Cannabis thrives when temperature, humidity, lighting and other conditions are ideal. The legalization movement makes matters even less stressful, but make sure to check with your local laws and regulations before building.
Soil, or any other growing medium for that matter, should be loose and porous. This allows fresh air to reach the roots. Even rich soil may need supplemental nutrients as it loses nutrients later in the grow. Cannabis requires nitrogen, phosphorous, and potassium, as well as several micronutrients like iron.
Vegetative stage requires higher ratios of nitrogen, whereas blooming or flowering stage requires more potassium and phosphorous. Another very important first step to any outdoor growing is security. Cameras are a must. In fact, some outdoor wireless video cameras alert you of intruders early. After all, nobody enjoys being ripped off from their hard work.
1. Location, Location
Along with privacy, the greenhouse location should receive full sunlight from sunrise to sunset. Also, consider the sun angle of each season, along with any structures or hills. For instance, south-facing slopes of hills or mountains receive far more light in the northern hemisphere, and therefore facilitate better growth than you would get on the northern slope.
Use a lightweight, inexpensive, but durable material for the greenhouse’s frame. Aluminum works well, as it doesn’t rust or otherwise corrode when exposed to moisture. The outside can be made from anything transparent or slightly translucent, such as plastic film, fine cloth mesh and more. Note that cloth mesh is unlikely to trap heat well during cooler seasons.
3. Temperature Control
Generally, cannabis plants thrive in temperatures from 68 to 77 degrees Fahrenheit. Bigger plants can thrive in temperatures up to 82. Depending on the climate, one may be able to grow without a heater or cooler, especially in the summer and fall.
4. Humidity Control
A dehumidifier will be need for humidity control. Seedlings and clones like humidity levels between 65 and 70, vegetative stage plants at 40 to 70 percent, and flowering plants at 30 to 40 percent humidity.
Cannabis plants, like any other plant, respires in a similar way to people, except the opposite happens: They take in carbon dioxide and make oxygen. Good ventilation will ensure an adequate supply of carbon dioxide for the growing plants.
These are the main focus points to work on when building a cannabis greenhouse. Excellent lighting conditions, along with the right temperature, humidity levels, ventilation and growing media, will ensure robust and massive growth, along with rewarding yields.