Should you grow your weed in soil, coco coir, or hydroponics?
The growing medium, or substrate, is where your cannabis plants develop their roots. The most common medium is soil, but you can also grow in other media such as coco coir, Rockwool, clay pebbles, or perlite, just to name a few.
With some growing methods, like hydroponic setups, the roots of your plants do not require a traditional substrate at all but are instead suspended directly in a nutrient solution.
The thing is, cannabis can grow well as long as the roots have access to water, oxygen, and the proper nutrients. There is no one-size-fits-all growing medium or cultivation method, as each has its advantages and drawbacks. Which one you choose will depend on various factors. To help you decide, let’s look at the differences between growing in soil, coco, and hydroponics.
GROWING CANNABIS IN SOIL
Growing in soil is the most forgiving method, and it’s also the most natural—just like Mother Nature intended. The roots of your plants draw in the nutrients they need from the soil, which is supplemented by the gardener with water and, depending on soil quality, extra nutrients.
What speaks for growing in soil is that it is easy and straightforward. Good soil is widely available, and all you need is a pot and some high-quality cannabis seeds and you’re good to go. Some cultivators will say that growing in soil—especially when done organically—produces the best-tasting weed. Then again, your yield may not turn out as big as with hydroponics or coco.
PROS AND CONS OF USING SOIL
Growing cannabis in soil is popular for a reason. Not only is it the most tried and tested method, but the easiest and most accessible as well. This is the substrate of choice among beginners, most organic growers, and guerrilla growers. Good-quality soil normally contains enough nutrients to sustain most or all of your plant’s vegetative stage, allowing you to save on nutrients and cut back on fertilisers. Moreover, the soil is more forgiving when it comes to pH, self-correcting as best as possible. Growers also tend to enjoy the flavour of soil-grown cannabis over any other.
On the other hand, soil-grown plants tend to move through the veg phase slower and deliver smaller yields by comparison. This also means plants will be slower to show signs of disease or deficiency, which you will need to look out for. Soil can easily accumulate mineral salts, requiring you to flush the substrate to prevent nutrient lockout and other issues.
Although finding the correct soil for cannabis is not impossible, if you choose soil that isn’t well-draining, your growth will be practically over before it has a chance to start.
GROWING CANNABIS USING COCO COIR
Growing cannabis in coco coir is sort of in-between growing in soil and growing hydroponically. It offers the advantages of both, yet it doesn’t require an elaborate setup (pumps, tank, etc.) as hydroponics does.
Like perlite, clay pebbles, or vermiculite, coco coir is what’s called an inert growing medium. This means it doesn’t contain nutrients on its own but is instead used for structural support. When growing in coco coir, you have to give nutrients to your plants from the start.
Oftentimes, growers don’t just use plain coco coir when growing weed but add a bit of perlite as well. Adding perlite makes the substrate airier and improves drainage. This benefits root development, and thus encourages the healthy growth of your cannabis.
PROS AND CONS OF USING COCO COIR
Coco offers the best of both worlds as a substrate. Plants will grow almost as fast as with hydroponics, with equally top-notch yields, yet with the ease of growing in soil. You have full control over nutrients and pH, and the fibrous husk material gives roots support. Coco is a renewable resource that is more eco-friendly than soil and is often amended with perlite or even soil to create an ideal mix for cannabis.
In terms of downsides, coco is much more susceptible to pH and nutrient issues due to over/underfeeding. It naturally has the tendency to leach magnesium and calcium, meaning you’ll have to amend your substrate with these nutrients to provide adequate amounts. In general, coco requires nutrient supplementation from the start, putting the onus on you to administer feed at the correct times, and in the correct amounts. Coconut husks are often soaked in salt water or treated with chemicals before the sale, requiring you to rinse the substrate before use. Finally, sourcing coco is easy online, but it can be difficult to find in some local stores.
GROWING CANNABIS USING HYDROPONICS
Growing cannabis in a hydroponic system involves using water as the main growing medium. The roots of your plant are suspended in a dark box or sit in an inert growing medium suitable for hydroponics. A water-based nutrient solution is then drip-fed to the roots, keeping the plant sustained. This can offer a lot of advantages—especially where control is concerned—but it also comes with its own set of drawbacks.
There are various hydroponic methods that differ according to the inert growing media used and the way nutrients are administered. In addition to systems where the roots are suspended directly in water, there are also setups where the plants sit in Rockwool, clay pebbles, or perlite as water and nutrients are fed to them.
Hydroponic setups can range from rather simple to elaborate. Often, they feature a tank for water and nutrients, pumps, drippers, and special hydroponic planting pots.
PROS AND CONS OF USING HYDROPONICS
Hydroponics is something we tend to associate with expert growers. These systems allow growers almost complete control over pH and nutrient levels. If set up successfully, a hydroponic growth can result in accelerated growth and big yields as there is no soil buffer to keep nutrients from reaching the roots. You also don’t need to worry about soil-based diseases or pests. Any potential issues can be observed and mitigated quickly, and plants can recover faster.
At the same time, if not dealt with quickly, pH and nutrition issues can really set you to grow back. Also, water-based diseases are still a threat to your crop. Furthermore, it’s harder to grow organically since you are responsible for administering all the supplemental nutrients yourself, which may adversely affect the taste as well. Finally, these systems are somewhat expensive and complex to run, making them unsuitable for first-timers.
OVERVIEW AND COMPARISON OF CANNABIS GROWING MEDIA
We hope the above guide has helped you better understand the differences between each growing medium, and why you might select one over the other. Just remember, no growing medium is “best”—it really comes down to personal preference, resources, and your goals as a grower.
CONSIDER A SOIL GROWTH IF:
you are not yet confident in your skills
you want to keep things organic
you want the flexibility of being less attentive to your plants
you feel that soil-grown weed tastes better
CONSIDER THE HYBRID OPTION OF COCO COIR IF:
you want the best of both worlds
you want full control over nutrients and the structural support offered by coco
you want to get your feet wet with hydro, but don’t want to risk it all
CONSIDER A HYDROPONIC SYSTEM IF:
you want absolute control
you are happy to dedicate the time and effort required
you are confident in your skills
you want larger, faster yields