Fiji style potting mix

Seed Starting Potting Mix Recipe

The perfect seed starting mix mustn’t be too high in nutrients, which could harm delicate seedlings. The mix should also hold onto moisture without becoming soggy. Overly wet conditions can rot seeds and encourage fungal diseases such as damping off.

Our seed starting mix uses a soil-less recipe, so it’s beautifully light and fluffy and will promote good, strong growth and happy seedlings.


As a growing medium, coir chiefly serves as an alternative to rockwool, clay balls or peat moss in soil-less media. Typically, growers use coco coir, mixed with perlite at a half-and-half ratio, in hydroponic gardening. In this situation, emitters or pumps circulate water through individual planting sites, which generally require less growing media – usually peat moss in the United States – than plants grown in soil. Mixes containing coir, perlite and worm castings, or coir and compost also serve as alternatives to potting soil.


Coconut coir lends itself to hydroponic growing in particular, as it features a high cation exchange capacity, a measurement of media-to-root nutritional transfer. Fibrous coir does not compact easily, which leaves space for healthy root systems and promotes a strong aerobic rhizosphere for nutrient and water uptake. According to “Rosebud” Magazine, even fully saturated coir retains 20 percent of its air capacity. The same source reports that the medium’s natural hormones promote root growth and root protection. Coir’s high lignin content makes the medium well-suited for reuse, as it accommodates micro-organisms that inhibit decay. In terms of eco-friendliness, coir is an organic and completely renewable resource.


A controlled study conducted in 2002 reports that growing media composed of more than 50 percent coir caused reduced growth compared to purely peat media. Additionally, a Utah State University study concludes that “no brand [of coir] [performs] better than sphagnum peat.” This medium responds best to nutrient solutions; an excess of plain water may cause the coir to become chemically imbalanced. Although coconut coir is reusable, it still requires the addition of about 10 to 20 percent fresh perlite when reused for the third or fourth time.


Coir has a natural pH of about 6; liming materials increase the pH above ideal levels for most plants. “Buffered” coco coir, the type sold in most garden centers, serves best as a growing medium, as the chemical buffering process helps balance the substance’s calcium and magnesium content. Similarly, the addition of gypsum helps the medium overcome its low calcium and sulfur content.

Begin with two parts compost as your base. All parts are measured by volume, so it doesn’t matter what you use to measure your ingredients, so long as you’re consistent. The compost slowly releases nutrients into the mix, which will help to feed seedlings as they grow. You can use your own garden compost, or buy some in. Break up clumps with your hands or, better still, screen or sieve the compost to get a fine, even texture.

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