Wednesday, October 13, 2010

Diatomaceous Earth

Copyright Harvest McCampbell 5/23/07 Published in the Hoopa People News

Diatomaceous earth offers organic farms, gardens, and households a non-toxic way to control many pests. It is made up of the fossilized remains of microscopic diatoms that once floated through ancient tropical seas. This product is mined from naturally occurring deposits, then purified and prepared for a number of uses. Food and agriculture grade diatomaceous earth is non-toxic to humans, mammals, and other higher animals. It is so non-toxic that it is sometimes added to food. DE, as it is often called, provides pest control by microscopic razor like edges that lacerate pest’s exo-skeletons and tender tissues. Death, generally by dehydration, is the fate of the pests that are susceptible.

Many common house and garden pests are equipped with an exo-skeleton. Think about the hard shells on ants, fleas, and beetles and you will get the idea. Even those squishy aphids and flour moths have exo-skeletons; theirs are just thin – making death by DE a quick proposition. In addition to its use in the garden, it can be used around the house, and diatomaceous earth can be added to stored seeds to prevent insect infestation.

Some organic packaged food products made for people and pets actually contain tiny amounts of food grade DE to prevent insect infestation. Diatomaceous earth is not readily digestible. What we do metabolize provides minute amounts of calcium and trace minerals. The undigested DE actually has another benefit. As it moves through the digestive track it lacerates any intestinal parasites it comes in contact with! It may seem a strange role reversal, but parasites equipped with an exo-skeleton are soon digested by their host.

DE is also inexpensive and easy to use in the home and garden. First, there are some careful considerations we each should make before adding it to our environments. One has to do with its possible irritant affects, and the other has to do with its permanence. Prolonged breathing or eye contact with the dust can be very irritating. While this is more of a problem for workers on organic farms than for those of us who are puttering around at home - it is still a good thing to keep in mind. Dust masks are advised as well as some care to avoid using on windy days and those with asthma or other respiratory ailments.

On the permanence factor, once diatomaceous earth has made its way into your soil, it’s there for good. Since it only works on contact and must be reapplied when it washes off, lots of DE can build up in the soil with repeated use. Think of it as teeny tiny grains of rock or sand. It is not a chemical that will degrade over time and it’s not likely to leach out by the actions of irrigation or winter storms. That longevity is both good and bad. The DE is there working for you - but it is not selective. It harms both the pests that attack our crops as well as the good bugs that attack the pests. While I have not heard of any pests adapting thicker exo-skeletons in response to exposure to DE, it is bound to happen. The pest species are always more adaptable than the predators, so when it does happen the DE will still be killing off the good guys while the bad guys reproduce out of control. Something like this is already going on with commercial farming. Farmers need more and more poison to control rapidly adapting pests, while the chemicals quickly wipe out the predators.

All that said I have used DE around my homes for the last 30 years. I am selective about where I use it because I want to encourage beneficial insects. Many beneficials spend their larval stage as grubs in the soil, so I try to keep the DE out of the garden. However, I find it very useful on my back porch, where my young seedlings are just getting started. It effectively discourages slugs, aphids, and most other pests. I also add DE to the seeds that I save from the garden. So far there have been no bugs in my DE treated seeds. Last but not least, I use DE on my pets for its flea controlling effects. I have a certain spot in the back yard that I use when I dust them with DE. It is a spot where they spend lots of time. The DE that hits the ground will control flea larva, which helps break the flea infestation cycle. (DE alone doesn’t seem able to solve the flea problem, but it definitely helps. If enough people are interested in natural flea control we can cover it in an upcoming article.)

When I use DE, I generally fill a small muslin bag with the powder, hold my breath or use a mask, and shake the bag to apply. It can also be dispensed from an old salt or pepper shaker that is labeled and kept with your garden supplies. You can sprinkle DE along base boards, behind furniture, into cracks and crevices in the kitchen, bathroom, and along windows and doors. This will help eliminate ants, fleas, cockroaches, and other pests at their points of entry and along any travel routes they may have established. They will also carry the dust back to their nests, helping to control the pests right at their sites of origin. If fleas are the main problem, besides dusting your animals, you can also dust their bedding and even your own mattresses (but not your bedding- you don’t want to breathe the dust all night).

Dusting your mattress is also recommended for control of bed bugs. You may come across recommendations to use the dust on furniture and carpet, having done it I don’t recommend it, unless there is no acceptable alternative. I find it quickly ages fabric and carpets, especially in high use areas. The friction of walking on the carpet and using the furniture causes those tiny razor edges to abrade the fibers. Your fabric will look dull and frayed before its time.

DE can be purchased in bulk and is sometimes available as prepackaged combination products. It is available from many organic nurseries and larger natural food outlets. If you can’t find it locally check out St. Gabriel Laboratories at or call to request a brochure (800) 801-0061. They carry DE (both wholesale and retail) in bulk as well as a product made to use in the kitchen called the AntEater. The Anteater contains food grade DE and clove oil, but it is not meant to be consumed. This product smells great and it is safe to use around stored food. The packaging is equipped with a special dispenser that makes it easy to apply to the cracks and crevices where insects lurk and where simply shaking wouldn’t be effective. They also have a number of other products available for organic farms and gardens. Check them out--but always do your own research or ask experienced gardeners before using unfamiliar products.


Harvest said...

Be sure to read the product descriptions and directions before purchasing and using. DE that is not food grade should not be used around food or in the kitchen. Food grade DE can be used in the garden, but DE that is used for pool filters and other uses will not be effective in the garden. Some people recommend using goggles and wearing long sleeved shirts and gloves. As DE can irritate the eyes, goggles are a good idea. It can be very drying to the skin, and some people do find it irritating. If you are using it for more than a spot application long sleeved shirts and gloves may be a good idea.

Anonymous said...

I have been doing a lot of research into DE and thus found this site. I learned some say it is not good to put into the garden (or farm soil I'd say) to get the insects because it will also hurt bees,lady bugs and other good insects. I think micro life approach needs to be done, just as good micro life in the soil do well. Bad bungs are abundant in lacking soils anyway. Treating soil with good living life is the key.