If you are a plant lover and adore indoor plants, you must be familiar with pumice and perlite and their use in keeping plants healthy and happy.
But even if you don’t, there’s no need to worry because we’ve got you covered!
Both perlite and pumice have their benefits and disadvantages. Choosing one or the other depends solely on your personal preference, budget, location availability, plant, and soil type.
Overwatering and poor drainage have been some of the most common causes of plant death so far. To avoid this, gardeners all around the globe use either pumice or perlite.
Although it seems confusing to make a choice, don’t worry we've got your back!
Featured images by: Calibonsai & cfbshop from Etsy.
Contents
Factors to Consider Before Making a Choice
- It is important to know their composition, characteristics, availability, and accessibility to make a choice.
- Also, never forget to consider your plant type and preference before choosing anything for them.
- If you are eco-friendly (which all of us should be), it’s better to know if your choice is good for the environment too.
The greater the processing a product needs, the bigger the carbon footprint it has!
Carbon footprint accounts for the greenhouse gases released during the processing, which leads to an increase in global warming.
Let’s break down the two options in detail, for you, to make an easy choice. So let’s dive in!
Pumice- Basic Features:
Below are all the characteristics of pumice, including the pros and cons.
Formation
Pumice (aka, solidified rock foam) is formed during the abrupt cooling of lava after the volcanic eruption. Due to this, tiny air bubbles are trapped inside, making the pumice extremely porous.
The porous structure allows pumice to be lightweight and ensures excellent drainage, along with making it a preferred habitat for microbes.
Composition
Pumice is mainly composed of silicon oxides and aluminum oxides. It may contain traces of metal oxides, calcite, or salts.
Production
Although the hotspots for mining pumice are not defined, countries including, US, Turkey, Iran, Italy, and Greece are leading producers of pumice.
Colors
Pumice is available in varying colors from dusty white to pale yellow and pale grey, depending upon their mining site.
Processing
Pumice mining is less abrasive and is considered environment-friendly.
When it comes to processing, pumice is comparatively hassle-free as the volcanic eruption deposits them on the surface of the earth and no processing, other than breaking it into smaller pieces, is required.
Size
They are available in a variety of sizes, however, for gardening, ⅛” to ⅓” size is used.
Uses
Apart from construction purposes and soil amendments, they are also used for decorative purposes.
For heavier and taller plants, pumice is an excellent choice as it maintains aeration and drainage while keeping the plant from tipping off.
Gardener tip: If you are working with sandy soils, pumice is always the better option.
Decomposition
Pumice doesn’t decompose for a very long period of time. This not only makes it a long-lasting option but also helps maintain soil structure and aeration, over a long period of time.
Challenges
Apart from all the plus points, there are a few constraints when it comes to pumice:
Pumice is quite expensive and not easily available at local stores, everywhere.
Also, fine particles or pumice are dusty and can cause irritation to the eyes, nose, and throat.
Pumice- Pros. & Cons.
| Pros. | Cons. |
| Provides excellent aeration and drainage | Fine particles are dusty |
| Lightweight, porous | Expensive |
| Neutral pH | Not easily available in all areas |
| Environmental-friendly | No specific hot spots for mining |
| Good for heavy and tall plants | |
| Preferred for sandy soils | |
| Requires minimal processing | |
| Lasts long |
Perlite- Basic Features:
Below are all the characteristics of perlite, including the pros and cons.
Formation
Like pumice, Perlite is also a volcanic derived, amorphous rock that is formed by the cooling of molten lava.
Composition
Perlite (aka, sponge rock) is a silicon mineral containing traces of aluminum, iron, sodium, and potassium oxides.
Production
Countries such as the US, Japan, Turkey, and Greece list among the leading producers of perlite.
Processing
Prior to commercial use, perlite needs to be processed. The volcanic glass is mined, crushed, and then heated at an extremely high temperature ranging from 1500 to 2000℉.
Upon heating, the crushed particle pops up, increasing approximately 20 times its size. Resulting in the white color pebbles, you are familiar with.
Colors
Naturally, perlite is available in a number of colors such as grey, brown, black, red, blue, and green, etc. After the processing, it appears white or light grey.
Sizes
Commercially perlite is available in 3 sizes, i.e., coarse, medium, and fine. Where the thickness ranges from 0.02 to 0.3 inches, approximately.
Uses
Pumice is widely used for construction, insulation, and plaster. Apart from that, it is loved by gardeners and indoor planters as a soil mix for both outdoor and indoor plants.
It is lightweight, ensures aeration, and prevents water logging which allows the plants to breathe properly.
For horticulture purposes, coarse perlite is better suited for aeration and drainage, whereas fine-sized perlite is better penetrated the soil.
Gardener’s tip: Use bigger particles for larger pots and finer particles for smaller pots
Decomposition
Perlite, similar to pumice, does not decompose for a very long period of time. This is because it is composed of extremely heated volcanic rock.
Adding perlite (or pumice) to a soil permanently changes its structure and therefore they are a smart choice for plants that need frequent repotting.
However, if taken in comparison, Perlite decomposes faster than pumice (still taking eons of years).
Challenges
Perlite is inexpensive and easily accessible, however, there are a few challenges associated with it.
The weight and porosity of perlite can cause it to float in water and you can easily see it making its way to the top of your potting soil.
Also, perlite is lightweight and thus can be easily blown by the wind. Perlite is also less efficient when it comes to heavier plants.
If used in fine-sized particles, perlite can be dusty and cause irritation to the eyes and breathing. To avoid discomfort, make sure to wear a mask while handling perlite, especially if you have breathing issues.
Gardener’s tip: When working with perlite, use a mix of heavier pebbles to weigh down your soil.
Perlite- Pros. & Cons.
| Pros. | Cons. |
| Provides excellent aeration and drainage | Floats in water |
| Lightweight, porous | Less efficient in preventing heavy plants from tipping over |
| Pocket friendly | Fine particles are dusty |
| Easily available | Requires processing |
| Available in a variety of sizes | Can be blown away by the wind |
Click here to purchase 100% pure perlite from Etsy.
Pumice vs Perlite - A Quick Comparison
We hope that the above-detailed analysis of pumice and perlite will help you make a decision. However, if you are still confused here’s a quick sneak peek of perlite vs pumice to give you a bird’s eye view:
| Characteristics | Pumice | Perlite |
| Composition | Silica, (traces of) metal oxides, calcites, or salts | Silicon dioxide(SO₂), (traces of) aluminum, iron, sodium, and potassium oxides. |
| Producing Countries | US, Turkey, Iran, Italy, and Greece | US, Japan, Turkey, and Greece |
| Processing | Requires minimal to no processing | Crushed and melted at 1500-2000℉, prior to use |
| Natural Colors | Dusty white, pale yellow, pale grey | Red, green, brown, blue, black, grey |
| Commercial Colors | Dusty white, pale yellow, pale grey | White, light grey |
| Horticulture Size | ⅛ to ⅓ inches | Coarse, medium, fine (0.02-0.3 inches) |
| Horticulture Uses | AerationPrevent waterlogging prevents heavy & tall plants from tipping encourages microbial growth. | Ensure aeration, Ensures proper drainage, Prevent waterlogging, Decorating soil |
| Other Uses | Construction, Soaps, and cleaners | ConstructionInsulationPlaster |
Pumice vs Perlite- Our Two Cents
Both perlite and pumice have their benefits and disadvantages. Choosing one or the other depends solely on your personal preference, budget, location availability, and plant and soil type.
However, if it’s on us, the winner is a no-brainer. Clearly, the qualities of pumice outweigh those of perlite.
So, for us, the winner of the debate is pumice! (*drumrolls*)
As far as the limited availability of pumice is concerned, internet and online marketing is your key.
No matter where, you can get your pumice shipped to your doorstep, in just one click.
However, you do what your heart says, because it may be on your left, but it’s always right for you!