A Practical Look at Light DEP for Cannabis Cultivation

by | Sep 15, 2024

What is a light DEP system? When it comes to growing cannabis, it’s all about applying the lighting techniques mastered within the indoor grow room to the great outdoors.

It essentially means using simple technology to force outdoor crops into flower, well before the days grow shorter in the regular fall harvest season.

Light DEP for outdoor growers can double annual harvests, reduce the risk of inclement fall weather, and reap mid-season profits.

What is Light DEP?

In most regions with a climate suitable for outdoor cultivation, growers can only manage one harvest per year. But, by installing light DEP technology, it’s possible to double down to pump out two harvests in a single growing season.

Light deprivation, affectionately called light DEP by cannabis cultivators, is an outdoor cultivation technique that restricts the number of hours of light plants receives to trigger an early flower cycle.

This cultivation method requires simple technology, like a light-blocking tarp thrown over a hoop house. However, commercial operations may invest in more advanced mechanisms, like retractable blackout screens rolled over greenhouses.

How to Grow Light DEP Cannabis

If you are familiar with the light schedules used for indoor growing, light DEP uses these same techniques but outside. That means, instead of letting your plants naturally switch into flower with the shifts in season and daylight hours, you manually trigger it with light-blocking tarps.

During the vegetative stage, plants follow the sun’s schedule. Around summer solstice, this could mean 16 hours of daylight (depending on region).

Naturally, the shorter fall days tell cannabis plants it is time to focus on flowering. But, with the light DEP technique, growers tell plants when to switch by covering the plants with a light-proof tarp.

The light DEP schedule for flower is 12 hours of light and 12 hours of dark, which is the exact schedule that indoor growers follow.

What Is a Light DEP Greenhouse?

Many commercial growers grow in light DEP greenhouses. Like a traditional greenhouse, it’s a semi- to completely permanent outdoor facility that uses sunlight to grow but offers some environmental protections and climate controls.

The only difference is that light DEP greenhouses have a special, retractable blackout plant cover that envelops the greenhouse when growers want to restrict daylight hours.

There are even fully automated light deprivation greenhouses, but many growers rely on manual or power-assisted add-ons that pull the blackout greenhouse cover on and off as needed.

Yet, even home-growers can implement this technique without a commercial greenhouse. A light-blocking tarp thrown over simple hoop houses installed down each row works just as well, although it requires the grower to adhere to a strict schedule.

What is a Light DEP Strain?

Many factors influence strain decisions, including climate, market demands, availability, and cultivation techniques. Light DEP should also play into strain selection.

Light DEP

Ask your supplier or local breeder about the expected length of flowering and vegetative cycles. Strains with rapid and vigorous vegetative growth are ideally suited to light DEP, as it means larger plants in a shorter period. When you make the switch to flower, that translates into more bud.

Does Light DEP Increase Yields?

Technically speaking, light DEP yields per plant are lower than a more traditional outdoor cultivation approach. Because you are stopping the vegetative stage early, plants don’t get as large and don’t produce as many flowers as you’d expect from the usual sun-grown monsters.

However, if you take a step back and measure yields annually, there is a real possibility of increasing overall production.

Even if each harvest is slightly smaller, you’ll get two crops per year. This will ensure a greater annual total of light DEP yields than you’d get while growing under normal seasonal conditions.

What’s more, commercial growers usually stagger conventional outdoor crops with one or more greenhouses filled with light DEP plants. This means they have one set ready for harvest in summer and another ready in fall.

Top Three Manufacturers for Light DEP

The following companies provide a range of solutions for both small and large-scale cannabis operations, helping growers increase yields and control environmental variables.

Fullbloom Light Dep Greenhouses – Known for their fully automated systems, Fullbloom offers customizable solutions like the Gutter Connect Greenhouses and Titan Series, designed for commercial-scale growers. Their systems provide excellent environmental controls, and they use high-quality materials like Allied Certified US Steel to ensure durability in harsh conditions​.
Full Bloom Light Deprivation

Agrify – Agrify specializes in advanced technology for indoor and greenhouse cannabis cultivation. Their systems are renowned for their automation, which includes micro-environment control, vertical farming units, and data-driven insights to optimize cannabis yields and quality​. Marijuana Venture Green Vault Systems

Nexus Greenhouse Systems – Nexus provides highly durable light deprivation systems that integrate rack-and-pinion devices, automated motors, and fabric curtains for optimal light control. They cater to large-scale commercial growers seeking to maximize efficiency and production.​ Marijuana Venture

Final Considerations for Light DEP Cannabis Cultivation

If you choose to experiment with outdoor light DEP, there are a few final aspects that will require your attention: temperature and light leaks.

With the sun still high overhead, it can get quite hot within a blackout greenhouse. Therefore, ensure you monitor temperatures inside and use additional temperature controls to keep it within safe parameters.

You’ll also need to test for light leaks. As with indoor growing, light sneaking underneath during the dark period can confuse plants and frustrate harvests.

But with these two potential hazards under control, light DEP gives the outdoor farmer an added layer of control. More control means more predictable harvests and increased annual profits.