What Does Perlite Do in Potting Soil?
Agricultural Gardening Horticulture Perlite

What Does Perlite Do in Potting Soil?

If you’re an avid gardener, you’ve likely come across the term “perlite” when shopping for potting soil. But what exactly is perlite, and why is it used in potting soil? In this article, we’ll explore the role of perlite in potting soil and how it benefits your plants. We’ll also discuss the different types of perlite and where you can find it.

What is Perlite?

Perlite, a form of natural volcanic glass related to obsidian, undergoes expansion upon being heated to high temperatures. The heat triggers the rock to swiftly expand, forming a frothy mixture of minuscule, light glass bubbles joined together to form larger granules, varying in size from the width of a human hair to the tip of a finger.

Perlite is commonly used in horticulture, construction, and industrial applications due to its lightweight and insulating properties. In gardening, its main use is to enhance soil structure, hold moisture, and improve oxygenation by increasing the number of pores spaces in the soil.

While there are different types of perlite for different applications, in gardening mainly horticultural perlite is the type that is most often used.

Horticultural perlite is the most commonly available type and is made by heating and expanding natural perlite. It is often used in potting soil mixes and is readily available at most gardening stores.

What Does Perlite Do?

Improves Soil Aeration

Improves Soil Aeration Image

One of the main benefits of perlite in potting soil is its ability to improve soil aeration. The tiny particles of perlite create air pockets in the soil, allowing for better drainage and oxygen flow to the plant’s roots.

This is crucial for potted plants, which can quickly become waterlogged in confined spaces. Perlite helps by enhancing soil drainage, preventing root rot and related issues.

Good soil aeration plays an additional role by promoting healthier soil biology. When beneficial bacteria and microbes in the soil have access to fresh air and oxygen, and metabolic waste gasses produced have more pathways of escape to prevent them from building up, then plants will benefit from improved conditions in the soil. Beneficial bacteria will increase the rate of mineralization of nutrients, and the whole soil food web benefits, leading to healthier root development, vegetation and flowering of each plant. 

Retains Moisture

While perlite is known for its ability to improve drainage, it also has the unique ability to retain moisture. The porous structure and rough surface of perlite allows it to absorb and hold onto water, making it an excellent addition to potting soil for plants that require consistent moisture.

This proves particularly advantageous for plants susceptible to rapid drying, like succulents or herbs. Adding a degree of small-to-medium-sized Perlite particles in the soil assists in retaining moisture for extended durations, diminishing the frequency of required watering.

Prevents Soil Compaction

Eventually, potting soil may compact, hindering root growth and nutrient absorption for plants. Perlite helps prevent this by keeping the soil loose and airy, allowing for better root growth and nutrient absorption.

Stores Nutrients

Perlite is a naturally occurring mineral and itself does not contain any nutrients. Nonetheless, it possesses the capability to retain nutrients in suspension in irrigation water and gradually release them, which can be advantageous for plants needing a constant nutrient supply, aiding in the prevention of nutrient shortages.

Lightweight and Easy to Handle

Soil and Perlite Image

Another advantage of using perlite in potting soil is its lightweight nature. This makes it easy to handle and mix into soil, even for larger pots or containers. It also makes it a great option for rooftop or balcony gardens, where weight restrictions may be a concern.

Where Can I Find Perlite?

Perlite is widely available at most gardening stores and can also be purchased online. When shopping for perlite, be sure to check the label to ensure it is horticultural or organic perlite, as other types may not be suitable for gardening.

You can also find perlite at your local nursery or garden center. If you’re unsure where to find perlite near you, a quick online search for “perlite near me” should provide you with a list of nearby retailers.

How to Use Perlite in Potting Soil

Perlite is commonly mixed into potting soil in proportions of 1:4 or 1:3, which means one part perlite for every three or four parts of other soil components. (such as potting soil, peat moss, coco coir, or compost). This might differ based on the species of plants being cultivated and their unique requirements. Cactus mixes in particular take a higher mineral content, so be sure and research the best mix ratio for your plant and growing conditions.

To use perlite in potting soil, simply mix it in with the soil before planting. Be sure to thoroughly mix the perlite into the soil to ensure even distribution.

Other Uses for Perlite in Gardening

While perlite is most commonly used in potting soil, it can also be used in other gardening applications. Here are a few other ways you can use perlite in your garden:

Seed Starting

Fine or medium sized seedling grade Perlite is an excellent medium for starting seeds. Its lightweight and airy structure provides the perfect environment for seedlings to grow and develop strong roots. Usually used in combination with peat moss or other organic growing media.

Hydroponic Gardening & Propagating

Hydroponic gardening involves cultivating plants in a soil-free environment, utilizing a nutrient-enriched water solution. Perlite is often used as a growing medium in hydroponic systems, as it provides excellent aeration and drainage for the plants without introducing excess organic content into water circulating systems.

New cuttings from indoor plants are regularly propagated in moistened perlite and nothing else because it maintains a balanced air-to-water ratio, and is a sterilized growing environment.

Outdoor Soil Amendment

Beyond potting soil, perlite can serve as a soil enhancer in garden beds as well. Simply mix it into the soil to improve aeration and drainage.

Perlite Outdoor Soil Amendment Image

FAQ: Get Growing with Supreme Perlite

1. Should you mix perlite into a potting mix?

Definitely! Adding perlite improves drainage and air flow, making roots happy. Pre-packaged compost mixes often do not contain any perlite, and are in need of the addition of perlite to lower their density, and add pore spaces for drainage and aeration. Store-bought potting soil may only contain very small pieces of perlite, or not enough perlite to really provide any benefit to your plants.

2. Can you add too much perlite to soil?

Yes, too much perlite can lead to soil that dries out too quickly. Be sure to select the right size of perlite for the container and soil you are working with, and check the recommended soil conditions for the type of plants you are growing. Also take into consideration the local climate (relative temperature and humidity), as well as whether or not the plants will be indoor or outdoor, and how much you plan to water them. 

3. Do plants thrive more with perlite?

Yes, plants often grow better with perlite because it helps soil stay aerated and well-drained, but retain just the right amount of moisture.

4. Is there such a thing as too much perlite in potting mix?

Adding too much perlite may cause the soil to dry out quickly as it won’t retain enough water for plants. Consider your plant’s specific needs, local climate, and whether it will be indoors or outdoors when adjusting the soil mix.

5. Can perlite help stop root rot?

Absolutely! Perlite improves drainage, helping prevent waterlogged soil that causes root rot.

Unlock Plant Potential: Discover the Magic of Perlite in Gardening

Perlite is a versatile and beneficial addition to potting soil. Its capacity to enhance soil oxygenation, maintain moisture, avoid soil compression, and supply nutrients renders it an invaluable asset for gardeners.

Regardless of whether you’re germinating seeds, cultivating plants in containers, or tending to a garden bed, perlite can contribute to the betterment of your plants’ health and development. So next time you’re shopping for potting soil, be sure to look for one that contains perlite for optimal plant growth.

Perlite is a game-changer in gardening. It keeps your potting mix aerated, helps retain the right amount of moisture, and prevents soil compaction. Whether you’re potting new plants or looking to give your garden soil a boost, adding Supreme Perlite can make all the difference. Ready to see healthier growth in your garden? Pick up Supreme Perlite today and watch your plants thrive. Get started now and give your plants the best environment to grow!

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