the Science behind the Magic of Cedar Oil

the Science behind
the Magic of Cedar Oil

In a world poisoned by 20th Century pesticides containing toxic organo-phosphates and other chemicals, cedar oil products offer an effective non-chemical alternative.

One must choose the right cedar oil product with great care, as there is much marketing confusion.  There are many different cedar oil products on the market, each with cedar oil as an active ingredient, but there are differing concentrations, as well as different inert ingredients, each intended for different purposes.

cedar tree leaves

" . . .  Berries and all plants growing in cedar forests are richer in vitamins and provitamins than those growing in other forests. . . "    ​more info below​​​


Yard Guard cedar oil formula

RTU:  Consumer product:  ​Available in 2 sizes: RTU quarts w/ hose end sprayer or RTU gallon jug refill

Concentrations can range from 85%-90% cedar oil / 10-15% inert ingredient, to 17-20% concentrations blended largely with water or even 10% cedar oil, 90% carrier agent.  

Inert ingredients might be (organic) ethyl lactate (a corn oil by-product), Hydrated Silica (Silicic Acid aka melted quartz rock), or even Polysorbate 20, aka polyethylene glycol sorbitan monolaurate (a synthetic chemical, definitely not organic).   Some are sold diluted further with up to 80% water, some are not. Some are safe around pets, some not. Some are safe to use around plants --- some are not. Some are better for outdoor and others are formulated specifically for indoors.

Confused yet?
Each formulation solves a unique subset of insect issues, though many of the formulas overlap. Some are "large molecule" formulas, some are "small molecule" formulas, rendering them more effective on some insects. One almost needs to be a chemist to surf the hype!

​Promising Test Results and Field Endorsements:

​Cedar oil formulas have been extensively tested for use to control subterranean insects such as termites and even nematodes and grubs.  (#1)

In tests conducted by Rutgers University, one early cedar oil blend showed great promise against bed bugs including eggs when applied directly, (#2 & #3), giving rise to more research.  Now we have formulations used by professional exterminators in some areas of the US,  according to specific protocols just for bed bugs.

The US Army used a cedar oil formula to combat sand fleas in the Middle East deserts. (#4)

Field endorsements can be found  with a simple google search:

Endorsed by a chemical spray technician for the Parks and Recreation Department of West Palm Beach. (#5)
Endorsed by the USDA leading scientist Dr. Joe M. Bradford (#6)

​. . . and numerous comments by consumers in feedback who have tried individual products.

cedar tree

cedar tree up close

​Not Just Any Cedar Tree.

There are some 335 species of cedar trees on planet earth, and 100 are not really cedar trees at all, but are cypress trees.  And cedar oil contains more than 100 different sub elements, half of which don't even have a name.

Out of this diversity comes many different grades of cedar oil, suited to different purposes.  In the US, cedar oil is mainly harvested from 3 species:  Western Red Cedar,  Eastern Red Cedar, and Texas Red Cedar.   While the Thuja Plicata, aka Western Red Cedar, contains properties that are harmful to animals and especially cats, the Eastern and Texas Red Cedar are completely different trees, chemically speaking.

Western Red Cedar is wonderful for making outdoor furniture, and playground equipment, but is toxic to both humans and animals in some of the other forms.  Juniperus Virginiana L. Cupressaceae, Eastern Red Cedar or Virginia cedar, and Juniperus ashei or mexicana, aka the Texas Red Cedar, each contain more of the insect and parasite repelling properties than normally found in other cedars.

For an in-depth look at the chemical compounds of cedarwood oils, see page 8 of this document prepared for NCI regarding cedarwood oil:

​Hence, all cedar trees aren't alike!

Not Just Any Cedar Oil

​Cedar Oil is a complex substance and its composition varies greatly depending on both the species of tree used and the extraction process used.  It can be made even safer by the removal of certain naturally occurring toxic compounds.

Texas red cedar oil is the oil of choice used in many of the more successful pest control formulas. It is an insect control grade cedar oil that has been scientifically studied and found to contain more of the insect repelling properties than other sources.

It is obtained by steam distillation of chopped wood from Juniperus ashei or Juniperus mexicana, a native shrub in the state of Texas. (#7)

The cedar wood used is found on ranches from previous clearing operations for livestock grazing.  It is then additionally modified by a proprietary fractionating process to eliminate the phenols and terpenes, toxic substances to cats and small animals. There are only a few manufacturers that use this fractionating process.  Hence the term "modified Texas Red Cedar Oil".

Not Just Any Cedar Oil

PCO CHOICE back label

PRO-CHOICE: professional strength concentrate

​How Safe Is Cedar Oil?


​Cedar oil was first registered in 1960 as a pesticide to repel moths from clothing. In the face of enormous positive scientific research, by 1996, the EPA deregulated cedarwood oil and no longer requires cedar oil manufacturers to register the oil as a pesticide.


Cedar oil is not listed as  a hazardous substance, priority pollutant or toxic pollutant under the Clean Water Act.

​OSHA doesn't regulate cedar oil.

The American Conference of Governmental Industrial Hygienists (ACGIH) doesn't list cedar oil on its Threshold Limit Value (TLV) or Biological Exposure Index (BEI).

Alcohols and terpenes derived from cedar are listed as food additives with the US Food and Drug Administration (FDA) and labeled as Generally Recognized as Safe (GRAS).


#1:   USDA Research Leader Dr. Joe M. Bradford Endorses Agricultural Industry Breakthrough

#2:   Cedar Oil Blend Products



#5:   &


#7: Texas cedarwood oil is obtained by steam distillation of chopped wood from Juniperus ashei or Juniperus mexicana.

#8 How Safe is Cedar Oil

​additional references:
The History of Cedar Oil

About the author

Green Genie

The Green Genie is the voice of AskTheGreenGenie brand -- organic, edible landscaping for home gardening made fun ! We're passionate about helping home gardeners to get more out of their gardens and enjoy the fruits of their labors -- literally. Organic gardening is a given. Fight pests effectively and actually win the battles. Oh, and palm trees -- I know, they're not all edible, but we love the ambiance!