Diatomaceous earth is a very popular substance to use with indoor plants and potted plants in general.
It can be used to amend potting soil as well as to keep soft-bodied insects such as spider mites and pill bugs at bay.
So, let’s take a look at how diatomaceous earth helps in the indoor garden and why you might want to invest in some for your plants and potting soil.
What Is Diatomaceous Earth?
Diatomaceous earth is not, in fact, plain old soil. Instead, it’s a crushed form of sedimentary rock that contains aquatic fossilized “diatoms”.
Thus diatomaceous earth is a white powder with highly absorbent properties. This is what makes it a popular choice for use with indoor plants.
It comes in many different quality grades and while you can eat food grade diatomaceous earth (though we’re not sure that you’d want to most of the time), the diatomaceous earth used for treating pools is toxic when consumed.
So, it’s best to read the packaging before you apply diatomaceous earth to any given plant or your potting soil.
Why Would You Use Diatomaceous Earth Powder On Your Plants?
Diatomaceous earth has two properties that make it super useful when it comes to helping indoor plants.
The first is that it acts as a “desiccant” that is it’s super absorbent (as we’ve already seen) and thus it can dry things out.
And it has sharp edges. So, when your plants attract pests (and they will), diatomaceous earth helps to kill insects with soft bodies such as fungus gnats, mealybugs, aphids, etc. and it does so without using poisonous or toxic substances.
The sharp microscopic edges of the diatomaceous earth cut the insect’s exoskeleton. Then the desiccant property draws moisture out of the insect pests killing them.
This desiccant property also helps when you amend the soil mix for potted plants because it helps the soil stay damp without becoming flooded (which will kill most potted plants).
How Much Should You Use When You Apply Diatomaceous Earth?
How much diatomaceous earth should you use? When using diatomaceous earth in potting soil, you should be looking to keep the mix of diatomaceous earth at less than 20% of the overall soil structure.
The organic sedimentary rock powder will provide that diatomaceous earth benefit up to a point but if you use too much? You will see the diatomaceous earth kill plants too.
If your potting soil has gone bad, make sure to bear in mind any previous amounts of diatomaceous earth that you’ve added to it – a little diatomaceous earth is great but too much is never a good thing.
When you want to use diatomaceous earth as a pesticide? Then you need to show some care when applying diatomaceous earth to the plant. It’s best to lightly dust the powder over the plants ideally after they’ve been watered, this allows for spreading diatomaceous earth evenly but without overwhelming the plant.
You can also make a dilute solution and spray plants with it, though it’s best not to use neem oil at the same time.
Safety Precautions You Must Follow Even When Using Food Grade Diatomaceous Earth
Diatomaceous earth is unlikely to poison you but as it is a very fine natural powder (like baby powder or the dust on cat litter) it can seriously irritate your airways, lungs, and nose.
It’s best to apply it to house plants while you’re using a dust mask, a dust spreader, long sleeves, and long pants too.
We’d also recommend that you keep kids and pets away while you work. The idea is to get rid of unwanted garden pests rather than those you love.
How To Use Diatomaceous Earth To Amend Your Soil Mix
Indoor plant lovers don’t need to work very hard to amend their soil mix with diatomaceous earth.
Just mix 20% earth – 80% potting soil by weight, thoroughly before planting anything in the soil.
How To Use Diatomaceous Earth To Kill Insects And For Pest Control?
Add a light dusting to the soil’s surface and the surface of the plants. Don’t use neem oil at the same time (neem is great but it’s best used on a different day).
If you find that your plants are struggling with a natural pesticide regime – you might consider investing in pest-resistant plants too.
Using diatomaceous earth is easy and it’s a natural and safe way to combat a pest infestation or to ensure that your plant medium is giving your plant roots enough water.
Just make sure to use it in the right quantities and use the right safety gear and you’ll be fine and your plants will be happier for the use of diatomaceous earth!