Perlite is a naturally occurring, non-toxic volcanic rock. It is heated to very high temperatures to produce a lightweight micro-porous material. Perlite is used in horticulture as a soil amendment. Because of its high permeability / low water retention it helps to prevent soil compaction. Available in 10ltr and 100ltr bags
- Perlite is ideal for use when sowing seeds, rooting cuttings, potting on and container growing.
- Will give a limited amount of frost protection to roots
- Prevents compaction - improves aeration and drainage.
- Does not decompose - lasts for years.
- Stimulates root initiation and vigorous growth.
- Almost neutral pH.
- Holds moisture but does not become soggy.
- Perlite is free from disease, weeds and insects
- Perlite is used wholly or partly in place or sand or grit in potting compost where it improves aeration, draining and insulation, and also facilitates re-wetting. Perlite speeds up rooting and reduces the risk of damping off. It provides an optimum balance of air and water - makes water logging almost impossible
- Improves the texture of heavy silt or clay soils by increasing aeration and drainage.
- Perlite improves aeration and drainage in compacted and poorly drained areas on old lawn and also helps the establishment of new grass. Perlite will greatly assist the air-moisture balance and ensure better root development and grass (lawn) growth. Use a hollow tine spike all over the affected area, then spread a thin layer (2-5mm) of damp perlite pre-mixed with a suitable fertilizer. Rake or brush evenly, and water thoroughly. Note: a 100 litre bag of perlite will give on average a 2mm layer over 50 sq.m.
Perlite v Vermiculite
- Perlite is better than vermiculite at improving aeration. Including perlite will create a mix that has more macroporosity. That is the spaces between perlite particles are big enough to allow water to drain through them whilst also allowing for water-retention and the effects of capillary action in small surface crevices.
- Vermiculite is a better water-holder. Vermiculite is more sponge-like and has a higher water holding capacity than perlite. Perlite particles can only hold moisture in the small bubbles on their surface
- For seed germination, where near-permanent moisture is required, vermiculite is ideal. Seeds germinate and grow much better in moist conditions and for this reason vermiculite is a good medium for germination.
- Perlite is better for cuttings due to to its high macroporosity. Cuttings tend to benefit from having access to lots of oxygen as well as water
- As an addition to a potting mix: vermiculite for increasing water-holding capacity, perlite for improving drainage (air porosity).