Under canopy lights / side lighting can be used to maximize light exposure to cannabis crops, pushing yields to their peak and getting even those stubborn buds lower down on the plant to grow fat. However, this is only advantageous if all other environmental metrics are satisfied. Though simple in itself, additional lighting is best suited to advanced growers. Keep reading to find out why, and to find out how to utilize additional lighting for growing weed.
Benefits of Under-Canopy Lighting:
Uniform Light Distribution:
Placing lights below the canopy of a cannabis grow, or lighting it from the side, can help to maximize yields and generally improve plant health by ensuring all parts of the plant are exposed to adequate amounts of light.
Apical Dominance:
Cannabis plants exhibit apical dominance anyway, meaning that the main cola grows at the very top of the plant—because in nature this is most likely to catch pollen drifting on the wind. When growing indoors, lighting that sits permanently above plants can exacerbate this imbalance, meaning lower bud sites become underdeveloped. Side lighting, or lighting under the canopy, can remedy this.
Why Some People Grow Weed With Under Canopy Lights:
Even light distribution for dense crops: If you have particularly bushy plants, or many plants in a cramped grow tent, then light that is coming from above will usually only illuminate the top of the canopy, leaving the underside in darkness. With very dense crops, this can be a problem.
When lit only from above, the main, top cola may grow very large, but the lower down the plant you go, the smaller the buds will become. This can lead to “popcorn” buds, which, as the name suggests, are very small buds that are small and fluffy. Under-canopy lighting will ensure that lower buds still develop to a good size.
Efficiency:
Illuminating plants in their entirety will help them develop healthily and vigorously, leading to greater efficiency all round. If plants don’t get enough light, they can’t photosynthesize, regardless of how optimal all other conditions are. So adequate lighting is fundamental to a good grow.
What Is Side Lighting?
Most commonly, people use CFL or LED side lighting, which employs tubular bulbs or strips that hang down beside plants, evenly lighting them from the sides—not directly beneath. Alternatively, some growers use lighting that moves throughout the day, imitating the movement of the sun and ensuring that all parts of the crop get a good dose of direct light. For most indoor growers, though, this moving lighting is probably unnecessary.
Why Some People Use Side Lighting to Grow Weed:
Very large plants: If growing very large plants, then the lower colas may be so far from the canopy that even if light penetrates, it’s just not that strong. Using side lighting can help to get an even spread of light to tall plants.
Alongside CO2:
Some growers supplement grow spaces with additional CO2, which plants need for photosynthesis. As they are able to photosynthesize more efficiently with a constant supply of CO2, plants can make use of the extra light provided by side lights.
Bud Uniformity:
Side lights mean that buds will grow fairly evenly across an entire plant, rather than being disproportionately big at the top and popcorn-sized at the bottom.
Benefits of Growing Weed With Additional Lighting:
In certain situations, growing cannabis with additional lighting can be incredibly helpful. There are two general situations when it should be considered:
When a grow is very dense, and light from above can’t adequately penetrate the canopy. When all other factors are honed in, and side lighting can help to further optimize a grow setup.
Increased Yield:
Ultimately, most cannabis growers want big yields. And once growers have become very proficient in the fundamentals of growing, they tend to look for new ways to further increase yield. Well, side lighting and under-canopy lighting can do just this.
Better Light Distribution:
Obviously, additional lighting from under the canopy will distribute light more evenly across
your crop. Whether this is a meaningful benefit will depend on the two factors listed above. Optimal light distribution is always a good thing, but it’s down to you to decide whether it will make enough of a difference to employ.
Superior Plant Development:
Generally, plants that have adequate and even light exposure will grow into healthier specimens. While this ultimately means fatter buds, it comes with other knock-on benefits as well. Plants may become generally larger, with healthier coloration and more even development across the board. Plus, healthier plants are more resistant to pests and diseases, which is a great help.
Greater Bud Uniformity:
Instead of having huge buds at the top and popcorn buds at the bottom, why not have huge buds at the top and big buds at the bottom? Side lighting will increase bud uniformity, meaning larger yields and more attractive plants.
Adjusting Lights During Stages of Growth:
You might be tempted to blast your plants with side lights or under-canopy lights as soon as they come through the soil—but this is a mistake. Plants that are in the early vegetative stage contain light-seeking phytohormones, which cause the plant to grow towards light. In nature, this helps plants to find their way out of the undergrowth and up into the embrace of the sun.
So if you use side lights or under-canopy lights during the early or mid-veg stage, it will distort how the plant grows. Instead, you should only use them during the late vegetative stage and flowering stage, or even just the flowering stage.
Moreover, during earlier stages of growth, plants won’t be that big and their canopies won’t be too dense, so additional lighting should be unnecessary.
Side Lighting: A Handy Way to Boost Yields:
Side lighting and under-canopy lighting are both suited to advanced growers due to their relatively small benefit. Employed by unskilled growers, and they won’t make a difference. Wielded in the right hands, and some sources claim that yields can be increased by as much as 20%.
If you don’t think these additional lighting solutions are suitable for you just yet, then take inspiration from some of the other methods outlined in this article. Training methods are likely the main way that a grower can progress from beginner through to intermediate and advanced, pushing plant development to the max.