Diatomaceous Earth for Gardens
Diatomaceous earth (DE) can be found in gardens around the world. Today, I’m going to explain why using diatomaceous earth in your garden might be the best decision your green thumb will ever make.
Food Grade Diatomaceous Earth
Diatomaceous earth is a unique type of soil derived from fossilized water plants. It’s a naturally-occurring mineral compound that comes from the remains of algae-like plants called diatoms.
Diatoms are some of the oldest plants in the world. They date back millions of years. As these plants decayed over the years, they left behind chalky deposits called diatomite. To create diatomaceous earth, manufacturers harvest diatomite and fossilized diatoms in order to make a substance that looks and feels like talcum powder.
Chemically speaking, diatomaceous earth contains all of the following minerals, including 3% magnesium, 5% sodium, 2% iron, 19% calcium, and 33% silicon (and several other trace minerals).
What to Know Before Buying Diatomaceous Earth for your Garden
When you use diatomaceous earth in your garden, it acts as a natural, mineral-based pesticide. However, since diatomaceous earth has many different uses, it’s important to remember to buy food-grade diatomaceous earth (as opposed to filter-grade).
Non-food-grade diatomaceous earth can be found in swimming pools and other environments, where stronger chemicals are used (the manufacturing process used to make swimming pool-grade diatomaceous earth changes the chemical profile to contain a higher amount of free silica).
It’s also important to remember to wear a dust mask when applying diatomaceous earth to your garden. You don’t want to inhale the dust (even when you’re using the food-grade stuff). When you breathe in diatomaceous earth, the particles can lodge themselves in the mucous membranes of your nose and mouth.
However, once you’ve applied the diatomaceous earth and it’s settled into the ground, it will not pose a problem for you or pets. It will also not affect your food (except by keeping pests away, of course!)
Benefits of Using Diatomaceous Earth in your Garden
Diatomaceous earth is typically used as a natural pesticide in gardens. When used as a pesticide or insecticide, diatomaceous earth has proven effective at getting rid of all of the following insects, including:
— Adult Flea Beetles
— Larvae, maggots, grubs, and similar creatures
Why is diatomaceous earth a pesticide? Many people are surprised to learn that diatomaceous earth doesn’t actually kill insects using toxic chemicals (like a traditional pesticide). Instead, the tiny particles in diatomaceous earth have microscopic sharp edges. When insects are exposed to these sharp edges, they get eviscerated.
The diatomaceous earth cuts through the insect’s protective exoskeleton. Then the particles dry out the insect, which eventually causes the insect to die.
When used as a pesticide, some people apply diatomaceous earth as either a form of particle dust or in wet spray form.
Diatomaceous earth’s biggest advantage is that it’s 100% natural. Its second biggest advantage, however is that insects cannot build up a resistance to diatomaceous earth. When using modern, chemical-based insecticides, bugs can often become immune over the years, which eventually leaves you with no effective way to kill the pests. Diatomaceous earth doesn’t have that problem: it’s been effectively killing insects for centuries.
One final benefit of diatomaceous earth is that it doesn’t harm most beneficial microorganisms in the soil. Worms, for example, are not affected by the microscopic edges in diatomaceous earth particles.
Even though diatomaceous earth contains microscopic sharp edges, it’s not harmful to human skin (just don’t breathe it in). You can safely rub it between your fingers.
How to Use Diatomaceous Earth in your Garden
Using diatomaceous earth in your garden is pretty straightforward. Whenever you buy diatomaceous earth, you’ll see detailed instructions on the package explaining exactly how to use it.
Since diatomaceous earth formulas can vary slightly between manufacturers, it’s always important to follow the instructions on your diatomaceous earth packaging. Just because you’ve used diatomaceous earth before doesn’t mean you automatically know how to apply all types of diatomaceous earth.
Typically when used in a garden, you apply diatomaceous earth as a dust using a dust applicator. As mentioned above, wear a dust mask during the application process and keep pets and children away from your garden until the dust has settled.
Be sure to coat the topside and underside of all plants with the dust for maximum coverage. You’ll also need to reapply diatomaceous earth if it rains immediately after you apply it.
Many gardening experts actually recommend applying diatomaceous earth when your plants are a little bit wet, however, as the moisture helps the dust stick to the foliage. Try applying after a morning dew or light rain.
If you’re having trouble applying the diatomaceous earth powder, consider using a parmesan cheese container as a shaker. These containers have the perfect-sized holes and can easily be re-sealed.
Some people avoid the dust problem entirely by applying diatomaceous earth in wetted form (although you should still wear a dust mask).
Use the following mix ratio to apply diatomaceous earth in a spray bottle: one cup of diatomaceous earth per half gallon of water (or two cups per gallon of water for larger gardens).
You’ll need to stir your wet diatomaceous earth often to ensure it’s well mixed with the water. You can apply the mix in a spray bottle, although some people prefer applying it like a paint with a small paintbrush.
When applying wetted diatomaceous earth, you should spray the plants until they are wet, but they should not be dripping.
As plants dry, the water will help the powder stick to the plants, giving them a thin dusty coating.
If you live in a windy environment, then the wetted spray bottle method is the best way to apply diatomaceous earth.
In addition to dust masks, some gardeners recommend wearing goggles when applying diatomaceous earth.
Whether applying diatomaceous earth using the wet or dry method, you should avoid leaving heavy layers of diatomaceous earth on the leaves of vegetable plants. Excessive amounts of powder can prevent sunlight from reaching the leaves, which interferes with photosynthesis and inhibits growth. Remember: you only need a thin layer.