The Case for Coir

By Christine Freeburn, Master Gardener

For many years, we have been told of the depleted bogs where peat has been harvested and why we should not be buying it. Many gardeners wonder what they would use to replace this product that is a great soil amendment and seed starting medium.

Peat is an organic naturally forming product which can take hundreds of years to replace. We all know the history of peat bogs in the British Isles when peat was used to heat homes and then mined irresponsibly, destroying wetlands and ecosystems. The International Union for Conservation of Nature (IUCN) is a group which is responsible for setting up a Peatland Programme in the UK.

Peat harvesting

Did you know that Canada is the largest producer and exporter of horticultural peat, with about 1.3 million tonnes of peat being mined in 2010? Peat companies must, however, follow federal and provincial guidelines. Just recently, in Manitoba, this ruling occurred: On January 20th, 2023, Moswa Meadows and Fish Lake Fen were designated as provincially significant peatlands in the newly created Provincially Significant Peatlands Regulation in order to ensure the biodiversity of the two areas is preserved. Specified development activities, including mining, forestry, agriculture, and peat harvesting, are now prohibited across the nearly 28,000 hectares that make up Moswa Meadows and Fish Lake Fen and will ensure the areas can continue to provide long-term beneficial goods and services including carbon sequestration and storage, water filtration, and flood mitigation. For more about peat management in Canada, check out

Peat Mining in Manitoba

Coir  (pronounced COY-er) comes from the coconut plant.  It is the part between the meaty white flesh and the hard outer shell. Because coconuts are grown and harvested for food, coir is readily available. India is the largest exporter of coir. It can be used on its own as a growing medium for seed starting and root cuttings or as a soil amendment for holding moisture and is a great replacement for peat.

Sample package of coir

Coir has a pH of 5.7 to 6.5 which is perfect for plants to obtain nutrients. It can be used in containers to help hold moisture and lighten soil. The square foot garden formula is one third peat moss, vermiculite and compost, so coir would be an excellent peat replacement. Coir last longer than peat, being slower to breakdown. It has no odour. It gives sandy soil more structure. Excess salt may be a problem, however, rinsing with fresh water a few times should remove enough of the salt.

Coir is available in many different ways including bales, bricks, pots and discs. Compressed blocks need to have warm water added for it to absorb and expand, just like peat. Place the brick in a bucket, add water and watch it expand. The coir will absorb the water, and can expand by up to 15%. It will soften and have a fluffy texture which can then be placed in pots for planting slips or rooting plants. The small disks also need to have water for them to expand and act like the peat pods we are familiar with. And like the peat pods, these coir disks can be planted directly into the garden. Check out this article:  What is Coconut Coir?

Coir products are available online at many sites like Veseys Seeds. I have also found them in Peavey’s and Home Hardware in Peterborough. Let’s all be responsible by purchasing coir rather than peat.

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