There are a number of pathogens that are blamed for root rot – Pythium and Phytophthora being two of the primary. Root rot happens when your roots are under stress & they are weakened allowing the pathogens to attack them – much like the human body. Often the stress is caused by over-watering, leading people to think there is too much water. The actual problem however is that when we over-water our plants, there is not enough air in the root zone. If the growing media has to many fine particles within it, the fine particles will fill up the spaces between the larger particles and thus root rot may occur.
To aid in ensuring you do not get root rot in the future, your grow media plays a huge role here. You may have heard the term Air Fill Porosity (AFP) or Water Holding Capacity (WHC) amongst growers. A good growing media should have an AFP somewhere between 28 – 35%. Anything close to 40% or above, will mean the water may not move sideways enough to utilize the whole pot volume for root growth or to flush it properly.
Many grow medias have lots of fine material. Some Coco brands have a lot of fine “coco pith dust” resulting in a much lower AFP & a much higher WHC. Growers often add Perlite, Hydroton (Clay Pebbles) & other amendments to open up their media to increase the Air Fill Porosity & decrease the Water Holding Capacity due to the fine material found in many Coco grow media products.
California Substrates Coco Coir is a little different. Not only do we buffer our Coco Coir with Calcium + Magnesium, unlike any other, we also sieve out the fine coco material, which is a lengthy expensive process. The result leaves the grower with a very light, spongy and pure Coco Coir with the perfect Air Fill Porosity and Water Holding Capacity. You can feed as much as you want without the fear of root rot or your plans holding too much water but they’ll be very forgiving. Next time you are in your local hydro store, ask the sales rep to open up the different Coco bags & by feeling the grow media, you will notice the difference.