Written by Ivy
Dec 16 2022
Determining how to best improve aeration and drainage for your plants requires weighing the pros and cons of pumice and perlite.
Although both are almost equally effective at enhancing your soil, they differ from one another in terms of price, carbon footprint, and porosity.
To help with the pumice vs. perlite debate, we'll look at what each one is, check the main difference, show you some pros and cons, and also reveal if you can use any substitutes. Before purchasing either of them, we want to make sure you are informed of all the details.
Pumice is an element you'd add to bonsai soil to assist with aeration and drainage. Although it is made of volcanic rock, the fact that it is available in small sizes makes it easier to transport. The substance is porous by nature, which is how you can recognize it in its natural setting.
Besides its use in bonsai soil, there are plenty of other applications. For instance, a lot of people use it as a top-dressing on top of the soil in gardens and bonsai pots to stop evaporation. Additionally, when creating a miniature landscape, it is used as decorative pebbles. It's employed as insulation in the building sector.
As perlite is a mineral that's created from volcanic glass, it has more of a sponge nature. About 70% of it is silicon dioxide, with the remaining parts being iron oxide, sodium oxide, potassium oxide, and aluminum oxide. The substrate becomes porous after going through human-made machinery for processing.
Since it aids so much with aeration, you'll usually find perlite in succulent or bonsai pots that don't need as much water retention. Jade and Crassula trees are a couple of examples of bonsai plants that are succulent in nature. Additionally, hydroponics can benefit from it.
Let's look at a quick comparison of the two.
|Color||Pure white||Black or grey|
|Porosity||Very porous and light-weight||Comparatively less porous, heavier|
|Mined From||Mostly from United States, Turkey, Japan, and Greece||United Staes, Mexico|
|Processing Required||Less processing required||Less processing required|
|Eco-friendly||More eco-friendly||More environmentally friendly|
|Heat required for processing||1700 degrees Fahrenheit||About 1500 degrees Fahrenheit|
The main difference between pumice and perlite is that pumice is white in color, more porous, and more expensive. Contrarily, perlite requires more processing and has a higher carbon footprint despite being more widely available.
Pumice, a volcanic rock mineral widely used in gardening, is a wonder ingredient best used for dramatically improving the soil's drainage and helping flush out toxins. Additionally, it does a great job of holding onto moisture and giving the ground a small amount of trace nutrients.
Learn more about these advantages, as well as others, in the sentences that follow.
The soil is made more porous by pumice particles, which also open up channels for water to quickly drain. Their porosity is very helpful because adequate water drainage is the most important property that a potting soil needs to have. This trait stops water from unnecessarily building up in the soil and causing rot and other diseases.
The rapid growth of rot-causing fungi and bacteria occurs almost always as a result of water retention in the soil. This extra water is damaging to the plant, too, as it also produces swollen stems and leaves.
Drainage is imperative for another purpose as well: that of flushing out toxins and minerals from the soil every time you water it. Regular fertilizing causes these harmful substances to inevitably be created and remain in the soil. Pumice will be a huge help in getting rid of them.
While pumice does look like a dry rock, tiny microscopic pores on its surface can also absorb water. It has been found to hold onto moisture for up to 48 hours straight. For plants like succulents that can withstand drought, that is an excellent quality to have.
When you water soil enriched with pumice, most of the water drains away due to the excellent drainage ability of the pumice amended soil. The water that is absorbed by the pumice particles' surface slowly seeps back into the soil over time. This is much better for the general health of succulent plants.
Pumice is a type of porous volcanic rock, and it is also the source of several precious trace elements. Depending on where it is mined from, each pumice has a different type and composition of these nutrients.
It is a great additive for cactus soil and other types of household soils because it may contain over 70 different types of trace minerals in total.
A top-notch component for soil amendment is pumice stone. It keeps the water from turning the soil murky and into the mud. This is a crucial characteristic because it stops the soil from supporting rot-causing fungi.
Pumice makes your potting mix extremely durable, which is its best quality. Being a mineral, it doesn't decompose. It also doesn't get root rot, which is a huge plus point when mixing it with succulent soil.
Due to their durability, their high cost is a sensible one-time investment. It might cost more, but it will last for a very long time.
Try topping off your soil with pumice if you like to keep ornamental plants. First, cover the soil with pumice and pour crushed glass or marbles. These marbles will have true colors and a very appealing appearance thanks to pumice.
Given its slightly larger size and weight, pumice can be regarded as one of the best soil amendments. It usually comes packaged as particles one-third to one-eighth inches in diameter. In contrast to other amendments, these are sufficiently heavy and cannot be washed away by wind or water.
Compared to the majority of other commonly used soil additives, pumice is a much better additive. An overview of a few of these is provided below.
Akadama is a naturally occurring mineral that resembles pumice and is used to amend soil. Compared to pumice, it is softer and more granular. It is also lesser-known, more expensive, and harder to buy comparatively. Pumice is stable and does not disintegrate when compared to the properties of these other two minerals.
Akadama, on the other hand, gradually disintegrates into smaller pieces. This increases their water retention capabilities. It also implies that it completely deteriorates in two to four years, turning into a soggy mass that needs to be replaced.
The name LECA, or lightweight expanded clay aggregate, is essentially an acronym. It comes in hard clay balls that expand when soaked in water. Similar to peat moss, it serves as a growth medium. Nutrients are not present in it.
The clay is being made more pliable as its main goal. Pumice can't compare to its superior capacity to absorb some water and gradually release it. It is also better at preventing rot and pest infestations.
The soil in the plant's pot needs to have pumice added to it. Leca does not need soil to be potted, so you can omit the soil entirely and use Leca instead.
Another naturally occurring mineral is vermiculite. It is mined chiefly in the United States and Unlike pumice, which is a hard rock, it has a texture that is similar to clay and is found in South Africa.
Pumice has more porosity and, as a result, a better potential for drainage when comparing the properties of these two minerals. But vermiculite is far superior in retaining moisture compared to pumice soil.
They both have distinct horticultural goals. Vermiculite is best suited for tropical plants that need more moisture to grow, whereas orchids and succulents are best developed using pumice as the soil supplement.
Perlite is best for drainage and aeration, and it is also reasonably-priced and comes in three different-sized particles for your convenience. Follow the link to read more.
In the plant world, perlite is used to increase the drainage of soil. Since it is originally a rock and does not integrate with the soil particles, it prevents the soil from getting compacted. As a result, the soil develops numerous porosities. As a result, water can easily drain from such porous soil and out of the drainage hole.
Oxygen is required for the growth of every cell in a plant. While the stems and leaves have it easy to obtain air, the roots often get choked for air in the soil mix.
Perlite fills in these spaces by forming tiny air pockets in the soil. In order to reach the roots of the plant, the air must now travel through a number of passages.
The fact that Perlite is fairly affordable is its best quality. In terms of mining and manufacturing, the United States currently dominates the market. Unlike some other commonly used soil amendments, the perlite manufacturing process is cheaper. Perlite is also widely available almost everywhere, so the story doesn't end here.
There are various particle sizes available in perlite, which is best. The world's foremost experts working in an organization called the Perlite Insitute determine these sizes. Every piece of perlite produced worldwide must fit into one of three sizes.
These are their specifics.
The largest particle size in perlite is coarse. It is, of course, the most porous and has the best drainage capabilities. Don't worry, heavy winds can't blow this away too.
For growing succulents, this particle size works best. Succulents cannot tolerate water retention in the slightest. Their soil requires clumpy substances like coarse Perlite or pieces of bark.
Perlite should be incorporated into the soil of orchids and other epiphytic plants that grow on rocks. In fact, this rock must make up about 50% of their potting medium.
Among coarse and extremely fine perlite, this is the middle ground. With regard to drainage and aeration, it also possesses balanced qualities. Medium grade perlite is best suited for seeds and seedlings.
Mix this perlite with compost in a 50:50 ratio to provide the best growth medium ever when planting seedlings. Perlite can be spread on top of some seeds to prevent them from requiring light to germinate. It keeps the seedlings covered and moist while allowing sufficient light to reach them.
Very small particles of perlite are also produced. The wind or water can easily disperse these tiny particles. This makes them less likely to sink to the bottom of the soil to their advantage. When combined with sphagnum moss or peat moss, this grade of perlite works best for planting stem and root cuttings.
Perlite's increased use in soil amendments for plant growth is another typical explanation. It is more readily available to buy or order compared to pumice, coconut coir, or other additives.
An inorganic rock with a fair amount of stability is perlite. No matter how much time passes, it doesn't disintegrate over time or releases any chemicals into the soil. This makes it a secure, nutrient-rich option to use for your plants. The pH of the soil won't change after perlite is added because it has a pH that is neutral.
When it comes to Vermiculite vs. Perlite, both materials have advantages and disadvantages. While vermiculite has more porosity and water drainage potential, vermiculite is far superior at retaining moisture for longer and making sure the roots aren't parched for water.
Vermiculite has a soft texture and is brown or beige in color, making these two distinct from one another. Perlite is a hard rock that is whitish in color, as we have already discussed.
Although Perlite makes a great gardening tool, it also has some drawbacks. The first is that using it sparingly can lead to the soil getting too porous. This frequently results in the water evaporating too quickly, which causes the plant to eventually become dehydrated.
Perlite is a relatively lightweight material, and its dust has been known to irritate the eyes and the throat. As a result, those with respiratory conditions are particularly vulnerable to exacerbation.
Even though it is marginally more energy-efficient than other soil substrates, it is a non-renewable resource, and there is only a finite supply.
It depends on your objectives. Perlite is the best option if you want more decorative qualities with less weight. Pumice has more advantages than perlite in most categories, which is why we recommend it for bonsais in most instances. Additionally, it's ideal when you need more weight in your pot.
As a summary of all the content we've provided above and to help you make a decision between perlite and pumice, here are the advantages and disadvantages of each one.
Pumice and perlite are great options for bonsais and succulents because of the advantages they both offer. As mentioned, they help with aeration in the soil. Trees require assistance to move through the substrate because their tiny roots are too small to do so. These minerals play a role in making it simpler when the soil is not compacted.
If you're using clay or sandy soil due to the species you're growing, pumice can assist with creating pockets for the roots to grow and breathe. Perlite can assist in preventing the soil from clumping together due to excessive watering, even when using a standard mix. Use either one as the top layer, middle layer, or bottom layer.
As decorations, they both look splendid and appealing above the soil. They also help to slow down the evaporation that would otherwise cause soil to dry out too quickly. They won't help with water drainage within the soil itself, though, if you use them as top-dressings.
You can select the size of pebbles you want for your bonsai due to the widespread grade variations. You should study the differences in size to see which ones are more suitable for your container or bonsai style. Additionally, the grades are crucial in ensuring that they are applied to the appropriate substrate layers.
When you buy bonsai mixes from local or online stores, pay attention to the ingredients. Typically, it will list pumice or perlite as one of the many ingredients. Akadama, fine gravel, compost made from organic materials, and occasionally lava rock are among the additional ingredients. However, it doesn't necessarily follow that it is.
If you're buying a standard soil mix with bark, you may want to add pumice or perlite to the mix based on your decision from this comparison guide. Usually, about 5 – 10% of the total soil volume will suffice, but it depends on the grades and where you're placing it:
To aid with fighting diseases, you can add nutrients and microbes that will keep the soil and roots healthy and strong. Even some of these, like the Stone Pine, have mycorrhizal fungi that are advantageous to certain species. We call this process "supercharging" the soil.
Discover more about this subject as we look at some of the most frequently asked questions and our experts' responses to them.
Yes, you can use Perlite and pumice together as there is technically no harm in combining both of them. But both of them need to be consumed in smaller amounts. Avoid allowing the soil to become overly porous.
Cacti do indeed thrive in Perlite. It even flourishes there. Perlite will improve the drainage of the nutrient-rich soil and its air circulation. Free access to some much-needed oxygen will reach the cactus plant's roots.
Pumice can replace perlite because of its superior soil drainage properties and porosity. However, the fact that it needs more processing and is, therefore, more expensive makes it difficult to compete with perlite in the market.
Not to mention how much lighter and more portable it is. Pumice is more likely than perlite to cause an allergic reaction in people who have asthma or other respiratory conditions.
Yes, pumice is definitely better than perlite in the sense that it is more porous and provides better drainage than perlite. Additionally, it is less carbon-intensive and more environmentally friendly.
Mineral rocks mined and then processed in factories include pumice and perlite. Pumice is more eco-friendly to manufacture and also more porous. Along with increasing aeration, it can hold onto moisture. This makes it the better option in our opinion.
But it is not universally accessible, and the question of where to buy pumice for plants lingers on. It is also pretty expensive.
Perlite is the material to use if you're looking for something more affordable. Additionally offered in three grades, perlite has a variety of uses.