Diatomaceous earth (DE) is a naturally occurring sedimentary rock that is made up of the fossilized remains of diatoms. It is often used in gardening and agriculture as a natural pest control remedy due to its abrasive texture that can be harmful to insects. However, the question of whether diatomaceous earth is safe for plants is a valid concern for many gardeners.
What is Diatomaceous Earth?
Diatomaceous earth (DE) is composed of the fossilized remains of diatoms, which are a type of algae that lived millions of years ago. When these organisms died, their shells settled at the bottom of bodies of water and formed sedimentary rock now known as diatomaceous earth.
DE is made up of about 90% silica, which makes it extremely porous and abrasive. These properties make it an effective pest control remedy in both gardening and agriculture. It is often used to control pests like beetles, slugs, snails, and aphids by dehydrating and killing them.
Is Diatomaceous Earth Safe for Plants?
The short answer is yes, DE is safe for plants. It is a natural and non-toxic substance that can be used to control pests without harming the environment or plants. However, there are a few things to consider when using DE in your garden.
1. DE Can Dry Out Plants
DE works by dehydrating insects, and it can also have the same effect on plants if used excessively. When sprayed directly on plants, DE can dry them out and cause damage. It is important to use DE sparingly and avoid spraying it directly onto plants. Instead, sprinkle it around the base of plants or use it in a dust form.
2. DE Can Alter Soil pH
DE has a high pH, which means that it can raise the pH level of your soil if used excessively. This can be detrimental to some plants that prefer a more acidic soil. It is important to test the pH level of your soil before using DE and to use it sparingly to avoid altering the pH level significantly.
3. DE Can be Harmful to Beneficial Insects
While DE is an effective pest control remedy, it can also harm beneficial insects like bees, ladybugs, and earthworms. These insects play an important role in the ecosystem and in the health of your garden. It is important to use DE selectively and avoid using it near flowering plants or where beneficial insects are active.
How to Use Diatomaceous Earth in Your Garden
When using DE in your garden, it is important to follow these guidelines to ensure that it is used effectively and safely:
- Wear a mask and gloves when applying DE to avoid inhaling the dust or getting it on your skin.
- Use food-grade DE, which is safe for pets, humans, and plants.
- Sprinkle DE around the base of plants or use it in a dust form to avoid direct contact with plants.
- Avoid using DE near flowering plants or where beneficial insects are active.
- Use DE sparingly to avoid drying out plants or altering soil pH levels.
Conclusion
Diatomaceous earth is a natural and non-toxic pest control remedy that can be used effectively and safely in your garden. While it is generally safe for plants, it is important to use it selectively and follow the guidelines for use to avoid any negative effects on your garden’s ecosystem.
FAQs About Diatomaceous Earth and Plant Safety
Here are some common questions and answers related to using diatomaceous earth in your garden:
Q: Is diatomaceous earth harmful to plants?
A: DE is generally safe for plants when used properly, but it can dry out plants and alter soil pH levels if used excessively.
Q: Can I spray diatomaceous earth directly on plants?
A: No, it is not recommended to spray DE directly on plants as it can dry them out and cause damage.
Q: How do I apply diatomaceous earth to my garden?
A: Sprinkle DE around the base of plants or use it in a dust form to avoid direct contact with plants. Wear gloves and a mask when applying to avoid inhaling the dust or getting it on your skin.
Q: Is diatomaceous earth safe for beneficial insects?
A: DE can be harmful to beneficial insects, so it is important to use it selectively and avoid using it near flowering plants or where beneficial insects are active.
Q: What type of diatomaceous earth should I use in my garden?
A: Use food-grade DE, which is safe for pets, humans, and plants.
Q: How much diatomaceous earth should I use in my garden?
A: Use DE sparingly to avoid drying out plants or altering soil pH levels. Follow the instructions on the product label for recommended usage rates.
References
1. Food and Agriculture Organization of the United Nations. (2013). Diatomaceous earth: Use and management for organic livestock production. http://www.fao.org/3/a-at540e.pdf
2. University of California Agriculture and Natural Resources. (2018). Diatomaceous earth. https://ucanr.edu/sites/ucmgnapa/files/298246.pdf
3. Michigan State University Extension. (2020). Using Diatomaceous Earth in the garden. https://www.canr.msu.edu/news/using_diatomaceous_earth_in_the_garden