We usually come across the term perlite when we talk about indoor plants or succulents or when we buy plants from the shop, and we see this white substance in soil, which looks like tiny Popcorn pieces. Well, that is nothing but PERLITE. So, let’s learn more about what it is and perlite benefits in gardening.
Perlite is a form of naturally occurring amorphous volcanic glass which can store a lot of water in itself. Like most other materials of volcanic origin, it is grey and black with a mix of different colours and is very dense and heavy in its original state.
But the perlite that we get from the shops is much lighter in weight and appears white in colour instead of black or grey. So, what makes this perlite so light, and how does it get so lightweight?
What is perlite made of
This volcanic glass is mined and heated to a range of 850-900oC, causing the mineral to soften. This process lets the water trapped in the volcanic glass vaporize and escape. This leads to the expansion of the glass to 7-16 times its normal volume and the remaining trapped air changes the colour from dark to brilliant white due to the reflectivity of the remaining water inside the glass. In addition, this newly created material is much lighter in weight with numerous pores and cavities, which helps retain the water required by the plant roots while draining the excess water.
Perlite is sterile and has a neutral pH ranging between 6.6 to 7.5, and that’s why it can be used for any soil type. It contains 70-75% silicon with a few other mineral oxides such as sodium, aluminium, potassium, iron etc. Perlite comes in many different grades like Fine Perlite, Medium Perlite and Coarse Perlite. Medium Grade perlite is most suitable for houseplants, flowerbeds, starting seeds and propagation mediums. Coarse perlite offers superior drainage due to its highly porous nature and bigger size.
Perlite is NOT a chemical fertilizer, and therefore, it does not contain any harmful compounds making it completely safe to use in organic gardening. In other words, perlite is non-toxic.
USES OF PERLITE
PERLITE TO PREVENT ROOT ROT
As mentioned earlier, perlite creates a filtration system that allows the excess water to drain through the pot’s holes, which keeps the soil moist and not soggy. This reduces the growth of unhealthy bacteria in the soil, preventing the development of root rot. You can add perlite in the soil depending upon the needs of the plant. For example, water-loving plants such as Peace lily, Syngoniums, Ctenanthes, Calatheas etc. love moist and humid conditions. Therefore, you can keep the ratio of Soil: Perlite as 80:20 whereas the plants such as succulents, Snake plant, ZZ plant etc., prefer more airy soil and therefore for these plants, you can keep the ratio as 60:40 or 50:50.
PERLITE FOR HEALTHY PLANT AND ROOT SYSTEM
Due to the highly porous nature of perlite, it breaks Soil compaction and traps a lot of air which allows the roots to breathe inside the soil. It helps maintain a balance between air and moisture inside the soil, assisting in healthy root growth. A healthy root is equal to a healthy plant. Perlite for growing plants is good for growth.
PERLITE AS A COVERING MEDIUM
Covering the seeds and seedlings with a thin layer of perlite will help in the following ways: –
- It will maintain the soil temperature during the day and night, making sure that the seed or the seedlings remain warm enough to germinate and grow easily.
- It also allows enough light to pass through, which is essential for the tiny little leaves to photosynthesize and grow healthy.
- A thin layer of perlite will keep the soil moist by not letting the evaporation process happen. In addition, moist and warm soil conditions will enhance the germination process.
- It will also protect the seeds and seedlings from pest attacks such as slugs, snails, fungus gnats, caterpillars, etc.
Perlite can also be used for outdoor plants, snake plants, and other vegetable plants like pepper, tomato plants and all other plants. Some people think the overuse of Perlite burn plants, but that is not the case. Perlite is not a fertilizer or toxic, so it won’t burn your plants.
Some people ask me “how to add perlite to already potted plants”, the answer is you need to repot the plant with perlite mixed soil.
Perlite is easily available to buy at Amazon or any other local garden supplies shop.
PERLITE FOR PROPAGATION OR AS A SEMI HYDROPONIC MEDIUM
Propagating your plants in perlite and water will help to develop a more robust and healthier root system. In addition, the transition of the propagated cutting from water to the soil will be much easier. The plant and its roots will be able to adjust much quicker in soil when propagated in perlite and water instead of just water.