top of page
  • Cory

Clean Slate: Mastering the Art of Coconut Coir Preparation

Coconut coir bricks are hydrated and rinsed in a large bay concrete bay.
Bulk Coconut Coir Hydration Bay

Gardening enthusiasts, whether beginners or seasoned pros should always seek ways to enhance their knowledge and growing practices. This month, we delve into the benefits of washed and buffered coconut coir and how these substrates can transform your gardening experience.

The Science of Washed and Buffered Coir

Coconut coir which is derived from coconut husks, is an excellent soilless media known for its water retention, aeration, and sustainability. However, not all coconut coir is created equal in terms of chemistry and microbiology. The processes of washing and buffering coir are crucial in preparing the substrate for optimal plant growth. At Pioneers Harvest, we wash our coconut coir and then buffer as needed to meet our customer's needs. Every lot we make is tested in house for quality assurance and control purposes.

What is Washed Coir? Washed coir undergoes a thorough rinsing process with clean, filtered water to help remove excess salts and impurities which ensures a cleaner medium for your plants.

Benefits of Washed Coir:

  1. Lower Salt Content: Reduces the risk of rapid salt build-up in your plants over unwashed coir.

  2. Ideal for Organic Gardening: Provides a clean slate for organic nutrients and beneficial microbes.

  3. Enhanced Water Retention: A clean substrate will maintain moisture without becoming waterlogged.

What is Buffered Coir? Buffered coir is treated with a buffering solution to help exchange and rebalance ion levels to ensure better nutrient uptake and pH stability for plants.

Benefits of Buffered Coir:

  1. Optimized Nutrient Uptake: Ensures essential nutrients are readily available.

  2. Prevents Nutrient Lockout: Reduces the risk of nutrient deficiencies.

  3. Consistent pH Levels: Maintains a stable pH for healthy root development and vegetation.

Application and Use

When to Use Washed Coir:

  • Ideal for organic gardening and environments where organic amendments will be used.

  • Great for both indoor and outdoor use at any scale.

When to Use Buffered Coir:

  • Perfect for high-performance growing where nutrients are critically managed.

  • Great for both indoor and outdoor use at small or commercial scales.

A laboratory benchtop with two Saturated Media Extraction tests and three 1:1.5 slurry tests ready for analysis.
Lot samples are laid out for testing and analysis in our onsite laboratory.

Quality Control and Testing

At Pioneers Harvest, we make quality control and testing a priority. After hydration and buffering, our coir undergoes rigorous testing in our on-site lab to ensure consistency and quality. We currently analyze the following properties on-site:

  1. Temperature, pH, EC, and TDS: Using a 1:1.5 slurry test and benchtop multi-meters we track these parameters to ensure optimal conditions for plant growth.

  2. Ionization Levels: Through a Saturated Media Extraction test we measure the levels of calcium, potassium, sodium and nitrates with Ion-Selective Electrodes.

  3. Volumetric Water Content Percentage Test: By passing a low voltage current through a known volume of our media we can ensure that it retains the right amount of moisture.

  4. Microscope Analysis: Used to check for coir fiber damage and overall ingredient quality.

  5. 21-Day Seed Germination and Mold Test: Onsite lot testing of the media confirms that it is ready to use and free of seeds, mold and pests.

  6. Quarterly Third Party Testing: In house testing is important but we have to use other laboratories to confirm our testing every quarter with select blends/soil samples.

By engaging in soil science, chemistry, microbiology and horticulture, we ensure our soilless media provides the best possible environment for your plants!

Microbiology Benefits: Enhancing Growth Through Science

The way that we prepare our soilless media also offers unique advantage when combined with beneficial microbes, particularly mycorrhizal fungi. These fungi form symbiotic relationships with plant roots, enhancing water and nutrient uptake. Introducing specific mycorrhizae can drastically improve plant health by increasing the efficiency of nutrient absorption, particularly with phosphorus. Furthermore, predatory nematodes and beneficial bacteria can be added to control pests and promote plant health.

Soil Science and Microbial Benefits:

  • Mycorrhizal Fungi: These beneficial fungi extend their hyphal network into the media, enhancing water and nutrient uptake.

  • Beneficial Bacteria: They help fix nitrogen, promote plant growth hormones, and outcompete harmful pathogens.

  • Predatory Nematodes: These microscopic predators control pests like fungus gnats, root aphids, thrips, reducing the need for chemical interventions.

  • Enhanced Nutrient Cycling: The combined action of these microbes ensures efficient nutrient cycling, making nutrients more available to plants.

Horticultural Benefits:

  • Improved Root Health: The symbiotic relationships between plant roots and microbes enhance root health and development.

  • Disease Suppression: Beneficial microbes are selected for their ability to outcompete harmful pathogens, reducing the incidence of diseases.

  • Sustainable Growth: Using microbial inoculants promotes sustainable and environmentally friendly gardening practices.

Whether it's washed or buffered coconut coir; by creating a robust ecosystem within the soilless media, we support vigorous plant growth, enhance nutrient uptake and ensure the overall health of your plants!

A hydrated 1 gallon grow bag ready for transplant.
1 Gallon Grow Bag


Understanding the key differences and benefits of washed and buffered coir can significantly enhance your gardening growing practices. Whether you choose washed for its organic purity or buffered for its stability and nutrient optimization, both provide a robust foundation for healthy plant growth!


bottom of page