601 Winspear Road Elma, NY 14059
Phone & Fax 716-651-9289 or 800-443-6693


Diatomite (Diatomaceous Earth) is a sedimentary rock primarily composed of the fossilized remains of unicellular fresh water plants known as Diatoms. Over the millennia the diatoms have been compressed to create one of the most effective growing mediums available. Diatomite consists of approximately 90% silicon dioxide, with the remainder of its contents being elemental minerals, which are essential for plant growth. All of these unique factors make Diatomite the premium horticultural grade medium for all growing applications.

All Diatomite is not created equal. You may be familiar with diatomaceous earth that is used in filters and as an insect and slug repellant. These types of products are not suitable for horticulture because the diatoms are of salt-water origin, leaving them with a high salinity level that is not suitable for plants.

Our diatomite is Maidenwell Diatomite and comes from an Australian mine that has a fresh water origin. Maidenwell ™ is natural, non-toxic, with minimal contaminants and salts that make most other sources unsuitable for horticulture.


Diatomite is High in Silica, Absorbent, Porous, Long Lasting, Environmentally Friendly, pH Neutral, Sterilized, Natural and Reusable, all factors necessary for health plants, while still being cost effective for the grower.


High Silica Content Silica is essential for healthy plants and roots. While Diatomite is approximately 85% insoluble Silica, it contains a small but significant portion that is SOLUBLE SILICA. Silica is essential for healthy plants and roots. Your plants will receive from Diatomite a slow release of silica resulting in healthier, more robust plants. Plant available silica has been shown in studies to stimulate SYSTEMIC ACQUIRED RESISTANCE (SRA) in plants which increases their resistance to disease.
Absorbency & Porosity Diatomite is naturally very porous, and can hold 150% of its weight in water. The Silica Content, natural Absorbency, and Porous qualities result in a slow release of water and nutrients to your plants, contributing to higher yields and less watering.
Capillary Action & Lateral Movement The porosity of the Diatomite contributes to its ability to draw water, while moving water and nutrients laterally throughout the medium, making Diatomite ideal for Hydroponics!
Air Penetration Diatomite is multifaceted and varies in size. Because each rock is unique in shape it does not compact while in the pot. This leaves pockets, allowing air to penetrate and circulate to the root zone.
Sterilized, Non-Toxic, pH Neutral When Diatomite is mined it is heat treated to over 600 degrees Celsius, making it completely sterile and safe for all of your planting needs. Whether you are using 100% diatomite or you are adding it to a mix of your soil it will not contribute to changes in pH.
Environmentally Friendly Diatomite is a fossil, making it natural, safe and an Environmentally conscience alternative. We have visited the mine in Australia, and we are confident that the practices used to mine our product are safe and in accordance with Australian environmental guidelines.
Long Lasting, Natural Diatomite is inert and will not break down or decompose like other growing mediums. It is Natural and completely reusable. When dry, diatomite is extremely lightweight, making it ideal for plant shipping purposes. Because it is Reusable and Long Lasting it is economical and cost effective for long term use.
& Reusable

We have four sizes available for all of your growing needs

Fine (#1) 1/32 to 3/16 inch 0.5mm to 2mm
Small (#2) 1/16 to 1/4 inch 2mm to 7mm
Medium (#3) 1/4 to 5/8 inch 7mm to 15 mm
Large (#4) 5/8 to 1 inch 15mm to 25 mm


DiatomiteUSA is family owned and operated business based in a suburb of Buffalo, New York on the shores of Lake Erie. Our goal is to provide all growers, a superior quality broyeur vegetaux product , while maintaining excellent service and competitive pricing to all markets in the USA and Canada. While our online sales are geared to smaller quantities, we are capable of meeting and exceeding your quantity and service requirements. Wholesale prices are available upon request. Give us a call, fax, email, or drop by the farm, and we will be more than happy to discuss your needs.

Thank you for taking a look at our website, and we look forward to hearing from you.

Good Growing,

Joe & Michael DiDomenico
(Father & Son)

Tips for Orchid Mix use:

  1. Soak the diatomite in water for about an hour to allow it to absorb water before you use it. Add 1/4 teaspoon of Superthrive or KLN to the solution if available.
  2. Diatomite can be utilized in a variety of ways. For example: a) It can be substituted for the bark in a mix b) It can be added as an additional component of your mix. c) Many growers are using it mixed with perlite and peat. H & R Nurseries, Inc. of Hawaii is using the following mix: 40% Diatomite 50% Perlite 10% Peat Moss

Orchid Potting Mixes

As most orchid enthusiasts know- growing conditions -be it on the windowsill, under various artificial light systems, or in a greenhouse will vary widely for individual to individual. The same is also true for light levels, temperatures, humidity, fertilizing, and watering schedules used in our diverse growing conditions. As a result, successful growers develop mixes that fit their particular conditions, preferences, and procedures. The following mixes are suggested as a starting point. We strongly encourage you to make up a few variations that you think will work for you and experiment with them to see what works best. We suggest that when using Diatomite in your mix- think larger, looser, less watering, and less frequent repotting!

Small mix
for your finer rooted plants and seedlings:

Small bark or Coconut Husk Chips (CHC)
n.1 or n.2 Perlite
n.1 or n.2 Diatomite (2-7mm)
Small Charcoal

For Masdevallias & Plureothallids
Fine tree fern
n.1 or n.2 Diatomite
n.1 or n.2 Perlite

Medium mix
This is the ‘starting point’ for most plants in 31/2” pots and larger
Including paphs and phrags

Medium bark or CHC
n.3 or n.4 Perlite
n.3 Diatomite (7-15mm)
Medium charcoal+Peat Moss (optional)

We grow our phrags in straight n.3 diatomite
in water trays or on our flow table.

Large mix
for standard cattleyas, vandas, etc.

Large bark or CHC
n.4 Perlite
n.3 and n.4 Diatomite (7-15mm, 15-25mm)
Large Charcoal

We grow many of our cattleyas, phals and
vandas in straight n.3 Diatomite.

Note: We want to hear about your particular growing conditions and the mixes that work for you with your various plants. Drop us an email and let us know what is working for you!


Due to the variability of hydroponics systems and growing conditions, some trial and error will have to be used to determine your ideal nutrient levels and watering schedule. We suggest that you reduce your watering frequency and nutrient level because of the liquid retention of Diatomite.

This is an ideal medium of hydroponics! There are several reasons why--

Absorbent it can absorb up to 150% of its own weight in water.
Capillary Action & Lateral Movement it has the ability to draw water up from the bottom and provide effective lateral movement of water and nutrient.
Air Penetration Because it is multi-faceted and does not agglomerate, the microscopic porous structure of the granules provide aeration and effective thermal insulation to the plants root zone.

Hydroponics Uses

As there are numerous systems in use, each of the sizes has its use, with #2- Small (2mm to 7mm-3/16 to 9/16 inch) and #3- Medium (7mm to 15mm-9/16 to 5/8 inch) as the most often used for this application.

We suggest that you thoroughly saturate the diatomite for about an hour when first using it (try not to rinse, as the fines will help provide plant available silica.)

As various trials continue, we will add specific recommendations.

Sterilization for Re-Use

After use, we suggest that you thoroughly wash the Diatomite and then soak it in an algaecide for 24 hours. Rinse again thoroughly before reusing it in your system. Diatomite can be reused indefinitely in your systems. Dilute Chlorox (1 teaspoon / gallon) can be used. We recommend using ‘Physan 20 ™’- produced by Maril Products Inc., and ‘Consan Triple Action 20™’- produced by Parkway Research Corp. Please follow all manufacturers recommendations.


In the garden

The easiest way to begin is to add diatomite to the mix you are currently using for your houseplants. Fine or Medium can be added to your standard mix (start with a 1/4 or 1/3 portion and adjust as you go on to suit your growing conditions).

African Violets start with standard African Violet mix and add 1/4 to 1/3 portion of #1 to mix, or If a coarser mix is desired, use #2 instead. As growing conditions are variable, you will need to experiment to get a mix that is ideal for you.

Organic Gardening

As a fossil material and 100% natural, Diatomite is a product suitable for all organic gardening applications.

It can be used in various ways in all types of gardens:

Insect & Pest Control

Diatomite is more than a growing medium. Not only does it contribute to healthy, more robust plants, it is also a natural alternative for insect and pest control. Diatomite USA’s Pest Control Powder is the same product as our Diatomite, only that it has been pulverized into a powder form. Your plants will not only benefit from being protected from pests, but the silica in the diatomite will also be made available to your plants.

Diatomaceous earth (DE) is composed of microscopic sharp edges that cut into, and penetrate the exoskeleton of an insect. The tiny cuts cause the insect to lose moisture, resulting in the insects demise from dehydration within hours of coming into contact with the Pest Control Powder. Insects that eat the dust will experience the same end.

Just like our Diatomite, our Pest Control Powder is odorless, nontoxic, and a completely organic substance. It does not contain any chemical additives, making it safe for people, plants, pets, and animals.

If your garden or pet is adversely effected by ants, roaches, box elder bugs, crickets, silverfish, caterpillars, grasshoppers, spiders, carpet beetles, fleas, ticks, slugs, snails and earwigs, and you are looking for a safe non-chemical alternative, please see our shopping cart where Pest Control Powder is now available in 3 and 10 pound sizes.

Using Pest Control Powder in the Garden

When applying Diatomite USA’s Pest Control Powder simply lightly dust the affected are of the plant as well as its base. Reapply the powder after heavy rains.

Slug and Snail Control

Slugs and snails avoid moving across DE because of the microscopic sharp edges that cut into them. We suggest using our #1 size for the control of slugs and snails. Spread the diatomite around base of the plant making sure to create an area that covers the plants entire circumference. DiatomiteUSA size #1 comes in 15 pound and 40 pound bag amounts, and is available through our shopping cart.

Household Pets-Fleas and Ticks

Fleas and ticks can spread quickly, especially in a kennel environment. DiatomiteUSA Pest Control Powder is a very safe and effective alternative to chemicals. Apply the Pest Control Powder by dusting pet beds, carpets, cages, resting areas, or any other area these pests are found. It can safely be applied directly onto your pet by rubbing it thoroughly onto your cat or dogs coat. It is completely non-toxic and safe for your pet to ingest, saving your pet from being exposed to possibly harmful chemicals. Our Pest Control Powder comes in 3 and 10 pounds sizes and is available through our shopping cart.

Our only recommendation in using our Pest Control Powder is that you take care to avoid inhaling the dust. For your own safety, we suggest using a dust mask during application. If applying directly to your pets, we also suggest avoiding their mouth and eye area while working it into their fur.