If you are looking to control ants in the kitchen, cockroaches in a commercial establishment, fleas or bed bugs in a bed or sofa, crawling pests in a horticultural crop, or you need an effective absorbent for oil or liquid spills in a workshop, without resorting to pyrethroids or neonicotinoids that leave chemical residues, natural diatomite is one of the few products that performs this physical insecticidal function without generating resistance in the pest. This guide explains how to identify the target pest, apply the product dry or in a wet suspension, and protect your health during application of the respirable dust, which is the only critical precaution for the product.
Diatomite is microscopic algae fossilized millions of years ago — a biogenic silica skeleton. Its insecticidal mechanism is physical, not chemical: the microscopic edges of the silica pierce the waxy cuticle of insects on contact and dehydrate them within hours. The consequence is that pests do not develop resistance (there is no active compound to mutate against) and that the product keeps working indefinitely as long as it is applied correctly.
Product specifications
GARDESE diatomite is offered in a single standard format: natural uncalcined product, micronized, in a 20 kg bag. It is very important to respect the natural uncalcined version for insecticidal and agricultural use; calcined diatomite (crystalline silica) is much more dangerous when inhaled and is NOT used in these contexts. The following table contains the complete technical specifications of the only available variant:
| Specification | Value |
|---|---|
| SKU | 571311 |
| Material | Biogenic silica (fossilized algae) |
| Treatment | Natural (uncalcined) |
| Particle size | Micronized (fine powder) |
| Format | 20 kg bag (44 lb) |
| Color | White to light beige |
| Insecticidal mechanism | Physical (dehydration by abrasion of the cuticle) |
| Organic compatibility | Allowed under organic farming standards |
| Absorbent capacity | High (several times its weight in liquids) |
| Shelf life | Indefinite if kept dry |
There are two forms of diatomite on the market and they are NOT interchangeable: the natural uncalcined form (this product) is amorphous silica, safe for agricultural and insecticidal use with the standard precaution for respirable dust. The calcined form is heated to high temperature and partially transformed into crystalline silica, much more dangerous when inhaled and classified as carcinogenic by the WHO. The calcined form is used exclusively as an industrial filter medium (NOT in agriculture, NOT against insects in the home). Always verify that the product you buy is natural uncalcined for the uses described in this guide.
The sister guides for zeolite, expanded perlite, expanded vermiculite and pumice cover the other mineral amendments in the catalog and help decide which is best for each case according to the function required.
Step by step on how to use it
The following procedure covers the main uses: pest control in the home and agriculture, silicon supply for crops, and spill absorption. The safety measures for respirable dust are critical and are detailed in step 2.
Identify the target pest or use
Diatomite acts against crawling pests (ants, cockroaches, fleas, bed bugs, ticks, snails) and flying pests when they land on the treated surface (mites, thrips, aphids). It is less effective against caterpillars, large larvae and pests that do not come into direct contact with the powder. For agricultural use as a silicon supply, dose 100-300 g per m² of crop depending on the species and need. For absorbing spills in a workshop or garage, use enough to cover and fully absorb the liquid.
Personal protective equipment (PPE)
Diatomite dust is respirable and, although chemically inert, it irritates the airways by simple mechanical action if inhaled continuously. BEFORE applying, use a particle filter mask rated FFP2 or N95 (common surgical masks are NOT sufficient), protective goggles, gloves and long-sleeved clothing. If working indoors, ventilate the area well during and after application. Keep children and pets away from the area during application and until the dust settles (generally 30 minutes to 1 hour). Once settled, diatomite is safe.
Dry application for pest control
Apply the fine diatomite powder directly with a duster, a modified salt shaker or a brush onto the pests' travel zones: room perimeters, under appliances, wall cracks, corners, around pipes and damp areas, pet beds, and cavities where ants or cockroaches nest. The layer should be thin and visible (1-2 mm thick); more powder is not more effective and only increases waste. Diatomite acts by contact: pests that cross it or land on it absorb powder into their cuticle and die from dehydration within hours or a few days.
Wet application for outdoor crops
For outdoor horticultural crops where wind can disperse the dry powder before it does its job, prepare a suspension with water: mix 50-100 g of diatomite per liter of water with a natural surfactant (a drop of potassium soap) to improve adhesion. Spray over the foliage and the soil of the crop with a backpack sprayer. When the water evaporates, a thin film of diatomite remains that performs the insecticidal function without risk of inhalation for the applicator or dispersion by wind. Reapply after heavy rains that wash off the film.
For pest control in outdoor crops with a drip or sprinkler irrigation system, combine wet diatomite application with irrigation directed at the root zone instead of the foliage. This keeps the diatomite on the foliage protected from being washed off by irrigation, multiplying its effect day by day without constant reapplication. The technique is standard in organic production of vegetables with sucking pests (aphids, thrips) in crops such as tomato, pepper, lettuce and brassicas.
Reapplication and maintenance of control
Diatomite loses its effect when it gets wet: water does not destroy it, but the wet suspension does not have the mechanical abrasiveness of the dry powder against the cuticle. Indoors, reapply every 2-4 weeks in areas with occasional humidity or if cleaning with water may have removed the powder. In outdoor crops, reapply after each heavy rain or sprinkler irrigation that may have washed the foliage. For pests with short generation cycles (fleas, bed bugs), consider reapplications every 7-10 days for 2-3 cycles to ensure interception of adults that emerge after the first treatment.
Do not confuse NATURAL uncalcined diatomite (this product) with CALCINED diatomite. The calcined form is heated to high temperature and forms crystalline silica (cristobalite, tridymite), classified as carcinogenic by the WHO for chronic inhalation. The calcined form is used exclusively as an industrial filter medium in treatment plants. If the label of the product you are considering says "calcined" or "food grade" without the word "natural", do NOT use it for pest control in the home or in agriculture. GARDESE micronized natural diatomite is the correct version for the uses described in this guide.
Complementary products
To complement diatomite in integrated pest control, organic agriculture and industrial absorption, the following products cover the most common adjacent needs:
Zeolite is a natural complement in stables, pet beds and damp areas: diatomite controls pests while zeolite absorbs ammonia and reduces odors; the combination covers integrated environmental control. Coconut fiber substrate is the ideal base to mix with diatomite in horticultural crops with recurring problems of crawling soil pests. Weed control net reduces the habitat of crawling pests by eliminating the weeds where they hide. Expanded perlite in professional mixes is complemented with a small fraction of diatomite to supply silicon and prevent substrate fungi.
Maintenance and care
Diatomite applied for pest control requires periodic reapplications depending on the environment: in dry environments, one application lasts weeks or months without losing its effect; in humid environments or with frequent cleaning with water, the reapplication frequency rises to 2-4 weeks. For agricultural use, observe the effect after 7-10 days from the first application: if pest pressure has decreased but not been eliminated, reapply after watering and letting it dry.
For storage of the unopened bag, keep the bag in a DRY, covered place. Ambient humidity does not destroy diatomite but it forms clumps that make application with a duster or sprayer difficult. If the powder gets slightly damp, dry it out by spreading it on a tray in the sun or in a low oven (60°C) for one hour before applying. For partially used bags, close with wide adhesive tape. Diatomite does not expire and can be used for years without loss of efficacy as long as it is kept dry.
Frequently asked questions (FAQ)
Is diatomite safe for pets and children?
Natural uncalcined diatomite is physically and chemically safe for mammals in contact with the skin and through small ingestion (it is not toxic). The only critical risk is inhalation of the dust during application: the respirable dust irritates the airways. Keep children and pets away during application and until the dust settles (30-60 minutes). Once settled on a surface, diatomite is completely safe. For use in pet beds or treatment against fleas on dogs and cats, use only the NATURAL uncalcined version and apply with the pet out of the area, letting it back in after the dust has settled.
Can I use diatomite against cockroaches and ants in the kitchen?
Yes, it is one of the most effective uses of the product. Apply in thin lines behind appliances, under the sink, in cracks between furniture and walls, in drawer corners (under decorative paper) and in the pests' travel zones. Keep food preparation surfaces free of powder — diatomite is not toxic if accidentally ingested, but it creates a gritty sensation and is not pleasant. Pests that pass through the treated areas absorb powder into their cuticle and die from dehydration within hours or a few days. Efficacy is greater in dry environments.
When will I notice the effect against a pest?
For individual pests that come into contact with diatomite, the effect takes hours to a few days: dehydration by abrasion of the cuticle is not instantaneous like a chemical pyrethroid, but it is inevitable and with no possibility of resistance. For established infestations, expect 1-2 weeks to evaluate a significant reduction in the number of visible individuals. If the pest persists after 2-3 reapplications, evaluate whether it is entering from an untreated external source or whether it requires combination with another strategy (baits for ants, elimination of the food and water source for cockroaches, washing fabrics at high temperature for bed bugs).
