Eastern Red Cedar (Juniperus virginiana): The Fencerow Juniper Ranchers Bulldoze That a 2022 USDA Peoria Study Confirmed Matches DEET on the Black-Legged Tick That Carries Lyme Disease

What is Eastern Red Cedar?

There is a way to walk the edge of your own woods in July, straight through the tall grass and the leaf litter where the ticks actually sit and wait, and come back to the house with nothing on you. It does not come in an aerosol can. It costs nothing. You do not order it and you do not mix it, and in most of this country it is already growing along the back edge of your property, in the fencerow, in the corner of the pasture nobody bothers to mow. There is also a fair chance you have paid a man with a chainsaw to take it out.

Close your eyes for a second and remember the smell of your grandmother's hope chest. The one at the foot of the bed, or the closet lined with pinkish-red planks, where the wool coats and the quilts went every spring. You have that smell in about two seconds, because nobody who grew up with it ever loses it. That smell is the exact thing we are talking about. It is the reason her coats came out of storage in October without a single hole in them, and she never once called it pest control. She called it furniture.

Then, in February 2022, a Department of Agriculture laboratory in Peoria, Illinois quietly published a result that took that old household smell and put it in a head-to-head test against the most famous chemical repellent in the world. Five species of ticks. Measured doses. And against the one tick that carries Lyme disease, the wood matched the chemical. The tree is the eastern red cedar (Juniperus virginiana).

From the 1580s Roanoke Colonists' "Tallest Reddest Cedars" to the 1920s Hope Chest & the Chicken Coop

1580s Roanoke: The Original Misnaming

Start where the colonists started. In the 1580s, English sailors landing at Roanoke Island looked up at a stand of dark evergreens and wrote home that they had found the tallest and reddest cedars in the world. They were wrong about the name. It is not a cedar at all - it is a juniper, Juniperus virginiana, in the cypress family (Cupressaceae). But they were right about the wood. Red cedar heartwood does not rot and does not warp. It cuts clean and it smells like nothing else in the forest. The wrong name stuck. To this day, half the products called "cedar" in North America (mulch, cedar chests, cedar chips, cedarwood oil) come from Juniperus virginiana.

The Colonial Toolkit

The colonists made everything out of it. Rail fences that outlived the men who split them. Cabin sills. Coffins. Pencils - the standard American pencil casing until the good red cedar timber ran short in the early twentieth century. Walk any old cemetery in Virginia or Tennessee and the posts still standing are red cedar. The USDA Forest Service records Juniperus virginiana as the most widely distributed conifer of tree size in the eastern United States - native in 37 states, found in every state east of the 100th meridian, and increasing across most of that range.

1920s-30s: The Cedar Hope Chest

And the colonists built chests out of it, because the oil locked in that heartwood repels the clothes moth. That was not folklore - it was the entire premise of an industry. Through the 1920s and 1930s a cedar hope chest was the standard gift for a young woman getting married, sold on exactly one promise: that what you put inside would come out in one piece. Lane, Roos, and half a dozen smaller manufacturers built the entire hope-chest category on a single molecule (cedrol) locked in the heartwood of a fencerow tree.

The Barnyard Knowledge

The same knowledge ran out into the barnyard. Farmers spread red cedar sawdust and shavings under the dog in the kennel and through the nest boxes in the chicken coop, to hold down the fleas and the smell. Nobody wrote a study on it. It was the kind of thing your grandfather did in April because his father did it in April.

Then, in One Generation, the Arrangement Came Apart

The chest went out of style first. Plastic totes were cheaper, mothballs were easier, and the wool coats ended up at the thrift store anyway. Out on the land, something worse happened. Fire suppression - the twentieth-century policy of putting out grassland fires that would once have kept red cedar in check - let the tree march out of the fencerows and into open pasture across the Great Plains. Ranchers began chaining it, dozing it, and burning it by the thousands of acres. A tree that abundant, that useful, and that close to hand - and the modern relationship with it is a burn pile while the family buys a spray bottle at the hardware store.

The 2022 USDA Peoria Study, Cedrol & the DEET Comparison

The National Center for Agricultural Utilization Research

The National Center for Agricultural Utilization Research (NCAUR) is a Department of Agriculture laboratory in Peoria, Illinois, and a group of its scientists had been working through American plant oils looking for something to put up against the synthetics. Their names are Lina Flor-Weiler, Robert Behle, Fred Eller, Ephantus Muturi, and Alejandro Rooney, and their results ran in the peer-reviewed journal Experimental and Applied Acarology in February 2022.

The Filter-Paper Bioassay

The test itself is almost homemade in its simplicity. They treated small squares of filter paper with measured amounts of cedarwood oil, clipped the paper onto short vertical rods, released tick nymphs at the bottom, and watched what happened when the ticks reached the treated zone.

Contact with that paper turned back between 80 and 94 percent of black-legged tick nymphs. The ticks retreated, slowed, or dropped off the rod entirely. And the black-legged tick nymph is the one that matters - it is the stage of the species Ixodes scapularis responsible for most Lyme disease transmission in this country.

Head-to-Head Against DEET

They ran the same nymphs against DEET, and the honest result is this: for four of the five tick species tested, DEET was the stronger repellent, and there is no reason to dress that up. But against black-legged tick nymphs, the oil out of the tree held them off just as well as the chemical the US Army built. Read that line again. On the single tick that sends Americans to the doctor, a fencerow juniper that ranchers pay contractors to remove drew even with the industry standard.

Cedrol: The Compound Doing the Work

The compound responsible is called cedrol - a sesquiterpene alcohol concentrated in the heartwood. In earlier laboratory work at the same center, Fred Eller and his colleagues found that cedrol did not merely turn those nymphs away. At the highest dose they tested, it killed all of them. Cedrol is also the primary compound responsible for the moth-repellent effect that made cedar hope chests work in the first place.

Why Cedar Products on a Store Shelf Are So Inconsistent

There is one more finding buried in that work, and it explains why cedar products on a store shelf vary so wildly. The traditional way to pull oil out of cedar shavings is steam distillation, which is inefficient and degrades the oil while it works. Eller and his colleagues showed that carbon dioxide under pressure - a method called supercritical fluid extraction - pulls roughly 30 percent more oil out of the same sawdust without cooking it. Two bottles wearing the same "cedarwood oil" label can be very different products.

Why It Stays Buried: Nootkatone Got a Patent, the Fencerow Cedar Got a Bulldozer

The Structural Explanation, Not a Conspiracy

So the obvious question is the one you are already asking. If a federal laboratory published this, why is the answer to tick season still a can of chemical?

There is no villain in a boardroom here. There is something plainer, and once you see it you cannot stop seeing it: you cannot patent a tree that grows in every fencerow from Nova Scotia to Texas. There is no revenue in something your neighbor will let you haul away for free. No revenue means no formulation, no packaging, no salesforce, no advertising budget, no doctor visits with product samples. The chemistry can be as strong as you want - if nobody can own it, nobody funds the machinery that would put it on the shelf.

The Nootkatone Comparison Case

The proof sits inside this very story. There is a related compound called nootkatone, found in Alaska yellow cedar and in grapefruit, that the Centers for Disease Control worked on for years against ticks. The Environmental Protection Agency registered it in 2020, and it moved to market as a branded, commercially-available tick repellent. That one got a company, a formulation, a label, and a price - because somebody could own it.

The tree behind your barn got a research paper and silence.

How to Use Eastern Red Cedar (Yard Barrier, Kennel & Coop, Skin Repellent & Hope Chest)

Four separate use cases, each with a different form of the tree. Match the form to the job.

1. Yard Barrier (Cedar Chips at the Woodline)

Nymph ticks wait in leaf litter and shade at the boundary where mown lawn meets brush or woods - that transition zone is the target, not the open grass. Lay down a band of red cedar chips or mulch 2 to 3 feet wide along that boundary. It is a real, measured barrier - and it is the same material sold as landscape mulch at any garden center. Refresh every 1-2 seasons as the scent (and the cedrol) fades. Combine with keeping the boundary itself well-mown.

2. Kennel & Chicken Coop (Cedar Shavings)

Cedar shavings under the dog bed, in the kennel run, and in chicken-coop nest boxes hold down fleas and reduce ammonia smell. This is the barnyard practice grandfather did in April - refresh when the cedar scent fades, because when the smell is gone, the oil is spent. Available as pet-store animal bedding or as smaller shavings for coop use.

3. Skin & Clothing Repellent (Diluted Cedarwood Oil)

For personal repellent use, dilute cedarwood oil in a carrier oil: a few drops per teaspoon of jojoba, sweet almond, or fractionated coconut oil, worked into boot leather, sock tops, and pant cuffs before you head out. Do NOT apply undiluted cedarwood oil to skin - it can irritate. Reapply every 2-3 hours on a hot day; it does not last as long as synthetics. This is a real repellent, not a chemical clone.

4. Hope Chest & Wool Storage (The Original 1920s-30s Use)

A cedar-lined chest stores wool coats and blankets moth-free through summer. If your grandmother's chest has stopped smelling, the wood is not finished - the surface has just oxidized over the decades and sealed the volatile oils inside. Take fine sandpaper (220-400 grit) lightly to the inside, and the smell (and the moth-repellent activity) comes roaring back out of it. Nothing ever left. It was sitting under there the whole time, the way the tree has been sitting out in the fencerow all along.

Critical Safety Notes

• Cats are the critical warning. Undiluted cedarwood oil is toxic to cats - their livers cannot metabolize the phenolic and monoterpene compounds the way ours do. Keep pure oil away from cats. Never apply cedarwood oil to a cat's skin or bedding. Cedar shavings in a chicken coop or dog kennel are fine; cedar shavings in a cat's litter or bedding area are not.
• Dilute before skin application. A few drops per teaspoon of a carrier oil is enough. Patch-test on your inner arm first for 24 hours if you have sensitive skin or known plant allergies.
• Cedar pollen is a known allergen in some regions (Texas "cedar fever"). If you know you react to Juniperus pollen, be cautious around actively pollinating male trees in winter.
• Cedarwood oil does not persist as long as DEET. Plan for reapplication every 2-3 hours on a hot day. It is genuinely effective on the Lyme tick nymph - but it is not a set-and-forget synthetic.
• Cedar berries (the pale blue "berries") are not the medicinal or repellent part. The active compound cedrol lives in the heartwood and the oil distilled from it. Berries are used by wildlife (cedar waxwings love them) and in flavoring gin from other juniper species.

How to Source Eastern Red Cedar (Identify, Forage, Grow & Buy)

1. Identify a Wild Tree (You Almost Certainly Have One Nearby)

Eastern red cedar is native to 37 US states and grows wild in every state east of the 100th meridian - almost certainly in a fencerow, pasture edge, or old field near you. Confirm all four features:

• SCALE-LIKE LEAVES pressed flat against the twig (not needles). Young trees may also show sharper juvenile needles - both are Juniperus.
• SQUARED-OFF TWIGS - roll a twig between your fingers and it feels four-sided, not round.
• SHAGGY REDDISH-BROWN BARK peeling in long vertical strips.
• PALE BLUE BERRIES (technically fleshy cones) about the size of a pea on the female trees in autumn.

Final confirmation: crush a sprig between your palms and smell it. You will be standing in front of that hope chest again. The smell is your confirmation.

2. Forage / Prune Responsibly

Take small branches with hand pruners for chips and shavings. Take heartwood only from trees that were going to be cut anyway - fencerow clearing, storm-fallen limbs, or ranch encroachment removal. In many parts of the Great Plains, ranchers actively pay contractors to remove these trees; a polite conversation with a landowner can often get you all the wood you can haul, for free.

Chip small branches through a garden chipper for yard-barrier mulch. Air-dry heartwood pieces for months, then plane, sand, or turn on a lathe for closet blocks or hope-chest lining boards.

3. Grow Your Own

Eastern red cedar tolerates almost any soil, is hardy in USDA zones 2-9, and is drought-resistant once established. Plant nursery seedlings in spring; expect 15-20 feet tall in 20 years. It is a slow but nearly bulletproof tree, and gives you a lifetime supply of prunings.

One ecological note: rangeland ecologists ask that you plant it inside a windbreak, hedge, or deliberate landscape rather than letting the wild ones encroach on open prairie. In its native range, contained plantings are welcome; unmanaged encroachment onto grassland is what the bulldozer problem is really about.

4. Buy Cedar Oil, Blocks, or Chips

Reputable suppliers stock cedarwood essential oil, cedar blocks and chips for closet and drawer storage, cedar mulch for yard-barrier use, and nursery trees. What to look for on a label:

• The Latin name spelled out: Juniperus virginiana. If it just says "cedar oil" with no species, treat it as consumer-grade - it could be from western red cedar, Texas cedar, or Atlas cedar, all with different chemistry.
• The extraction method named: steam-distilled or supercritical CO2. CO2-extracted oil is typically stronger and less degraded (about 30% more oil pulled out of the same sawdust, and volatile compounds not cooked).
• Cedrol percentage stated where possible - a serious product will disclose it. Higher cedrol = stronger tick/moth repellent activity.
• Organic or wildcrafted certification where available.
• For chips and mulch: 100% red cedar (not blended with other softwoods) and no added dyes.

Frequently Asked Questions

Is Eastern Red Cedar actually a cedar tree?

No - and the name is a 450-year-old case of mistaken identity. The English sailors who landed at Roanoke Island in the 1580s wrote home that they had found the "tallest and reddest cedars in the world." They were wrong about the genus. Eastern red cedar (Juniperus virginiana L., 1753) is a juniper, in the cypress family (Cupressaceae) - not a true cedar (Cedrus, Pinaceae, native to the Mediterranean and Himalayas).

True cedars have needle-shaped leaves clustered on short spur shoots and produce cones with scales in tight barrel-shaped cones. Eastern red cedar has scale-like leaves pressed flat against squared-off twigs, and its "berries" (technically fleshy cones) are pale blue and pea-sized. The USDA Forest Service records Juniperus virginiana as the most widely distributed conifer of tree size in the eastern United States - native in 37 states, found in every state east of the 100th meridian, and increasing across most of that range. The colonists gave it the wrong name; the wood, the identification, and everything downstream stuck. To this day, half the products called "cedar" in North America (mulch, cedar chests, cedar chips, cedarwood oil) come from Juniperus virginiana, not from any true Cedrus.

Does Eastern Red Cedar really repel ticks as well as DEET?

On the specific tick that matters most to Americans, yes - and the study is federal. In February 2022 a group of scientists at the National Center for Agricultural Utilization Research (NCAUR) - a USDA laboratory in Peoria, Illinois - published a paper in the journal Experimental and Applied Acarology (Flor-Weiler, Behle, Eller, Muturi, Rooney).

They treated small squares of filter paper with measured doses of cedarwood oil, clipped the paper onto short vertical rods, released tick nymphs at the bottom, and watched what happened when the ticks reached the treated zone. Against black-legged tick nymphs (Ixodes scapularis) - the stage of the species responsible for most Lyme disease transmission in the United States - contact with the treated paper turned back between 80 and 94 percent of the ticks.

They ran the same nymphs against DEET. On four of the five tick species tested, DEET was the stronger repellent. But on the black-legged tick nymph, the oil out of the tree held them off just as well as the chemical the US Army built. The compound doing the work is cedrol, a sesquiterpene. In earlier work at the same laboratory (Eller et al.), cedrol at the highest dose tested did not merely repel the nymphs - it killed all of them. One important caveat: cedarwood oil does not persist as long as DEET on skin and needs reapplying on a hot afternoon; it is a real repellent, not a chemical clone.

How do you use Eastern Red Cedar for tick and moth protection at home?

Four separate use cases, each with a different form of the tree.

1. Yard barrier. Nymph ticks wait in leaf litter and shade at the boundary where mown lawn meets brush or woods - that transition zone is the target, not the open grass. Lay down a band of red cedar chips 2 to 3 feet wide along that boundary. It is a real barrier, and it is the same material sold as landscape mulch at any garden center. Refresh every 1-2 seasons as the scent (and the cedrol) fades.
2. Kennel and chicken coop. Cedar shavings under the dog bed, in the kennel run, and in chicken-coop nest boxes hold down fleas and reduce ammonia smell. Refresh when the cedar scent fades - when the smell is gone, the oil is spent.
3. Skin & clothing repellent for yourself. Dilute cedarwood oil in a carrier: a few drops per teaspoon of jojoba, sweet almond, or fractionated coconut oil, worked into boot leather, sock tops, and pant cuffs. Do NOT apply undiluted cedarwood oil to skin. Reapply every 2-3 hours on a hot day.
4. Hope chest / wool storage. A cedar-lined chest stores wool coats and blankets moth-free through summer. If your grandmother's chest has stopped smelling, the wood is not finished - take fine sandpaper (220-400 grit) lightly to the inside and the smell (and the moth repellent) comes back.

CAT WARNING: undiluted cedarwood oil is TOXIC to cats - their liver cannot process phenolic and monoterpene compounds. Keep pure oil and heavily-treated items away from cats, and never apply cedarwood oil to a cat's skin or bedding.

What is cedrol, and why is cedar oil so inconsistent between brands?

Cedrol is the main sesquiterpene alcohol in Juniperus virginiana heartwood, and it is the compound doing most of the tick-repellent and clothes-moth-repellent work. The Eller et al. study at the USDA Peoria lab showed that pure cedrol, at the highest dose tested, killed all the tick nymphs it was applied to - not just repelled them. Cedrol also occurs in other cedar and juniper species at different concentrations, which is part of why not all "cedar oil" products behave the same.

But there is a second, larger reason for the variability on a store shelf: extraction method. The traditional way to pull oil out of cedar shavings is steam distillation, which is inefficient and degrades some of the volatile compounds while it works. A newer method - supercritical CO2 fluid extraction, developed and studied at the same USDA lab (Eller and colleagues) - uses pressurized carbon dioxide as the solvent, pulls roughly 30 percent more oil out of the same sawdust, and does not cook the oil in the process.

Two bottles wearing the same "cedarwood oil" label can be very different products. If a bottle names its species (look for Juniperus virginiana), gives an extraction method (steam-distilled or CO2-extracted), and states a cedrol percentage, you are looking at a serious product. If the label just says "cedar oil" with no species and no method, treat it as consumer-grade.

Where can you source Eastern Red Cedar - forage, prune, or buy?

Three routes.

(1) Identify and harvest from your own land. Eastern red cedar is native to 37 US states. Identification (all four checks): dense evergreen with scale-like leaves pressed flat against the twig (not needles); twigs feel squared-off when rolled between fingers; shaggy reddish-brown bark peeling in long vertical strips; pale blue berries about the size of a pea on the female trees in autumn. Crush a sprig between your palms and you will smell the exact scent of your grandmother's hope chest - that is your final confirmation. Take small branches with hand pruners for chips and shavings; take heartwood only from trees that were going to be cut anyway (fencerow clearing, storm-fallen limbs).

(2) Buy. Reputable suppliers stock cedarwood essential oil (Juniperus virginiana), cedar blocks and cedar chips for closet and drawer storage, cedar mulch for the yard-barrier use, and nursery trees. On a label, look for the Latin name spelled out; the extraction method named (steam-distilled or supercritical CO2); a stated cedrol percentage where possible; and, for chips and mulch, organic or wildcrafted certification.

(3) Grow your own. Eastern red cedar tolerates almost any soil, hardy in USDA zones 2-9, drought-resistant once established, and gives you a lifetime supply of prunings for chips, shavings, and berries. Plant nursery seedlings in spring; expect 15-20 feet tall in 20 years. Slow but nearly bulletproof. One note: plant it inside a deliberate landscape rather than letting wild ones encroach on open prairie - the rangeland "encroachment" that ranchers bulldoze is real ecological work, and containment matters.