Perlite

Perlite FAQs

Below, we've covered a few handy things to know about using, storing and making the most of perlite in your garden.

What is perlite?

Perlite is a lightweight, porous mineral material commonly used in gardening and horticulture. It is made by heating naturally occurring volcanic glass until it expands into lightweight, white granules.

Its porous structure makes perlite particularly useful for improving drainage and aeration in compost and growing media, helping create healthy conditions for developing roots.

Where can I use perlite?

Perlite can be mixed into a wide range of composts and growing media to improve drainage and airflow around plant roots. It is particularly useful for plants grown in pots and containers where good drainage is important.

It can also be used for seed sowing, propagation and rooting cuttings, as well as when potting up plants that prefer a lighter, more free-draining growing medium.

What are the benefits of using perlite?

Perlite helps create a lighter, more open growing medium by improving drainage and allowing air to circulate around plant roots. This can help reduce the risk of compost becoming overly wet and creates favourable conditions for healthy root development.

Because it is lightweight and porous, perlite can also improve the structure of heavier or more compact growing media without adding significant weight to containers.

Can I use perlite for seed sowing?

Yes, perlite can be useful when sowing seeds and raising seedlings. Mixing a suitable amount into seed compost can help improve drainage and aeration, creating a loose structure that allows developing roots to spread more easily.

Perlite can also be used as a light covering for some seeds, although the exact approach will depend on the requirements of the plants you're growing.

Can I use perlite for cuttings?

Perlite is useful for propagating cuttings, as its porous structure provides good aeration and drainage around developing roots. It can be used on its own for certain propagation methods or mixed with other growing materials to create a suitable rooting medium.

Keep the medium appropriately moist while cuttings establish, taking care not to leave it waterlogged.

What is the difference between perlite and vermiculite?

Perlite and vermiculite are both lightweight horticultural materials, but they have different properties. Perlite is primarily used to improve drainage and aeration, while vermiculite is better at retaining moisture.

Perlite is therefore particularly useful for plants that prefer free-draining conditions, while vermiculite can be beneficial when consistent moisture retention is more important. They can also be combined with compost to create a balanced growing medium.

How much perlite should I use?

The amount of perlite required will depend on the plant and the growing medium you're using. A small proportion mixed into compost can improve drainage and aeration, while plants that require particularly free-draining conditions may benefit from a higher proportion.

Always follow the instructions supplied with the particular perlite product and consider the drainage requirements of the plant you're growing.

How should I store perlite?

Perlite is simple to store between uses. Keep it in its original bag or a sealed container in a dry, sheltered location such as a shed or garage. Protect it from rain and excessive moisture to keep it dry and easy to handle.

When handling dry perlite, avoid creating unnecessary dust and follow any safety guidance provided on the product packaging.

Why buy Perlite from Marshalls Garden?

Your Trusted Gardening Experts

We’re more than just a team — we’re your gardening experts, here to provide trusted gardening advice, helpful guidance and expert support for all your gardening needs. Whether you’re an experienced gardener or just getting started, we’re here to help you grow with confidence.

Explore our extensive collection of gardening guides, developed from our years of gardening experience since we were founded in 1948. From growing tips and plant care advice to seasonal gardening inspiration, our resources are designed to help you get the most from your garden.

Have a question about plants, seeds or gardening products? Our friendly team is available Monday to Friday. Get in touch to discuss our product range or chat with us about all things gardening.

When you order from us, you can expect a fast and reliable service. In-stock plants and seeds are dispatched within two working days, and all our packaging is recyclable, helping you make more sustainable choices for your garden and the environment.

You can shop with confidence knowing that our reputation is built on the experiences of our customers, with thousands of five-star Trustpilot reviews and a 100% happiness guarantee across our products.

We’re not just here to sell gardening products — we’re here to share our knowledge, support your gardening journey and help you grow with confidence.