What is over the canopy of your plants matters more than you might think. There are several artificial lighting systems that market themselves as the closest spectrum to the sun. Plants, whether grown for food or medicine, will only contain what they are given through water, microbes, food, air and light. What is not grown under the full spectrum of the sun will be lacking at least one aspect of its medicinal or nutritional components.
Though the sun is the ideal source of lighting for plants, it also has some aspects that can affect a plant negatively. The invisible waves of ultraviolet radiation from the sun have two major components, UVA and UVB.
Among other things, UVA makes vitamin D absorption in our skin possible though it is also what causes our skin to burn from too much exposure. UVB is a shorter wave that can be more harmful to our skin and to plants. Causing cancer in humans, it has similar detrimental effects for plants.
Overexposure to UVB can impair the growth of a plant and result in lower yields, decreased immunity and more susceptibility to insects and disease. Human impact on the ozone layer has depleted the ozone’s ability to effectively filter UVB radiation and this is impacting plants, people, animals and marine life.
One way to use the beneficial aspects of the sun while avoiding the negative impacts of its harmful rays is to grow under greenhouse materials that filter out UVB, either partially or completely.
I have been approached many times by people wanting to spend a lot of money to improve their greenhouse environment. My advice is usually that the most effective and cost efficient thing you can do to upgrade your greenhouse is to make sure you have a high-quality fabric covering for your structure.
Greenhouse fabrics differ from greenhouse films in several ways. A fabric will have visible fabric strands, while a film will look more like a plastic bag or a plastic drop cloth. Fabrics are more durable and are typically tear and puncture resistant, allowing them to last years longer than films. Fabrics won’t yellow or deteriorate quickly, keeping them out of the landfill longer.
Look for fabrics that are light diffused. The diffused properties of a high-quality fabric allow the light to be more evenly spread throughout a greenhouse and penetrate deeper into the canopy and undergrowth. It will soften the sun while still providing everything the plant desires.
Anti-fog and condensation coatings are available on some products. A proper fabric will filter out UVB, allowing a plant to excel beyond the growth of full-sun plants that do not receive this filtration. Light diffusion and UVB filtration will increase terpene production, which translates into more material available for making concentrates and oils of your plants as well as giving them the shiny look of a plant grown under lights. These factors also assist in keeping soil temperatures down and lowering temperatures on the surface of the leaf of the plant, reducing your need for water and nutrients and allowing for higher ambient temperatures in the structure.
When growing for profit, your bottom line is greatly affected by the amount it takes to produce a market-ready product. Reducing your overhead is the easiest way to increase your profit margins. Growing in a greenhouse reduces your annual production expenditures by at least 50%. This increase in profitability is the main component that is going to allow greenhouse and full-sun-grown crops to dominate the market and greatly diminish the possibility of a profitable indoor garden.
Setting up an indoor garden properly costs quite a bit of money. A lot of people are leasing or renting buildings that they then have to build their growroom in, and when the lease is up all of these costs are lost and a good majority of the building materials are not reusable. Once you factor in the cost of all the lights and grow equipment, the operation winds up being in the same ballpark as it would cost to set up a greenhouse to grow the same amount of finished product in.
The huge difference between the two is that the indoor room is fully dependent on the usage of lights and fans and the cost of the electricity to run them. Electrical costs can run between 25 and 40% of your income in an indoor garden, while a greenhouse can almost eliminate this cost for half of the year and dramatically lower it for the remainder of the year.
Ridge and side vents allow for passive cooling while the sun provides a free source of light. No commercial product in the world is grown strictly indoors unless there are laws prohibiting them from growing in public.
I believe over the next few years we will see indoor cultivation become a methodology of growing strictly for hobby growers while more commercial gardens will be done under the sun.
Even though full-sun growing provides for the least expensive square footage to grow, it lacks certain securities and conveniences a greenhouse provides. Greenhouses will protect a crop from rain or snow and, as I mentioned earlier, diffuse and filter the properties of the sun that can be too intense for the plant.
Greenhouses will keep your plant and soil cooler and result in a more desirable finished product. Most importantly, a greenhouse offers you the ability to control your photoperiod, or light cycle, through light deprivation.
Just as an indoor grower controls their light cycle by turning their lights on and off, a greenhouse grower can control their light cycles by cutting out the light of the sun in the vegetative seasons of the year, for early flowering, and providing supplemental light in the seasons of the year that the sun does not provide the desired amount of light for keeping plants in their vegetative cycle.
Blackout tarps, preferably breathable, allow one to cut out the light of the sun in a greenhouse. Although this can be done manually, some greenhouse companies have mastered the ability to set up these systems automatically.
Consistent light cycles are important to avoid throwing off the natural growth patterns of your plant. Using the light deprivation technique, a grower gains the ability to control when they harvest, allowing them to meet higher market demand times of the year. When combined with supplemental lighting and heating, the farmer can create an environment for year-round production, providing fresh crops whenever desired.
When budgeting for a new project, I suggest you make your greenhouse one of the main priorities. This is not a place to cut corners. Every bit of structure that can increase the quality and quantity of your crops translates to larger profit margins.
A few bucks saved in the purchase of your greenhouse can translate to thousands lost down the line. Look for companies that specialize in light deprivation and ask how long they have been in that market. Ask them if they are growers or metal manufacturers unfamiliar with the needs of, and how to grow, your plant.
Make sure their structures have been tested and that they have a track record for success in the field you are in. It’s less expensive to do something right the first time than to fix something that reduced your initial investment in the beginning.
A high-quality greenhouse will not only give you peace of mind, it will allow you to create an ideal environment year-round. It will reduce the overhead that it takes to produce the crops you desire when you desire them. What this creates is the ability to focus fully on plant production and health, furthering a farmer's chance for success.