Diatomaceous earth is a fine dust made from the bodies of fossilized prehistoric crustaceans called diatoms.
The cell walls from these organisms are made from silica, which makes each particle abrasive and sharp. The nature of these particles, in turn, can make them tremendously effective as a natural and organic form of pest control.
For example, diatomaceous earth can not only physically damage the exoskeleton of invertebrates crawling over it, but it can also dry out pests from the inside out if swallowed or inhaled.
What Kind of Diatomaceous Earth Should I Use?
There are different kinds of diatomaceous earth (or DE for short), and you want to make sure that you buy the correct type for insect control.
Pool Grade DE is used for swimming pool filtration systems. This isn’t the kind you want because it isn’t safe to consume, so can be dangerous in your garden.
Food Grade DE, in contrast, is safe to eat. That means you can use it in a vegetable garden because it can be consumed after being used on vegetables.
Food Grade diatomaceous earth is a product which is all natural. It is classified under the Federal Insecticide, Fungicide & Rodenticide Act as being safe for gardens and homes.
How to Apply Diatomaceous Earth to Your Garden
There are two different methods to use DE in your garden, the dry or the wet method.
The Dry Method
- To start off, you’ll want to select an empty container with holes in the lid, such as a garden duster. Since diatomaceous earth can harm your respiratory system, you should wear a mask and gloves. This is especially true if you have breathing issues.
- Either in the morning or evening, when the plants have some dew on them, dust the plants. The moisture from the dew will help to hold the powder onto the plants. When wet, the powder isn’t active, but once it dries, then it will start the process of killing pests.
- When the powder is applied to garden beds, it will help to kill insects before they spread further too.
- You need to also place a thick layer of diatomaceous earth around the base of plants. This helps to keep squash bugs, snails and slugs from climbing up the stems. It will help also if you apply the powder on the underside of leaves. Be sure after it rains to re-apply the powder.
The Wet Method
- Dissolve four tablespoons of diatomaceous earth into a 1-gallon jug of water. Screw the lid on tightly and shake the jug until all the powder is dissolved. Then fill a spray bottle or a sprayer with the mixture of diatomaceous earth.
- Put on a mask, gloves and preferably goggles before spraying. You need the gloves because the diatomaceous earth will dry out your skin if contact is made. Spray your plants with the solution until wet but not dripping. Make sure you spray the underside of the plant leaves too for the maximum benefits.
- When the plants have dried, it will look like there’s a powder coating on the leaves of your plants.
A Warning When Using Diatomaceous Earth
Diatomaceous earth doesn’t discriminate between insects which are harmful to your plants and the ones which are beneficial. As a result, try to avoid areas where beneficial insects frequent. If not, you’ll damage your population of ladybugs, bees, butterflies and other insects which do good to your garden.