• Matthew Sheahan

PAR Maps and Uniformity

Being able to perfect the lighting system in your grow operation is something that takes a lot of time, practice, and experimentation. The perfect lighting setup requires far more than just a few LEDs across your subcanopy— if you’re looking to have a successful yield, that is. To truly master your cannabis cultivation, understanding the PAR maps and uniformity are critical.


If you don’t know what PAR maps are or what uniformity has to do with anything, don’t worry! That’s why we’re here. Today, we’re talking all about PAR maps, their use, and how uniformity plays a considerable role. By the end, you’ll understand why these lighting maps are so helpful to growers like you and me.



What Are PAR Maps?


First thing’s first: what even are PAR maps?


PAR stands for photosynthetically active radiation, and PAR maps are used to measure how much light a particular area of space is receiving. These maps measure the overhead value of a lighting system, demonstrating in a grid structure the amount of light each grid is actually absorbing.


By illustrating light measurement in this way, growers can easily see which areas of their grow spaces are receiving less light. On the same note, you’re able to see more concentrated regions of photons, too, particularly the grids directly underneath the light source.


With these PAR maps, growers can use them to simulate their own growing space. By placing light sources at the same position as their supplemental lighting, the PAR maps demonstrate directly how much PAR your canopy is going to get. This gives you incredible insight into your setup’s logistics and where (if any) adjustments need to be made.


One of PAR’s most significant roles is to drive a plant to photosynthesis. This is a process that’s crucial for cannabis plants to grow healthy and strong, resulting in a successful yield. However, too much lighting and too much PAR on a plant can create adverse effects if you’re not familiar with plant cultivation. That’s precisely where uniformity comes into play.


The Importance of Uniformity in Cannabis Cultivation


PAR maps are one of the easiest ways to see if your light setup reflects uniformity or not. If your lighting operation is uniform, then every plant will receive the same amount of photons from the lights up above. Having this sort of uniformity ensures that every cannabis plant grows the same, as none are getting more or fewer nutrients than others.


Unfortunately, achieving uniformity from glow lights isn’t always an easy task. The lack of uniformity can be due to a myriad of things, from the shape of your grow facility to the wattage of your supplemental lighting. Thankfully, PAR maps illustrate these inequalities effortlessly, allowing you to fix and adjust your chosen lighting as needed.


As we mentioned above, PAR maps demonstrate the PAR of your lighting using a grid-like approach. Essentially, the maps calculate the surface area’s exposure to photons in equal measurements across the lit region. So, if you have one light warming four plants, the PAR map would likely show that these plants’ inner four corners are getting much higher PAR readings than the outer four corners.


When a farmer can see the lack of uniformity, they can make adjustments to ensure that these light sources are equally distributing the right amount of light per surface area. The cannabis plants that the grower planted together are much more likely to grow at similar rates and with the same proper nourishment levels.


Simply put, uniformity under adequate lighting is one of the best ways to ensure consistent cannabis cultivation. There’s no reason why some of your plants should be subjected to more light than others! Instead, you can turn to study your grow operation’s tentative PAR map to see if all of your plants are getting equal attention.


Finding the Best Grow Light Positions


When perfecting your grow operation’s cannabis lighting system, you’re going to have to do some experimenting in terms of grow light positioning. The position of your grow light is what determines your cultivation’s PAR levels, so you need to be sure that you’re placing lights in spots that need them.


The distance of your grow lights on the subcanopy above your plants will play a huge role in uniformity and PAR levels. Some growers make the mistake of placing their lights just a few feet above their plants, effectively over-heating some and leaving others without proper nourishment. On the flip side, putting your lights too far from your plants can leave them reaching for more, growing sporadically, and not as healthy as they should.


Every grow operation is built differently, so take the time to proactively measure the PAR maps in your space with varying positioning lights. Eventually, you will discover the perfect position, height, and amount of lighting to cultivate the excellent cannabis yield.


Cultivating the Perfect Cannabis Plant


While this might take a little bit of time and experimentation, understanding PAR maps and uniformity as they relate to cannabis is essential. Comprehending these ideas and relationships gives you an inside look into the world of cannabis that most people don’t have, helping you to grow some of the best cannabis plants you’ve seen yet. We promise, taking the time to master these will be more than beneficial in the long run for your cannabis cultivation.


Here at Luna Cultivation, we’re focused entirely on helping growers like you perfect your hemp or marijuana yield. We specialize in lighting systems and their effects on this particular green plant, giving you all the tips and tricks we’ve learned thus far. Together, cultivating your dream cannabis harvest has never been easier.