Cutting energy and water use while adhering to sustainable growing practices can keep you competitive and help your bottom line
By Omar Sacirbey
OutCo, a cannabis cultivation, manufacturing and retail business headquartered in San Diego County, California, marked a milestone May 7: The company harvested its final crop grown under high-pressure sodium lights. It took a couple of years to transition from the powerful but power-sucking HPS lights used by most commercial growers today to more expensive but more efficient LED lights. The switch was part of OutCo’s effort to be greener and more cost efficient.
“True sustainability efforts will be at the core of all businesses going forward, including cannabis,” said Allison Justice, OutCo’s director of cultivation. “These practices are not always easy but are critical to ensure the future availability of natural resources, lower our bottom line and remain competitive.”
In an age of plunging wholesale cannabis prices, sustainability is as much – or more – about cutting costs to survive as it is about recycling and reducing carbon footprints to be green.
“Everybody is dealing with such thin margins, so everyone is looking to be sustainable in terms of, ‘Will I be in business in five years?’” said Casey Rivero, cultivation manager at Yerba Buena in Hillsboro, Oregon.
While companies like OutCo and Yerba Buena are ahead of the curve, a growing number of cultivation operations are adopting sustainable growing technologies and techniques, experts said.
“My gut feeling is that the industry is generally getting more efficient on a production basis and facility basis,” said Derek Smith, executive director of the Resource Innovation Institute in Portland, Oregon, a nonprofit research organization that promotes energy and water conservation in the cannabis industry. The institute plans to release a report this summer exploring energy use in the marijuana industry and ways that businesses can reduce their energy costs.
“The industry is more efficient because people know that if you don’t figure out how to make your operation more efficient, you won’t be competitive,” Smith said.
To successfully transition to a sustainable cultivation model takes not only ambition but a new way of thinking. Growers generally measure the efficiency of their operations in terms of how many grams they can produce per square foot, but that must – and will – change, predicted Eli McLean, a cultivation consultant in Salem, Oregon. “That used to be the equation. But now we need to pay attention to how much did a pound cost to produce. That’s a huge side of things.”
In other words, being green is good for your bottom line.
Marijuana Business Magazine interviewed top commercial cultivators who employ sustainable cultivation methods. In the following pages you’ll read their insights into how to cut costs and be greener by way of electricity and power consumption, water use, earth and nutrient practices, and pest and contaminant management.
Moderation, homemade brews and guano are three ways to make the most of nutrients
Nutrients have bred many a false hope among marijuana growers. Soil amendments, of course, are important to growing healthy plants. But often they are overused in the belief that more nutrients mean bigger, better plants.
Quite the contrary. It’s possible to give your plants too much nutrient content. There is a point of diminishing return, after which any additional nutrients are wasting money while compounding the harm being done to local water sources.
“I see a lot of redundancies in fertilizer usage. People just load up on stuff because they think their plants need it,” said Christopher Vaos, a cultivation consultant in Colorado specializing in sustainable techniques.
Here are three tips for being more sustainable in your nutrient practices.
Don’t Overdo It
Moderation is a must.
“The most common mistake with nutrients is that people are overusing them,” Vaos said. In particular, growers overuse nitrogen, soluble phosphates and potassium. All are commonly used nutrients that can cause algae blooms and poison fish, he said.
Just as it’s helpful to look at plant tissue to understand how much water your plants need, plant tissue analysis can tell you what your plants are getting and lacking in the way of nutrients.
“By looking at tissue analysis data, we can see what a plant is metabolizing and using,” Vaos said. But tissue analysis requires gas chromatography, which can be expensive, Vaos cautioned.
Another way to gauge what nutrients – and how much – your plants are consuming is to run a sap analysis that looks at the composition of soluble ions in the juice of the plant, Vaos explained.
The difference between the two, he noted, is that a plant tissue analysis examines the nutrients that have built up over time, while a sap analysis tells you what nutrients are being consumed at that moment.
Whip Up Your Own Mix
Making your own nutrient mixes can lower your costs and environmental impact. But it requires some expertise and lots of experimentation.
San Diego County, California-based grower OutCo was using a commercial brand fertilizer in 2016, when Allison Justice joined the company with a Ph.D. in plant and environmental science. Justice, the company’s cultivation director, said the fertilizer did a great job, but it was pricey. She estimated OutCo spent $200,000 annually on one room of 500 plants while going through five crop cycles.
Justice didn’t dispute the results. She came from the vegetable-growing world, where a good profit margin is just 1.5%, and wanted to dwell less on bolstering the bottom line. She spent a year looking at nutrient mix formulations for poinsettias, tomatoes and other plants. She also combed through the scant amount of literature on cannabis and nutrients, explored the ingredients of the commercial brands and then developed her own formulation.
That brew is now being tested in a room of 500 plants that at press time were a week from being harvested. Their overall appearance was as good or better than plants grown on commercially available bottled solution.
The big difference: The homemade nutrient mix cost only about $8,000, or a fraction of the cost of the commercial product. “It’s exactly the same ingredients,” Justice said. “And they’re all sustainable.”
Like Vaos, she stressed the importance of not overfeeding.
Many of those solutions also load up on ingredients that can be harmful when used in excess, Justice said. For example, most plants need 50-70 parts per million of phosphorous, a major plant growth booster. But some commercial brands have as much as 250 parts per million of phosphorous.
“Phosphorous runoff in agriculture is a huge problem for aquatic life,” she said. “Giving the plant just what it needs, making sure it can take up most of what it’s fed, making sure there’s minimal runoff, that’s how we go about being sustainable in our approach.”
Growers who use soil have a wide variety of organic nutrient options to choose from. Some organic soil and nutrient sources are:
Kelp: Also known as seaweed, kelp is not a primary source of the three macronutrients: nitrogen, phosphorus and potassium. But it has more than 60 trace minerals, plus amino acids, enzymes and alginates. Kelp also contains mannitol, a natural sugar that breaks down micronutrients and makes them available to plant cells. Kelp improves soil health, seed germination, plant vigor and sugar content. And it stimulates more lateral root growth and larger root mass.
Guano: A combination of seabird and bat droppings, guano is loaded with beneficial bacteria and – depending on the type of bats – essential macronutrients. For example, Mexican bats have a bug diet, and their guano is high in nitrogen, while Jamaican bats eat fruits and therefore produce high-phosphorous excrement, which aids in the flowering stage.
Lobster and Crab Shells: Lobster and crab shells, typically harvested from seafood processors, are excellent sources of nitrogen, phosphorous and calcium that are best applied in the flower stages of the plant cycle. They also contain a carbohydrate called chitin that helps retain moisture and deter insects.
Worm Castings: The manure created by worms is packed with bacteria, fungi, protozoa and nematodes, which revitalize the soil’s food web, or community of organisms, which help keep soil rich. Worm castings also help break down organic matter such as decomposing food waste.
Super Soils: Super soils are augmented with nutrients, microbes and other materials that are beneficial to both marijuana and hemp plants. Some growers favor putting plants in super soils rather than adding nutrients to plants.
Three ways growers can lower their electricity bills without sacrificing crop yields
Electricity consumption is typically the second-biggest cost incurred by indoor cultivation facilities (and often greenhouses), behind labor. According to cultivation company data analyzed by the nonprofit Resource Innovation Institute, grow facilities on average expend about 275,000 kilowatt hours per square foot of canopy. Some grows spend much more, while outdoor grows spend little or nothing on electricity, according to Derek Smith, executive director of the Portland, Oregon-based research organization.
The high cost of electricity for indoor growing shouldn’t come as a shock, so to speak, given a grow facility’s need for lighting, air conditioning, dehumidifying and other demands.
“The more competitive the market gets, the more people are going to have to pay attention to resource management,” said Casey Rivero, head grower at Yerba Buena in Hillsboro, Oregon. “Power is one of your biggest costs, and being able to efficiently maximize your power is key.”
While reducing your cultivation site’s electric bill without making major sacrifices on yield and quality may sound like a tall order, there are ways to do it.
The two biggest consumers of electricity, according to a 2014 study performed by the Northwest Power and Conservation Council, are lighting, which accounts for about 38% of energy consumption, and dehumidification and ventilation, at 30%. Cooling takes up 21% of power demands, while the remaining 11% of power use can be attributed to heating, water management, CO2 injection and curing.
That said, the easiest place to seek energy savings is through lighting – in addition to heating, ventilation and air conditioning, or HVAC. Here are three ways to cut your electricity bill.
Determine How Much Juice You’re Consuming
To save on power, you first must know how much electricity you’re consuming and what it is being used for, such as lighting and HVAC.
The simplest way to measure how much you’re using is to calculate your kilowatts per day. Next, estimate how many hours per day your lighting and HVAC equipment are running – and at what power level – to understand how much juice is going to each. Growers should know that the amount of lighting and HVAC being used will depend where plants are in the growth cycle. Outside conditions play a role, too, because air conditioners and dehumidifiers must work harder on hot and/or humid days, respectively.
“It’s kind of a guestimate, but it’s better than nothing,” Rivero said.
To get more accurate data, Rivero suggests using power monitors that can be placed on breaker boxes to track electricity consumption based on a particular power source, such as a specific wall of air conditioning units or lighting panels. How many breaker boxes a cultivation facility has varies on the size and design of the facility as well as what kind of power service systems (single phase or three phase) and voltage power the site. Yerba Buena, for example, has individual subpanels for lighting in every room as well as a panel for each of the facility’s 10 HVAC units. There are also panels for less power-intensive equipment, like water pumps.
Basic power monitors cost between $600 and $1,000, while the most expensive models can hit $10,000, Rivero estimated.
A cultivation site doesn’t need to buy a power monitor for every breaker. But having several makes it easier to run comparisons, say between different grow rooms, different days or between lighting and HVAC units within a room.
In addition, energy-management companies can install data equipment to make it easier to track and manage power consumption.
Get the Lowdown on LEDs
While lighting uses the most electricity at indoor grow sites, most cultivators still use high-pressure sodium lights, typically 1,000 watts. Not only is the wattage a major energy drain, but HPS lights produce high heat, forcing air conditioners and dehumidifiers to work harder – adding to utility bills.
More efficient and environmentally friendly LED lights have been around for several years, but only a small number of growers have adopted them. Many growers acknowledge that LED lights are more efficient but argue that they don’t produce the yields that HPS lights do and, therefore, reject them.
For example, Massachusetts marijuana industry executives were up in arms in March after regulators imposed a cap on electricity use amounting to 36 watts per square foot of cultivation space. The move, in effect, forced growers to adopt LED lights – a move some executives hope to overturn.
When Allison Justice arrived at San Diego County, California-based OutCo in late 2016, she also was told that LED lights couldn’t perform like HPS lights, and that whatever the cost savings, they would be lost to the lower yields that were expected.
Justice, OutCo’s director of cultivation, wanted to see for herself, so last year she started running trials comparing 1,000-watt HPS lights with LED lights from Fluence, a commercial LED firm whose wattages were 330, 560, 660 and 1,000. More wattage equals more light intensity.
Testing on two strains, Justice and her colleagues found the LED 1,000-watt lights produced 21% higher yield than 1,000-watt HPS lights, while 660-watt LEDs resulted in 13% more yield and a 37% drop in energy use. That 37% decrease, Justice noted, didn’t account for savings from the air conditioners, which ran less because LEDs give off less heat.
Justice acknowledges that LEDs are more expensive – a Fluence 660 is about $1,280, while a standard HPS light is around $400 – but the cost is more than outweighed by the energy savings and increased yield.
Another advantage of LEDs: They allow growers to “double stack” a layer of plants on top of another one, effectively doubling the cultivation space. How? Because HPS lights are so hot, they must be farther from the plants than LED lights, which are cooler.
“It’s like getting another facility for free. The ROI on that is a no-brainer,” Justice said, referring to return on investment.
Following the successful tests, OutCo started retrofitting its facility for LED lights late last year, essentially interrupting production for six weeks to tear out old benches and lights and install new rolling benches, irrigation, drainage, HVAC and other equipment.
Since then, Justice and her team have harvested two crops each of several strains, including Mendo Breath, Cookie Pucker, Grape Pie, Strawberry Banana and Black Jack.
“Yield and quality is phenomenal,” Justice said. “There’s always tweaking to do when you start something like this. Overall we’re very happy.”
Other cultivators are also gaining confidence in LEDs.
“I was a holdout because I never saw the production that I could get out of an HID (high-intensity discharge) with an LED. They are now rapidly catching up,” said Eli McLean, a cultivation consultant and commercial grower in Salem, Oregon. “Once you run the numbers, you realize that you get good yield of top-shelf cannabis that cost me a third less to produce.”
McLean is now researching LED lights with quantum dot technology that he said operate at about 91-92 degrees Fahrenheit. The lights are manufactured by a company called QD Grow. “This means you’ll need far less latent cooling because you have far less latent heat,” McLean said. “I think you can see savings on your cooling costs of up to 65% for LED versus what’s being used today.”
Make Your HVAC Less Power Hungry
Finding ways to reduce HVAC power use is good for the environment – and your company’s finances.
Yerba Buena was able to get rid of its dehumidifiers, for example, which significantly reduced the company’s utility bills. How did the Oregon grower do it?
It adapted sensors that measure leaf moisture and air humidity and wired them to activate air conditioners (which also perform dehumidification) when the leaf surfaces reach a certain moisture level. Remember that leaf surfaces can transpire moisture because of heat from grow lights.
By activating air conditioners when leaves start to transpire – versus waiting for a preset interval – Rivero can both absorb air humidity and lower temperatures that had risen because of light heat. That, in turn, reduces leaf transpiration even more.
By reducing overall plant transpiration, and more efficiently timing air conditioning use, Yerba Buena was able to regulate and reduce humidity, so it could be handled by air conditioning alone. The company ditched its last dehumidifier in February.
“Our goal is to stabilize that humidity and heat. You need to pay attention to the leaf surface, because the leaf surface temperature is what’s going to allow that water to come out of the plant,” Rivero said. “The more sensing and control equipment you have that talks with HVAC and lighting together rather than separately, the easier it is to achieve that balance, as opposed to having those things separate and hope they line up.”
Five ways to keep critters and contaminants under control without resorting to dangerous pesticides
Using unhealthy pesticides is bad business. That fact is compounded by the multiple alternatives available to marijuana cultivators to control pests and contaminants like mold and mildew.
Here are five tips to keep pests and contaminants at bay.
Keep Your Plants Healthy
As Ben Franklin noted: An ounce of prevention is worth a pound of cure. Toward that end, growers say plant health is the biggest key to keeping pests and predators out of your grow.
“Plants have a strong immune system,” said Casey Rivero, head grower at Yerba Buena in Oregon. “The healthier the plant is, the more it’s getting its nutrients and will fight off problems.”
Christopher Vaos, a cultivation consultant in Colorado, agrees that prevention through maintaining healthy plants is the best strategy. But he cautions that applying excessive nutrients can induce the problems you’re trying to avoid.
“My view is that almost all plant disease – especially fungal disease – is related to not just environment but plant nutrition,” he said. When plants store too much nitrogen and potassium in their leaves but don’t have sufficient trace elements, they fail to efficiently metabolize nutrients like nitrogen and potassium.
“From a nutritive point of view, these plants love potassium, but too-high potassium in plant tissue is directly correlated to fungal disease, especially when it’s associated with low boron and low manganese,” Vaos added. “Few growers pay attention to that.”
Take Steps to Promote ‘Biosecurity’
Allison Justice, director of cultivation at California-based OutCo, said prevention “starts with really high biosecurity.”
- Growers change their shoes and clothes to minimize the risk of contaminants from the outside being brought in.
- After harvest, staff members should empty rooms of plants and clean all surfaces with a disinfectant approved by the Organic Materials Review Institute (OMRI) that combines parasitic acid and hydrogen peroxide.
- Staffers should also replace filters in HVAC equipment after harvest, because they can harbor fungal spores and even insects.
Rivero, for his part, dismisses precautions like Tyvek clean room garments and instead achieves biosecurity through beneficial bacteria and fungi. “If you have an abundance of beneficial bacteria, it’s harder for something from the outside to come in and destroy it,” Rivero said.
Know Your Plants’ Characteristics
Different plants have different resistances to pests and contamination, so it’s good to learn the strengths and weaknesses of the cultivars in your grow. For example, according to Rivero, the strain 9 Pound Hammer is especially susceptible to mildew, while root aphids prefer darker, waxier leaves, like those on OG and Cookie variety cultivars, as opposed to lighter green strains.
Strains that are more susceptible to problems should also be spaced farther apart from one another than sturdier strains, which reduces the risk of problems and makes them easier to spot if they occur.
Deploy Bug Assassins
Another pesticide-free way to combat pests are predatorial bugs and insects. But they aren’t all the same.
“You have to know what you’re fighting and how to fight it,” Rivero said.
For example, the best defense against spider mites are varieties of predatory mites such as Amblyseius andersoni mites and Phytoseiulus persimilis mites. There are also specific predators for soilborne pests like root aphids and fungus gnats, such as predatory nematodes and rove beetles of the genus Acidota.
You also must consider your nasty pests’ life cycles and when they might lay eggs. Just because you can’t see those spider mites anymore doesn’t mean they won’t return later in the cycle, when new eggs hatch.
Discard Problematic Plants
Another good solution is culling a plant that exhibits problems before it spreads trouble throughout your crop, said Oregon-based consultant Eli McLean.
Too few growers are willing to take that step, however, because they’re worried about losing a plant that could produce a crop worth a few thousand dollars. That strategy is penny-wise and pound-foolish, according to McLean.
“If people had crop insurance, that would also help. But they don’t,” he added.
From recycling runoff to capturing condensation – five ways to curb your grow’s appetite for H20
While water does not consume nearly as much of a cultivation facility’s budget as electricity, it is an area where growers can still save cash – and be mindful of Mother Earth.
Poor water management – for example, allowing nutrient-filled water to go down drains and into waterways – can do serious environmental damage.
Sustainable water practices essentially boil down to limiting water usage, managing runoff and recycling water.
Here are five ways to be smart about your water use:
Measure Your Water Consumption
As with electricity, the best place to start saving water is knowing how much you use. Flow meters are instruments that measure water use; some varieties also gauge certain water-quality measurements such as temperature, pH levels and electrical conductivity. (The latter tells you the level of contaminants in the water.)
Despite the availability of instruments that allow growers to know how much water their plants have and need, as well as drip-irrigation systems that enable growers to dial in how much water their plants receive, many growers still overwater, resulting in resources going down the drain.
The consequences of “drain to waste,” as the practice is known, include higher water bills and environmental damage to streams, ponds and other water sources that become contaminated by wastewater runoff.
“If you’re draining to waste, you’re spending way too much money and your company is going to go downhill,” said Casey Rivero, cultivation manager at Yerba Buena in Oregon.
Get to Know Your Plants
To avoid wasting water, Rivero starts with “a lot of tissue, soil and production analyses.” He and his team perform plant tissue analyses to know how much moisture different cultivars contain. They also track the health and look of the plants to know how much water each cultivar likes to drink.
For example, Rivero now knows that the company’s Do-Si-Dos indica strain takes 30%-35% less water than Pine-
apple Express or Silverhawk.
“Paying attention is key,” Rivero said. “Each cultivar has its own needs. We don’t feed all our cultivars the same exact amounts. We use drip systems in flowering rooms and can dial in specific gallons per minute on each type of plant. So, when we set up our rooms, we know which plants like to feed more, and which ones less.”
“We give our plants the exact amount of water they need and nothing else. There is no draining and wasting, there is no water runoff,” Rivero added. “That’s a part of cost control that a lot of people need to pay attention to. A few more gallons here, a few more milliliters of nutrients there – that adds up. Over a year, you’re at $15,000, $20,000.”
Choose a Drip System Carefully
If you do plan to get a drip irrigation system, growers note, make sure it can handle organic nutrient mixes. Synthetic mixes don’t clump, but organic ones do, meaning they can clog drip lines.
“There are more effective drip systems but never a plug and play,” Rivero said. “We’ve redesigned our drip systems and our watering systems four to five times now, based on how they’re working, and new concepts that we come up with to make our program more efficient.”
Recycle Your Runoff
Some growers do allow a small amount of runoff, which they then capture and reuse. Oregon-based cannabis cultivation consultant Eli McLean allows about 3%-5% runoff, which he captures and then sends through a filter he is developing.
“That water has lots of nutrients (and) pH balancers; that’s not good for waste treatment plants,” McLean said. “We trip out those nutrients and reclaim that water. That’s another water source you’ve stopped from going out of the building.”
Other businesses send captured runoff water through a desalination process that alternates cycles between water purification and water recovery. McLean said the process is nearly “100% efficient,” meaning it eliminates contaminants with almost no water waste.
One water-purification method McLean rejects is reverse osmosis, a process he said takes about 3 gallons of water to clean and reclaim 1 gallon. “That’s not efficient,” he said.
Another way to conserve water is through water condensate that comes from heating, venting and air-conditioning (HVAC).
McLean likes the gPod from Data Aire, a company that provides cooling solutions for the data center industry and recently moved into cannabis.
Here’s how it works: Heat that is usually sent to condensers and then vented into the atmosphere is instead rerouted through a dehumidification coil. The coil warms up and induces condensation from humid air that is also running over the coil.
McLean said a 10,000-square-foot room with 10 units working to cool and dehumidify can result in hundreds of gallons of water recovered from the air each day.
“It amounts to a sizable water savings,” McLean said. And, he noted, because that water is being retrieved from the air, it’s basically free of contaminants found in runoff or city water. Still, a company can run it through a filter in case any airborne contaminants like mold spores made it into the water.
“Many people used to put that condensate right down the drain, which is wasteful because it’s fresh water being wasted,” McLean said. “That is water you can use in your grow. There’s nothing in that water. It’s as clean as water can be.”