COIR VS PEAT
Two growing media that behave differently in the pot, and why the choice matters more than most spec sheets suggest.
They come from different sources
Coir is made from coconut husk. The husk is separated into two useful fractions: coco coir, the coarse long fibre that gives structure and drainage, and coco peat, the fine spongy dust that holds water. When a supplier says "coir" they may mean either fraction or a blend of both.
Peat is partially decomposed plant matter harvested from bogs. It is a finite resource. Coir is a by-product of the coconut industry, so it is renewable.
pH: the number that matters most
Peat is acidic, typically pH 3.5 to 4.5. Coir is close to neutral, typically pH 5.5 to 6.8. That difference is not academic. A crop grown in peat usually needs lime or another pH adjustment before or during production. Coir often does not.
| Property | Coir | Peat |
|---|---|---|
| pH | 5.5 to 6.8 | 3.5 to 4.5 |
| Water retention | 73 to 80 percent of volume | 60 to 68 percent of volume |
| Rewetting when dry | Fast, reabsorbs readily | Slow, can shed water |
| Source | Coconut husk, renewable | Bog peat, finite |
Water retention and rewetting
Coir holds more water by volume than peat, but the more important difference is what happens when the material dries out. Peat becomes hydrophobic when dry and can be difficult to rewet. Coir rewets faster and more evenly. In a production setting that means less water waste and less stress on the crop during dry-down cycles.
When to use which
- Coir for most container crops, hydroponic systems, and any situation where pH stability and rewetting matter.
- Peat for acid-loving crops such as blueberries and azaleas, or where a buyer specifically requests it.
- Blends are common. A coir-peat blend can balance water holding with the lower pH some crops prefer.
What we supply
We supply coco peat and coco coir as separate fractions and as blends, washed and buffered using OMRI-approved methods, in compressed blocks, loose bulk and bagged formats. Tell us the crop, the container size and the water retention target, and we will recommend the fraction and ratio.