Ways To Use Diatomaceous Earth Around Your Home And Garden

What's common to water filters, cosmetics, medicines, livestock feed, paints, and pesticides? They all often include diatomaceous earth (DE). If you've been following the discussions about environmental conservation, you'd have probably guessed that this substance is made from diatoms (just segment the name). Responsible for creating 20% to 30% of the earth's breathable air (per Diatoms of North America), diatoms are aquatic algae with silica-based cell membranes. When these organisms die and calcify, their deposits are mined and processed to create chalky, gray diatomaceous earth, or diatomite.

While its origin might feel a little dark and murky, it isn't toxic and falls on the US Food and Drug Administration's "Generally Recognized as Safe" (GRAS) list. As such, it's been approved as an agricultural anti-caking agent and insecticide. Pest control aside, DE holds utility across diverse applications, from improving the soil's nutrient profile and water retention to removing tough, greasy stains. However, this doesn't dispense with the need to take precautionary measures, as exposure to some dust formulations can cause skin, eyes, and nasal irritation. So, ensure you wear gloves, eye protection, and a respirator, and be fully clothed when using the product. This is especially important for products high in crystalline silicon dioxide—another natural form of diatomite—because they're smaller in size and have a higher risk of building up in the respiratory tract. So, stick to food-grade diatomaceous earth, as it contains between 0.5% and 2% crystalline silica and is relatively safer.

The bugs won't magically stop munching on your houseplants just because they're indoors. They will risk it if there's potential for food and shelter. While houseplants are less likely to have aphids sucking them dry, flies, fungal gnats, and mites aren't so kind. Luckily, diatomaceous earth easily takes care of these common household pests without synthetic chemicals. Simply spread it over the potting medium when it feels dry and wait for the pesky invaders to drop dead within five to seven days of application. Sprinkle a little extra around the pot to block crawling insects from reaching your plant. Another added advantage? It purges the larvae wriggling in the compost mix at your plant's base.

Avoid using the dust if the plant is due for a watering, as the powder hardens upon becoming wet, compromising its abrading and dehydrating effect. Diatomite works by leeching off the lipids from the bugs' exoskeletons, which happens no more if it's busy slurping the water in the soil. Besides, the tiny crystals' razor-sharp edges lose their sheen in solid form, making them less effective at cutting the pests' bodies. That being said, ensure DE doesn't get on the foliage, lest it dry out the leaves if left on for too long. Although higher dosages show better results, they can be harmful indoors, so look at the product's toxicity labels before using it. Otherwise, supplement it with natural products like neem oil.

While most gardeners wax eloquent about nitrogen, potassium, phosphorus, and other micronutrients, functional nutrients like silicon are often overlooked—for good reason. They're amply available in most soils. There's a catch, though, as not all silicon forms are water-soluble, making it harder for the plants to absorb them. Since diatomaceous earth is made of silicon dioxide, using it to amend the soil can bear fruit. To make it work, simply top up the substrate with a few inches of DE. Another alternative is to mix it in with compost before laying it down on the soil.

As a soil conditioner, DE can improve the nutritional profile of the soil, raising plant productivity. Not only silica, but it also adds trace elements like magnesium, calcium, and iron that play a critical role in furthering cell growth and chlorophyll production. It may even raise disease resistance for some shrubs. For instance, feeding cucumbers, pumpkins, and squash with silicon-based fertilizers has reduced their susceptibility to powdery mildew. Silicon is also known to advance the ability to bear droughts and metal toxicity. Applying DE to the substrate minimizes fertilizer and soil leaching, boosting plant health, as also found by Southern Cross University's research. This, in turn, enhances the plant's ability to withstand environmental stressors while optimizing fertilizer application. Even better is the data that it isn't toxic to aquatic animals, so its washing down (due to rainfall or otherwise) shouldn't be concerning, in contrast to chemical fertilizers.

Unlike pesticides that accumulate in and contaminate the soil and groundwater with time, diatomaceous earth is a natural, inexpensive way to repel major garden pests like millipedes, mites, aphids, earwigs, slugs, and snails. The default method is to evenly spread the inert dust all over the plant's stems and foliage using a flour sifter or a mesh strainer, in addition to creating circular barriers around their base to restrict the crawlies. Ensure the product is sprinkled thinly, or the insects will make a beeline for an alternate route. While this works great in smaller gardens, it can get too time- and labor-intensive in bigger landscapes. Applying it to the leaf's undersides can be cumbersome—even more so if it's windy. In such cases, liberally spritz diluted diatomite by mixing 1 to 2 tablespoons for every quart of water, as it attaches easily to the surface and works like a charm after it dries. Reapply when the leaves lose their white sheen or are exposed to dew and rain.

DE's prowess lies in discomforting the vermin walking through it, as its sharp edges cut through their exoskeletons while parching them dry of oils and water. However, it's only possible on soft bodies, as with slugs, but it doesn't work on hard-shelled Japanese beetles. You may want to rethink using diatomaceous earth because it's an indiscriminate killer, so don't use it around flowering plants to not harm the pollinators and beneficial insects.