Maximum Yield Cannabis Canada March/April 2023 | Page 30

tips from OUR BUDS

NAVIGATING

THE BIG WORLD OF

GROW MEDIA

The options for different types of available grow media out there can be dizzying . There are hundreds of products on the market with all manner of claims about their relative superiority to grow enviable plants . Which one to choose ?
by Chris Bond

All grow media is designed to support healthy plant growth , but how they do it , what they are made of , and how they can affect the plants they are supporting , and nourishing runs the gamut . No matter the type , growing media needs to provide the home , storage , stability , and the basics for the health and benefits to the plants that call their growing media home . Grow media should provide plants with both water retention and good drainage . It should provide the aeration needed for your plants ’ root systems to grow unimpeded and get the air they need to thrive . Ideally , it will also be long lasting and not change its composition much over time . Finally , it should be able to hold nutrients that are introduced so plants can use them as needed . Ultimately , the selection of grow media type will depend on many factors . The type of plants to be grown and their needs , the pH of the irrigation water , the type of system it is going in , preferences , and the budget of the individual grower will all play a role in media selection . Let ’ s look at some the pros and cons of the more common media types :

Peat Moss
Peat moss is a moderately priced , acidic medium with a relatively short useful lifespan . Peat moss is comprised of partially decomposed plants . There are three commonly available types . You can find sphagnum ( the most common ), hypnum , and reed or sedge peat mosses .
➤ PROS : Peat moss has a very high capacity to hold moisture ; up to 10 times its own weight . Conversely , it does not hold on to excess water . It drains well too . It is a great medium to use for acid-loving plants such as blueberries and plants in the rhododendron family .
➤ CONS : Its high acidity needs to be countered for plants that do not like a highly acidic environment , so products such as lime often need to be added when it is used . Peat moss can host several soil-borne pathogens , so it needs to be carefully monitored . It is also not environmentally sustainable . The supply of currently available peat moss is finite . Yes , more will be made in time , but it takes centuries to form .
Coco Coir
Coco coir ( or just coir ) is a medium made from the shredded husks of the coconut . It is a relatively inexpensive medium that has a neutral pH . Like peat moss , it does not have an exceedingly long useful life once put into use . It is sold under a variety of trade names and is available loose , in sheets , or in pre-formed bricks or briquettes . Coir will expand by up to six times its original size when fully saturated .
➤ PROS : Like peat moss , coir holds moisture well , yet allows for good drainage of excess water and good root aeration . It is a good medium for rooting and cloning , with claims that the coir dust actually promotes root development in addition to supporting it . Coir is biodegradable , organic , and a fully renewable resource .
➤ CONS : Coir needs to be treated prior to use . It is usually high in salt and chlorine , so coir must be washed and often treated with additional calcium and magnesium . The dust of coir can be a skin and lung irritant to some , and a mask and gloves should be worn when handling dry coir for the first time .
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