Mother Earth #4 Perlite - 4cu ft - 1in

Coarse-Granule Sterile Perlite for Heavy-Drainage Applications, Grade #4

Large containers, orchid mixes, and bottom-of-pot drainage layers all need an amendment that moves water through fast without collapsing under its own weight over time. Mother Earth #4 Perlite is the largest granule grade in the line, kilned from naturally occurring siliceous rock and expanded up to 20 times its original volume to approximately 1in granules.

At 4cu ft per bag, this grade is sized for heavy-drainage applications such as large container mixes, orchid blends, and drainage layers, where a finer perlite grade would settle and pack down faster under repeated watering.

Key Features & Benefits

• Expands Up to 20x When Kilned — produces a lightweight, sterile growing media from raw rock
• Neutral pH of 7.0 — will not shift the pH of the growing mix it is blended into
• Approximately 1in Granules — the largest grade in the line, built for heavy-drainage applications
• Hydroponics Compatible — works as a rooting and germination medium

Who Should Use Mother Earth #4 Perlite

Growers building large container mixes, orchid blends, or drainage layers that need to move water fast without packing down over time will find #4's larger granule size holds up best under those conditions.

About Mother Earth

As a growing-media brand, Mother Earth covers potting soils, coco coir, and perlite through Hawthorne Gardening Company's branded product pages. Grade #4 is the largest granule size in its kilned perlite lineup, above both the fine Coarse grade and the mid-size #3 grade.

Frequently Asked Questions

How large are #4 Perlite's granules compared to the other grades?

They run approximately 1in, making #4 the largest granule grade Mother Earth offers, above both the Coarse grade (1/8 to 1/4in) and the #3 grade (around 1/2in). That size is chosen specifically for applications that need maximum drainage.

What applications is #4 Perlite best suited for?

It works well in large container mixes, orchid blends, and bottom-of-pot drainage layers, where fast water movement matters more than fine, even texture. A finer grade would settle and compact faster under the same heavy watering.

Is #4 Perlite sterile like the other grades?

Yes, the same kilning process applies across all of Mother Earth's perlite grades, sterilizing the raw siliceous rock as it expands up to 20 times its original volume. Granule size is the only variable that changes between grades.

Does the larger granule size affect the pH of my mix?

No, #4 Perlite holds the same neutral pH of 7.0 as Mother Earth's other perlite grades, regardless of granule size. It will not shift the pH of the soil or soilless mix it is blended into.