Cannabis can grow and flourish in a variety of environments, both indoors and outdoors. From a cultivation perspective, it’s a forgiving plant that will reward its grower if key essential needs are met. One of these needs is light—whether natural or artificial lights.
Simply stated, cannabis cannot survive when not allowed to engage in photosynthesis, and exposure to light is part of that process. Photosynthesis allows the plant to absorb the energy of lights from the chlorophyll in its leaves and convert it into energy. Carbon dioxide (CO2) and water (H2O) nurture the plant and allow it to create sugar for energy. This is a reality of growing cannabis. Both light and darkness at critical stages of its life cycle are necessary for it to thrive. While plants can grow with continuous light during the vegetative stage, a significant period of darkness will cause it to create buds and reach sexual maturity during the flowering stage.
Because light is absolutely necessary for cannabis plants to grow, most home growers invest in expensive lighting systems to simulate the light spectrum of natural light. This usually is accomplished through utilizing high-pressure sodium (HPS), metal halide (MH), or light-emitting diode (LED) lights. These artificial light sources allow cannabis growers to easily cultivate high-quality cannabis indoors. But can cannabis be grown indoors without artificial light? Absolutely! But the indoor grower faces some challenges to harness the free solar energy emitted from the sun.
When growing outdoors is not an option, greenhouses are one of the most obvious methods of growing indoors, and there’s much to be said for these stand-alone structures. In many ways, they capture the best of indoor and outdoor cultivation. The plants grown within receive natural sunlight while remaining in a controlled environment that protects them from harsh environmental factors like wind, rain, and hail, as well as the detrimental impact of insects and other pests—not to mention theft from unscrupulous human thieves. Greenhouses also allow control of environmental factors like humidity. They rank as the most turn-key method of growing cannabis indoors without artificial lighting.
If space limitations make owning a greenhouse impossible, there are other options available to those who want to grow cannabis indoors without lights. Like greenhouses, these alternative methods must harness natural light from the sun.
Conservatory, Solariums and Sunrooms
Besides greenhouses, the most obvious cultivation option available to home cannabis growers is a “sunroom,” which are popular retreats for many homeowners. A variety of household plants thrive in sun rooms across the country, so there’s no reason cannabis can’t flourish in the same environment.
If not built into the structure of an existing home, some people opt to screen-in a large porch area. The trick to a good sunroom for plants is providing a way to receive as much unobstructed light as possible. Screened-in sunrooms provide an excellent means of allowing sunlight to reach plants, but this material provides less protection from outdoor environmental factors like low temperature. Sunrooms in the United States should face southeast or southwest (followed by south) to receive the most sunlight possible. Cannabis should receive 5 hours of direct sunlight at the peak of the growing season in mid to late summer—although access to 8 hours or more is ideal. Within the sunroom, furniture or room decorations should not obstruct light from reaching the plants. The more access your plants have to direct sunlight, the better.
Although you hear the terms sunroom, and solarium used interchangeably, there are subtle differences, but both are intended to meet the same end: providing an enclosed area rich in natural light. A solarium typically has a glass roof and glass sides, maximizing light exposure and typically creating a warmer environment thanks to the sun’s rays. A conservatory, solarium, atrium, and sunroom are all very closely related and make a good indoor environment for growing cannabis without using lights. A sunroom is the most likely of the four to not have a glass roof.
A courtyard makes an effective growing area with protection from four sides. The main difference between a courtyard and an atrium is that a courtyard has no roof to shield the grow from environmental factors like rain and wind. Because they are generally built within the confines of a home’s walls, courtyards provide advantages over greenhouses and sunrooms for being more discreet—something that’s always good when growing cannabis.
Because of the four solid walls in courtyards, you want to avoid the shade factor as much as possible. Cannabis enjoys direct sunlight, so situating the plants near the center of the courtyard will provide the best orientation for receiving maximum sun exposure.
Patios with Translucent Roofs
Patios with translucent roofs are another ideal location for growing cannabis without lights. These areas usually have concrete or brick floors, which are great surfaces for regular water, cleanup and general maintenance of cannabis plants. Having a roof over the plants provides them limited protection from the elements, but definitely shields them from two big dangers: heavy rainstorms and hail damage.
In many ways, covered patios are another take on the sunroom and conservatory concept, providing a scaled down alternative to these more advanced and expensive structures. While they are less elaborate, they can be just as functional for growing cannabis. A translucent roof allows for light penetration from above, as well as limited sunlight exposure from the front and sides of the patio.
Bay Windows and Window Sills
In a south-facing room, large bay windows allow enough room to grow cannabis if sunlight can enter the room for several daylight hours. In rooms with bay windows or sliding glass doors, plants will do best when placed close to the glass. You don’t want them too far from the windows.
Window sills, although close to glass and fine for seedlings or young clones, do not have the space necessary for robust plant growth. Certainly, starting plants in these areas is possible, but before they reach more than a foot of vertical height they will require a more permanent location to mature.
Most cannabis plants grown with only the sunlight from vertical windows to aid their photosynthesis needs will grow with less vigor. The plants will usually be sparser, with comparatively spindly vertical growth and smaller leaves than plants allowed more direct access to sunlight. As well as les then optimum plant structure, the flowers will be looser and smaller, lacking the dense, large size most growers want.
Attics and Skylights
Because of their overhead installation, skylights are a great way to supplement or provide indoor lighting that’s good for plants. Of course, the number of skylights and their size will both be factors in the overall benefits these lights.
Attics equipped with multiple large skylights can be great locations for growing cannabis indoors without lights. Once again, the amount of light the plants receive will determine the overall success of the grow. Attics are removed from household traffic and pets, so their location is perfect for discreet cannabis cultivation projects.
While growing high-quality marijuana without lights indoors presents its share of unique challenges, it provides a realistic alternative to investing in expensive grow lights and paying lofty electric bills. If you want to try your hand at growing indoors with natural light, weigh your options and consider the locations and practices described here. Most likely your home and its design will present a way to harness solar energy from Mother Nature to fuel your grow.