Diatomaceous Earth

By Vanessa Richins

I wanted to be a marine biologist when I was growing up.

I would visit the tidepools and find the crabs, sea anenomes, limpets and more.

We took trips to a local science center where people could peer at smaller creatures under the microscope.

One kind of tiny ocean dweller is the diatom. These are algae that have developed a hard outer shell. They come in many shapes and sizes and are exquisitely beautiful, as these pictures show. After they die and fossilize, they are ground up into a fine powder called diatomaceous earth.

What does this have to do with urban gardening?

It turns out that many insects can be killed by using diatomaceous earth. The ground outer shell has very jagged, sharp edges that cut the exoskeleton of the insect when it comes into contact. This allows the sun and air into their shell, so they dry out and eventually die.

Since diatomaceous earth is made from natural algae, it’s Read the rest of this entry »