What is Light Deprivation?

Today’s post was contributed by Jonathan Valdman of Forever Flowering Greenhouses, an Indica Sponsor of the 1st annual Golden Tarp Award. 

Light deprivation, aka light dep, is the process of forcing plants to flower with sunlight in a time of year that is not normally the flowering period of the sun’s natural lighting cycle.

Similar to controlling the light cycle with a grow light by turning it on and off with a timer, farmers can control the budding cycle by blocking the sunlight, making the plants think it’s time to flower.

A 12/12 lighting cycle is typical and a number of methods that “black out” the growing area control that cycle. This can be done manually or automatically. Manual methods are more tedious, as the plants must be covered/uncovered at the same time for the entire flowering cycle with blackout tarps. High quality, breathable tarps can last for many seasons and prevent your local landfill from filling up.

Why Ventilation Still Matters for Light Dep

Keeping proper ventilation inside the blacked out area is crucial to avoid build-up of excess heat and humidity, which causes buds to stretch and mold. Much like an indoor room, exhaust and intake vents are excellent for light dep ventilation. Products such as the Breathable Wall allow for full air flow and no light leaks.

The area must be kept at zero lumens of light when the tarps are pulled so plants can continue to properly develop.

Environmental and Financial Benefits of Growing Light Dep Cannabis

The benefits of utilizing light dep techniques are huge. Just like growing indoors, the farmer has control of when they harvest. This allows them to bring their flowers to market in a time of year that they are worth more and will sell quicker.

Light dep drastically reduces, or completely eliminates, the need for high-powered grow lights, allowing farmers to keep more of the profits, reduce their carbon footprint and cutout the “silent partner” known as the local utility company or diesel supplier. When grown under high quality, light-diffusing greenhouse fabrics, buds have a similar frosty look to those grown under lights. This is another element that makes for a quicker sale and increases it’s per-pound price when compared to “full sun” plants.

How Light Dep Compares to Indoor and Outdoor

Light dep is quickly becoming the standard for cultivation. Compared to growing indoors, it has a much smaller environmental impact and drastically reduces the monthly overhead. Compared to growing outdoors, it affords the grower more control over changing weather patterns, provides privacy and allows for fresh product when plants under full sun are still in their vegetative stage or in early flowering.

Greenhouses are most commonly used to light dep plants, though many approaches have been successfully used. When used in conjunction with supplemental heat and lighting, a greenhouse with a light dep system allows a farmer to be forever flowering with minimal inputs year round.

As published in the North Coast Journal special section Aug. 7, 2014.