How To Avoid The Threat Of Cannabis Light Pollution

Outdoor planting season has finally arrived! This is the time of year when cannabis growers are looking for suitable spots in their gardens or on their balconies to take advantage of the warmer temperatures and bright sun for their plants. With cultivators getting hyped about finally being able to grow outdoors (and many likely having spent a small fortune on seeds, substrates, and fertilizers), one no-less important factor is often forgotten: light pollution. Light pollution can be a real danger to your crops by interrupting its all-important dark cycle.

THE IMPORTANCE OF PHOTOPERIOD

As photoperiod plants, cannabis relies on a light-dark cycle to decide when to make the switch from vegetative growth to flowering. Simply put, when the duration of daylight hours naturally decreases at the end of summer, your plants will sense the change in seasons and focus all their energy on making great, big buds. In the Northern Hemisphere, days progressively grow shorter after the summer solstice, with flowering initiating somewhere around August.

One issue with growing photoperiod cannabis strains is that the dark phase really cannot be interrupted. Unfortunately, light pollution from artificial lights, such as street lights, can be enough to really throw a wrench in your operation. Depending on the frequency and severity of the light pollution, the stress can cause plants to revert back to the veg phase, or to become intersex. This means they will start to produce pollen and grow seedy buds as a male plant would. Not ideal for the average home grower.

FINDING A GROW SPOT OUTDOORS WITH LITTLE LIGHT POLLUTION

When you’re scouting for a good spot to plant outdoors, always take light pollution into account. To be sure you’ve found a suitable location, you will of course have to wait until it gets dark to see if there’s anything that could possibly contribute to a disturbance in the dark cycle. Obvious culprits like our street light example are easy to spot, but others may not be so obvious.

If you're not sure whether it's really dark enough for your plants, there’s a trick you can use: once it’s dark, visit your location and take a magazine with you. Open it up and see if you can read some of the larger headers and descriptions. If you can still read without a problem, the spot may not be ideal. Of course, many growers only have so many options for places to grow. One thing that microgrowers can benefit from is planting in pots. Having the ability to move containers around as needed can be quite helpful in this scenario.

LIGHT POLLUTION AND GROWING IN A GREENHOUSE

A greenhouse is designed for your plants to take advantage of the “big bright light in the sky”. It combines the benefits of growing outdoors, with its abundance of natural sunlight, with the increased control of an indoor grow. However, light pollution can still be a problem for greenhouse grows, since you can’t simply flick a switch on and off to control the lights as you would indoors. Once again, you are at risk of light pollution from various sources. And because you can’t usually transport a greenhouse, you must find a way to work with what you have.

BLACKOUT SYSTEMS

One way to do this, depending on the size of your greenhouse, is to use blackout systems. This is somewhat of a catch-all for numerous techniques, but it generally involves using a mechanical system that moves a large sheet or some type of awning to block unwanted light. Just like your grow lights, your blackout system should preferably be connected to a timer. This way, you can give your plants an undisturbed 12 hours of night.

AUTOFLOWERING CANNABIS: IF YOU CAN’T ESCAPE LIGHT POLLUTION

Autoflowering cannabis strains, which flower based on age rather than on light-dark cycle, are ideal for those who simply cannot escape the reality of light pollution. Although autoflowering varieties have long been thought of as “inferior” cannabis, the innovative new strains available are impressive specimens that rival photoperiod cultivars. Of course, their biggest benefit is the fact that you don’t have to stay up all night wondering if your plants are being stressed by light pollution. Most autoflowering varieties will vegetate for around 4 weeks, after which they will begin to flower. That’s just what they do.