Ecology of growing

Today we live in a consumer society. This means that when consumption outstretches demand we end up wasting materials and resources. A main resource, which many indoor gardeners take-for granted, is electricity (another is water but we’ll save that for another issue). Various charities and organisations in the UK like to remind people that energy efficiency is both beneficial to the environment, and a sustainable way of living within our means. In this article we shall consider the present ecological implications surrounding homegrowing in the UK.

People like to think that homegrowing cannabis is an ecological pastime. That they are somehow aiding the environment, and so on… This is an urban myth! Firstly, we must make a clear distinction between ‘outdoor’ and ‘indoor’ cultivation (they aren’t the same thing!) Outdoor, the ecological benefits of organic cannabis farming are visible for all to see. Cannabis plants, grow quickly, provide shelter for wildlife, consume large amounts of CO2 and throw out lots of Oxygen in return. Outdoor cannabis finds semblance within Nature. Indoors however, when a growing area is bought into an artificial environment, the parameters of what ecologists term “ecology” becomes somewhat stretched.

The mathematicians might want to snatch a calculator and/or a pen and paper at this point. An average indoor garden (if there is such a thing) uses anyplace between 200 and 1500 watts of electricity for a 12hour period during its bloom cycle. Anyplace between this figure in cycles of 18 or 24hour veg. As we start to add up the kilowatts of energy expended by indoor gardeners within the UK, we realise just how inefficient cannabis growing can become. Since levels of inefficiency are usually measured against an overall target, this means there is always room for improvement.

Finding the right balance between levels of ‘consumption’ and levels of ‘production’ is the key to efficiency (and ultimately gardening success). Anyone can keep throwing extra kilowatts of electricity into a grow room, in the hope that it might increase the overall yield, and in many cases it will, but at what cost? If/when the costs of a room exceed the crop-return, something might be wrong. Not only is it possible for a grower to waste energy, but they also loose out on some buds. Many indoor growers like to judge levels of efficiency against a ‘grams per watt’ figure that discounts all the other electrical inputs that make a crop possible (we’ll come onto this in a minute). A ‘grams per watt per month’ figure actually offers a far more realistic overview of the efficiency displayed by both light-source and grower. That is, how many weeks does it take to yield 1.2g per watt? We’d imagine that the differential between an 8week indica and a 15week sativa are immense when it comes to calculations like this. Perhaps we’ll leave the number counting to the accountants once again…

As amateur electricians, indoor growers must learn to harness every last drop of energy that is made available. And then distribute it into the places/spaces that need it most. Electricity has a fixed price per ‘kilowatt-hour’ in the UK between 8 - 14p (we keep hearing different figures different places). This cost may vary depending upon many things including; the time of day (economy 7) and the type of voltage an appliance supplies (220 - 250volts). This is where the ‘Sparkies’ get off on all that technical stuff (volts, watts, amps, hertz, and so on). Understanding the running wattage of a ballast-unit compared with the fireup wattage is complicated stuff! But the principles are easy enough to grasp. An electrical heater may use more energy than a light-source itself (at which point it’s wise to unplug the heater and add another lamp). On the flip side, an industrial-grade air-conditioning unit (the sort that are impossible to hire in July) often draws more energy cooling a room than the lights heating it! At this point it’s a case of shutting down at least 50% consumption (or production, depending upon which way you want to look at it). Either way, once consumption outweighs production, any ethos regarding ecology and/or self-sufficiency is lost. Now we can get onto all that other electrical stuff that helps an indoor room tick over. Starting at the wall, a timer uses about 5-10watts of electricity, an oscillating fan 100watts, a 125mm-extractor fan might use between 60-160watts (depending on setting). That’s 190 watts (on a cool day) before plugging in any lamps! Hydroponic growers may use extra electricity on top of this. Let’s say 20watts per water-pump, 100-300watts per tank heater and/or 100-150watts for each compressor unit if running aeroponics. That’s 500watts plus (on a warm day) for a single set-up. Lights range anywhere from between 125-1000watts per unit. At this point we shall take pause for thought. Ask yourself “Just exactly how many candle-watts of electricity is my grow-room using?”

While there are some really obvious ways of saving wattage (like replacing old bulbs that give out less lumens at the same cost as new ones), managing the resources available is far more ergonomic. For example, 2 x 600watt lamps use less electricity in relation to lumens than say 3 x 400watt lamps. Then again, although both set-ups use the same 1200watts of candlepower, the 400watt units may run at a lower temperature, and cover more surface area (depending upon the shades) than the 600’s. Ultimately reducing the overall temperature in a room saves additional output-wattage on climate control. This is why it is always important to allocate the right resources into the right area. A computer fan will not compete with a 600watt bulb, just as a 250mm-extractor unit would be over kill when using fluorescent tubes.

Re-circulating ‘old air’ is also a waste of energy (and bad horticultural practise). Plants don’t want to be breathing the air they’ve already used. The cost involved in reconditioning spent air is also very expensive. A carefully managed passive intake system, requiring little electrical input, and a good electrical output, is often all that is required to keep air flowing. Remember, outdoor temps are invariably always cooler than indoor temps in the UK so creating fresh airflow can be as simple as opening a window. Making even the most minor of alterations and changes to a garden will often have a major effect (be it positive or negative) on growth, this is after-all one of the principle rules of phenotypic variation in plants.

The future is bright, not orange (change those old bulbs!). Eco-bulbs, digital ballasts, solar panels, hydrostatic fuel blocks, (and even perhaps domestic nuclear fuel cells one-day), shall revolutionise the way that we think about energy consumption while growing crops indoors at home. It has already been proven that where/when people produce their own electricity, they consume less. The onus is on the individual to conserve energy, so that his/her levels of consumption supply their own production, with always a little extra to spare. It’s not always possible to place a wind-turbine on top of a grow-room, and we all know that double-glazing costs more than it saves, but this doesn’t mean that people can’t start making some little changes here and there when they grow. It’s logical, ecological and most importantly beneficial for gardeners to think about the energy that goes into growing their plants.

It’s always the case that the people making small changes today make big differences tomorrow. For this reason we’d like to retract the idea that urban cannabis growers don’t practise ecological methods of cultivation; it’s just that the parameters of “ecology” sometimes get overlooked when push-comes-to-shove. The cannabis community actually stands at the forefront of innovation when it comes to intensive methods of cultivation. One of the reasons for this is that ANYONE that grows intensively is possible of prompting change, by testing out new ideas, products, and innovations. In this way the future parameters of gardening are constantly being revolutionised by cannabis-growers themselves; as they strive to reduce in-put and maximise out-put, making harvest-time a gardening success.