowering stage. The general guideline, especially when considering how long to veg weed, is to provide 18 hours of light and 6 hours of darkness. This photoperiod cannabis schedule mimics the natural light cycle in the summer months, promoting the plant to grow strong and produce abundant foliage.

Other Light Cycles to Consider​

While the 18/6 light cycle is the most common, there are other light schedules that some growers use during the vegetative stage, even for a 4 week veg. These alternative schedules offer different ways on how to veg your cannabis plants.

  • 20/4 light cycle: This schedule involves 20 hours of light and 4 hours of darkness. Some growers believe that the extra hours of light exposure can promote faster growth, but it may also increase the risk of plant stress.
  • 24/0 light cycle: This schedule provides cannabis plants with continuous light exposure. While it may speed up the growth process, it can also lead to increased energy costs and potential stress on your plants.

Tips for Optimizing Light Exposure​

Following these tips can help ensure your cannabis plants receive the appropriate amount of light during the vegetative growth stage, along with the best nutrients for veg stage. Providing the right veg stage nutrients or vegetative nutrients can significantly enhance the growth and health of your plants.

  1. Choose the right light source: Different types of grow lights have different light spectrums and intensities. High-intensity discharge (HID) lights, such as metal halide (MH) or high-pressure sodium (HPS), are popular choices for cannabis cultivation. However, more energy-efficient alternatives like LED and compact fluorescent lights (CFLs) are also suitable.
  2. Maintain proper light distance: The distance between your plants and the grow lights is crucial. If the lights are too close, they can cause heat stress and light burn. On the other hand, if they are too far away, the plants may not receive enough light. Adjust the distance according to the manufacturer's recommendations and monitor your plants for signs of stress.
  3. Monitor temperature and humidity: The ideal temperature range for cannabis vegetative growth is between 70-85°F (21-29°C). Excessive heat or humidity can lead to various problems, such as mold, pests, and nutrient deficiencies. Ensure your grow room has proper ventilation and climate control to maintain optimal conditions.
  4. Train your plants: Techniques like topping, low-stress training (LST), and screen of green (SCROG) can help maximize light exposure to all parts of your plants. These methods encourage bushier growth and increase the number of bud sites, resulting in a higher yield.
In conclusion, providing your cannabis plants with the right amount of light during the vegetative phase is essential for their overall health and development. An 18/6 light cycle is widely recommended, but alternative schedules can also be used depending on your specific needs and goals. By optimizing light exposure and maintaining proper growing conditions, including low stress training, you can ensure your cannabis plant reaches its full potential in growing cannabis.
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  • zhuk
  • 5.00 star(s)
Great info. I'm just amassing the bits & pieces needed to start growing and was wondering about how to combat heat in summer (in my case australia, and it gets hot! and will do in my intended grow area, esp as summer will be well on the way by December) So the lights off at the hottest times makes great sense ;)
  • Frankster
  • 5.00 star(s)
That said, I do 24 hours with it's really cool parts of the year, and can use the extra heating in the house, and warmth for the plants. I agree 18/6 has it's advantages. Would be cool to see one on this regarding flowering, and techniques to speed the ripening process along in some situations.
  • Hez
  • 5.00 star(s)
I keep mine on 24. What I use are the low watt (13) / 100 watt output "green energy" bulbs. Keeps my meter from spinning like a Frisbee on meth. Three bulbs seems to be more than enough light in a 10X10 room. Bonus is the bulbs have a 10 year life according to the package and guaranteed.
  • angeltrumpet
  • 5.00 star(s)
This is answer my question, I have my one seed under 18 hours light since 25th January, it is just coming to the 3rd set of leave,roots appearing through bottom of pot.I think to transplant to a bigger pot in a week , I want to delay flowering till its hopefully a dwarf conifer size and bushy, then take outside gradually increasing the natural sunlight hours knowing that it starts to flower, as I read on countless forums. This is my
first time with lights using a 50watt Led.
  • 5.00 star(s)
good advice
  • Flip3387
  • 5.00 star(s)
Not common sense to a beginner, answered my question.
  • hamphealth
  • 5.00 star(s)
Convinced me.
  • MrBulldops
  • 5.00 star(s)
That is a common sense answer!
  • burn4me
  • 5.00 star(s)
perfect explanation
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