Dying wood chips for use in an indoor or outdoor garden can be a labour-intensive task. Wood chips will readily take almost any stain or dye, but if the dye is not fixed, then you risk having the colour bleed out of it or fade. Soaking wood chips in a dye to colour them is easier than trying to stain them with an oil-based stain that needs to be wiped or brushed on.
Place 1 tbsp of a fibre reactive procion dye and 1/2 cup of plain salt per gallon of water you add into a 5-gallon dye bucket. Three gallons of water (with dye) will give you room to dye about 0.907kg. of wood chips. Mix it thoroughly. Water-based dyes will work, but can bleed and fade. A fibre reactive dye will require a soda ash fixative to prevent the wood chips from fading quickly.
Dissolve 1/3 cup of soda ash in hot water for each gallon of water you added to the bucket. Pour the soda ash solution into the dye bucket.
Place the wood chips in your dyebath and leave them for up to 2 hours or until they turn the colour you want.
Rinse the chips under cold running water.
Spread out the dyed chips on a towel or tarp to dry.