What is perlite?
Perlite is a tiny white particle that can be seen in many potting soils. Many new growers don't know their exact use, nor do they know that it doesn't exactly qualify as a growing medium.
Purpose of perlite
Perlite, like coco coir, has a neutral pH. It is very useful in increasing drainage, aiding aeration, and reducing compaction when you add it to potting soil. It isn’t renewable, but it is definitely reusable. Unlike Rockwool and clay pebbles, perlite does not absorb nutrients. This allows growers to simply sterilize it and use it again in a fresh grow medium.
Perlite works well with both hydroponic and traditional soil growing. It increases a plant’s ability to absorb water and oxygen. You can use its compaction ability to prevent nutrient lockouts providing added protection to the roots.
How to make perlite soil?
On its own, perlite doesn't exactly qualify as soil. You can make perlite soil by purchasing potting soil and mixing it with perlite. Given its ability to increase aeration and drainage and reduce compaction, growers recommend using perlite with numerous garden soils. You can learn more about making your own soil by giving our super soil recipe a read.
You can also check out our detailed article on the garden soils at our learning center to increase your gardening knowledge.
How much perlite should be added to the soil?
The answer to this question depends on the type of soil you are using. As a general rule, perlite concentration can be anywhere between 10% and 40% of the total soil volume. For better water retention, 10-20% perlite is ideal. If you feel like the soil has started to retain more water than needed, simply add more perlite.
Vermiculite vs. perlite
Vermiculite is a great alternative to perlite. It offers better water retention and is as good as perlite at aeration, making it a very popular seed-starter medium. Our blog on vermiculite vs. perlite can help you increase your knowledge base on the topic.