When growing season comes around, coco coir is a highly recommended growing medium due to its neutral pH and superb aeration. However, as with any medium that will house the next vegetable, fruit, or flower garden, preparing substrates is a crucial step to a fungus and pathogen-free medium. Pasteurizing coco coir safeguards the substrate, freeing harmful microbes that can damage plants, reduce growth, or stifle a harvest.
What is Pasteurization?
Pasteurization is the process of heating a substance to a certain degree for an allotted time period in order to kill off pathogens, bacteria, and other harmful agents that could threaten the substance’s integrity. Pasteurization is a fairly straight-forward process and can be performed at home with a few simple items.
Pasteurizing Coco Coir
As with any substrate or growing medium, avoiding the introduction of harmful bacteria or fungus is beneficial for your plants. Although coco coir is already resistant to bacteria, pasteurizing it before use won’t harm it and will ensure a healthy growing season. Other mediums can be added to coir during the pasteurization process and, depending on the mix of substrates, the length of time it is exposed to heat can vary. Generally, adding 30-60 minutes to the overall time for mixed substrates is a good rule.
This method uses a five-gallon bucket with a lid and a thermometer. Coir is broken up, then inserted into the bucket. Spring or purified water is heated to 160-180 degrees Fahrenheit and poured over the coir. Then the bucket is capped with a lid to retain heat and allowed to sit for one to two hours. Some methods suggest filling a pillowcase with coir so that the substrate can be pulled from the bucket, squeezed out, and hung to dry.
Coir is added to a large glass jar and then set inside a larger pot of water. Water is heated to 160-180 degrees and maintained for an hour or more. The water bath should be monitored for consistent temperature and evaporation. This method eliminates the need to “drain” the coir and is more conducive for small batches.
Using a microwave to pasteurize is less desired than other methods. Oven temperatures can vary, so it may be challenging to keep the coir at a consistent temperature. Coir must be kept moistened before using the microwave method, and moisture loss must be considered.
Reusing Coco Coir
After growing season has ended, reusing a growing medium may be desired, and coco coir is up to the task. Be aware that existing root fragments will need to be thoroughly cleaned from the coir before reusing. It is recommended that coco coir pasteurization take place a second time before reusing coco coir as a growing medium.
Coco coir’s beauty lies in its simplicity and ease of use. With or without pasteurizing coco coir, it is an ample growing medium. Taking the time to prepare coir as a growing medium can result in abundant crops, tasty vegetables, and fruits, or a blooming bed of roses.