PlantCoco coir.
A growing medium made from the pith and fibres of coconut husks, sold as fine pith, fibre or chips.
What it means for your plants
Coir has a pH of about 5.5–6.8 and holds water well while staying reasonably airy. Choose washed, buffered coir, since unwashed material can carry high sodium and potassium; compressed bricks expand 5–7 times in volume when soaked.
IN PRACTICE
A 650 g coir brick soaked in about 4 litres of warm water yields roughly 8–9 litres of loose medium.
Put it into practice
Peat is acidic and holds 10–20× its weight in water; coir is near-neutral but can carry salts. Compare pH, rewetting, nutrition and sustainability for houseplant mixes.
Coco coir vs. peat moss: how each behaves in your pots
