Horticultural Pumice

Horticultural Pumice

Horticultural Pumice is the lightweight volcanic rock orchid growers and bonsai enthusiasts mix into potting media when drainage and aeration matter. Mined and washed in New Zealand's Lake Taupo region.

Potting mix staying wet too long?

Heavy soil that takes days to dry out. Roots sitting in water. That sour smell when you tip a plant out of its pot. Compacted media where nothing drains and roots can't breathe.

Air pockets without the weight

Pumice is full of tiny air spaces that let water drain freely while still holding moisture in the pores. Your plants get steady moisture without sitting wet. Roots stay aerobic instead of rotting.

It's light — a fraction of the weight of gravel or sand — so pots stay manageable. And because it's hard volcanic rock, it won't break down or compact like perlite or bark. It just sits there doing its job for years.

Three grades available depending on what you're growing. The 1–2mm works for seed raising and fine-rooted plants. The 1–7mm is the general-purpose size most people use. The 7–20mm suits drainage layers in large pots or mixes for cacti and succulents.

How to Use It

Can also be used as a top dressing to reduce evaporation and keep the surface from crusting.

Good to Know

This pumice is washed and screened to remove fine particles. Unwashed pumice includes "fines" that cause the mix to set like concrete and hold too much water — the opposite of what you're trying to achieve.

Popular with orchid societies, bonsai clubs, and commercial propagators who need consistent drainage across thousands of pots. The pumice can be reused — just rinse it and it's ready to go again.

At a Glance