The basis of every cannabis grow is the medium, both figuratively and literally. This is a crucial decision that every grower faces sooner or later. Many articles and texts have been dedicated to the differences between various types of substrates - and every time, it feels as if the same points are repeated over and over. The most classic comparison is between coco and stone wool substrates, of course. These two industries have been competing to win the hearts of growers, so it makes sense that rivers of ink have been used to highlight their main differences. While there are obviously pros and cons to both, at the end of the day, growers simply want to produce a premium product using a substrate that allows their strains to express their full genetic potential. And to grow a premium product, one needs a premium substrate - 2+2=4, after all. "We have a premium product in that there's extra care in the way we produce it," says Chris Vaos from HortGrow, a manufacturer of coco products.
What defines a premium substrate?
A premium substrate doesn't just refer to the inherent quality of the medium but also to everything related to handling and using it. "Stone wool is a silicate product," Chris says. "You shouldn't handle it with bare hands; you may need respirators and gloves." In other words, it's better not to scratch your eyes after touching it - not that you should do that in general. "Worker safety should always be paramount, especially in horticulture. Being natural and organic, coco coir doesn't pose the same risks as its stone wool counterpart," Chris points out.
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Speaking of natural materials, sustainability is currently a particularly important topic, with many growers and horticultural businesses striving for non-polluting cultivation. "Coco coir is derived from coconuts, which grow year-round, making it a renewable resource," Chris remarks. This is in stark contrast to stone wool, which comes from mined sources. However, perhaps the most significant sustainability issue concerns the use and disposal of stone wool versus coco coir - especially for North American growers. "There's no facility in North America to dispose of stone wool," he says. "If you consider that those plugs need to be replaced after every cycle, it goes without saying that you'd end up with piles of stone wool and would need to pay a substantial amount of money to get rid of it."
Running a business: main priority
Coco coir is widely used by berry and cannabis growers for being more pH stable and more resilient to both drought and overwatering. "It's like soil, after all. On the other hand, if a grower is using stone wool and it gets too dry, the roots may be destroyed," he points out. Berry growers especially appreciate coco's more pH-neutral properties, as it sits between stone wool, which is highly alkaline, and peat, which is acidic. "It's a middle-of-the-road medium for someone operating a precision CEA infrastructure."
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Chris explains that HortGrow products have proprietary characteristics that make them very well-aerated and provide proper water-holding capacity, making them a particularly suitable choice for both berry and cannabis growers. "Water-holding capacity is a big topic right now," Chris says. "It simply allows for better crop steering. Some of our growers have conducted side-by-side tests, including with other coco coir brands, and they've been able to shave off 2-3 days of veg time in cannabis." In other words, growers can get to the crop steering phase 2-3 days earlier. "On top of that, all growth stages can be completed in the same bag, from propagation to flowering. This reduces labor costs. By streamlining operations, growers can save both labor and space by going directly to the final container."
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Obviously, there are many aspects to consider when choosing a growing medium. However, it ultimately comes down to selecting the substrate that a grower feels most comfortable using - one that provides enough flexibility for them to work their magic. "The main priority is always to run a business, and if there's something that makes it easier, then it's a no-brainer."
For more information:
HortGrow Solutions
www.hortgrow.com