Diatomaceous earth is a mineral powder that can help you get rid of fleas, cockroaches, ants, and dust mites. You can apply it in wet or dry form—applying it in wet form allows it to cling to a surface easier, especially in the wind. Whether you're applying it as a dry powder or mixing it with water to spray it on your yard, avoid breathing it in and only apply it to spots that need protecting.
Use diatomaceous earth on plants that truly need it. Instead of spreading the powder all over your yard, only use it on plants that are being eaten or really need the protection. This will help protect beneficial insects that you might have in your yard, such as bees.
• Apply it close to the ground, and avoid spreading it over flowers that are in bloom so that you don’t harm bees.
Diatoms are unicellular algae, one of the two major classes of the phytoplankton that constitute the bottom of the food chain in oceans and freshwater. Diatomaceous earth is a soft, siliceous sedimentary rock containing the fossilized skeletal remains of diatoms. It has been used as a bug killer: it is hypothesized that the sharp particles physically cut up the insects and also damage their waxy protective layer, causing dehydration. It is also used as an abrasive, a filter, an anticaking agent, and in various other industrial and agricultural applications. It contains silica, mainly in the form of amorphous silicon dioxide but with some crystalline silica. Silica is dangerous when inhaled, causing lung disease in workers exposed to silica dust. Silicosis is the most common occupational disease worldwide.
Those are the indisputable facts. So far, so good. Now for the unsupported claims. Diatomaceous earth is being sold as a dietary supplement and is being promoted as “one of the cheapest and most versatile health products on the market.” One of the red flags for quack remedies is the claim that the remedy works for a long list of disparate ailments. Another is that the claims are supported only by testimonials, not by scientific studies. Another is the claim that it “detoxifies.” And most of those who claim it works just happen to have their own brand that they want to sell you. Diatomaceous earth fits the bill, on all counts. But just because it walks like a duck doesn’t mean we can summarily dismiss it. To be fair, we must examine the claims and the evidence.