Coco chips and orchid bark are two popular growing media for plants. Both offer distinct advantages, and their differing characteristics suit various plant needs. This article compares these options to help gardeners make informed decisions.
Understanding Coco Chips
Coco chips are a byproduct of coconut husks. After harvesting, they are processed through retting, washing, buffering, and cutting into small, uniform pieces. These chunky chips offer good aeration to plant roots while retaining moderate moisture.
Understanding Orchid Bark
Orchid bark, primarily from fir or pine trees, is a widely used horticultural substrate. It is harvested, cleaned, and processed into various irregular shapes and sizes. This natural material creates an open, airy environment around plant roots, valued for its excellent drainage capabilities that prevent waterlogging.
Head-to-Head Comparison: Coco Chips vs. Orchid Bark
Water Retention and Drainage
Coco chips balance water retention, absorbing moisture within their porous structure for gradual release to plant roots. They hold significant water without saturation, providing consistent moisture. Orchid bark offers superior drainage due to its larger, irregular pieces, which create numerous air pockets. Water passes through orchid bark rapidly, preventing standing water around root systems.
Aeration
Coco chips’ chunky nature ensures good air circulation within the root zone, preventing compaction and promoting healthy root development. Their consistent particle size helps maintain aeration. Orchid bark excels in aeration, its structure creating abundant spaces for air exchange around roots. This high porosity benefits plants requiring substantial root oxygen.
pH Levels
Coco chips typically have a near-neutral pH (5.5-6.5), suitable for a wide variety of plants. Some products may have higher sodium levels, mitigated by proper washing and buffering. Orchid bark tends to be slightly acidic (4.5-5.5), advantageous for acid-loving plants.
Decomposition Rate and Longevity
Coco chips exhibit a slower decomposition rate, maintaining structural integrity for two to five years. Their lignin content contributes to this durability. Orchid bark generally decomposes more quickly, typically within one to three years. As it decomposes, it releases nutrients and can compact, reducing aeration.
Nutrient Retention
Coco chips have a relatively high cation exchange capacity (CEC), allowing them to hold and release nutrients to plant roots as needed. This prevents nutrient leaching and ensures efficient nutrient uptake. Orchid bark has a lower CEC, meaning it does not retain nutrients as effectively. Gardeners using orchid bark often need to fertilize more frequently.
Sustainability and Sourcing
Coco chips are a renewable resource, a byproduct of the coconut industry, making them a sustainable choice. Their production often utilizes waste materials. Orchid bark is also a renewable resource, derived from tree bark, often from sustainably managed forests. Both materials represent environmentally conscious choices.
Cost
Coco chips are generally more cost-effective, especially in compressed blocks that expand significantly upon hydration. Their widespread availability and efficient processing contribute to accessibility. Orchid bark, particularly high-quality, aged bark, can sometimes be more expensive due to sourcing and processing requirements. Price can vary based on bark type and preparation.
Choosing the Right Medium for Your Plants
For plants preferring consistent moisture without waterlogging, such as many aroids, monsteras, or philodendrons, a mix incorporating coco chips is highly beneficial.
Orchid bark is an excellent choice for epiphytic plants like orchids, hoyas, and some bromeliads that thrive with rapid drainage and significant air circulation around their roots. These plants are accustomed to growing on trees, where their roots are exposed to air and quickly dry out after rain. A blend of both coco chips and orchid bark, alongside other components like perlite or pumice, can create a custom medium that balances moisture retention, drainage, and aeration for a wider range of plants.