5 Cool Facts about Mountain Cedar (Ashe Juniper)

Before moving to San Antonio, Texas I had never heard of Ashe Juniper (Juniperus ashei). Often called by the common name Mountain Cedar trees by locals, it is the cause of the dreaded “Cedar Fever”. It didn’t take long after moving here to feel the symptoms of an allergic reaction – the runny nose, watery eyes, sore throat, and headache!

I now succumb to the allergy each Mountain Cedar season, as the male Ashe Juniper trees unleash their clouds of pollen during this time of year. The pollen count can be off the chart between December and February!

Mountain cedar (Ashe Juniper) can cause seasonal allergies and symptoms of cedar fever.
Mountain Cedar pollen can cause allergic rhinitis after a cold front.

Many allergy sufferers like myself have to get allergy shots or use nasal sprays to combat the juniper pollen, so it’s no wonder they aren’t a fan of Mountain Cedar. However, the more I learn about this native Texas tree, the more I have grown to appreciate it rather than despise it!

I thought I would try to improve its reputation by sharing some cool facts. First, here is a little more about it if you are new to this evergreen tree:

Is Mountain Cedar Really a Cedar Tree?

First, let’s dispel a common misunderstanding. Even though these trees are commonly called “Mountain Cedar”, they are not Cedar trees! When the first Europeans saw them they thought they resembled the Cedar trees of Europe and the name stuck. However, the trees are actually Ashe Junipers, part of the Cypress family of trees. True Cedar trees are part of the Pine family.

Scientific Name: Juniperus ashei

The scientific name for Ashe Juniper just sounds like a fancy version of it: Juniperus ashei. You can start using that name to impress all your friends!

Common Names

Like all plants, Juniperus ashei has one scientific name but many common names. In addition to Mountain Cedar, other common names for Ashe Juniper include Post Cedar and Texas Cedar among others.

Is Ashe Juniper native to Texas?

According to the USDA, Ashe Juniper is native to the following states:

  • Arkansas
  • Missouri
  • Oklahoma
  • Texas

However, some of the biggest concentrations of Ashe Juniper can be found right here in the Texas Hill Country and Edwards Plateau area where I live! It is one of six different types of Juniper trees native to Texas.

Male Ashe Juniper (Mountain cedar) with pollen.
My kitchen window vantage point of our neighbors’ Cedar tree where you can see a cloud of pollen on windy days!

5 Cool Facts about Mountain Cedar (Ashe Juniper)

1. It has been around for thousands of years

According to research at Baylor University, Ashe Juniper has been growing in the United States since the late Pleistocene era. That is as far back as 125,000 years ago. Ashe Juniper was growing when mammoths and saber-toothed tigers roamed the Earth. Talk about a hardy tree!

2. There is a lot more of it now than before European settlers

It is hard to picture a Texas Hill Country landscape without seeing Live Oak and Ashe Juniper trees as far as the eye can see. However, this wasn’t always the case. Early European explorers mention dense “Cedar brakes” growing along limestone canyons in their travels across the Texas Hill Country.

Ashe Juniper was definitely around, but primarily limited to hillsides and interspersed between vast grasslands.

Without natural fires to control its growth, Ashe Juniper has exploded to form dense thickets in natural areas and private ranches. Too much Mountain Cedar is not necessarily a good thing. Managing its growth is important to maintaining biodiversity.

A golden-cheeked warbler on the cover of a Central Texas Bird Guide.
The golden-cheeked warbler, which only nests in Ashe Juniper trees in the Texas Hill Country.

3. It exclusively supports an endangered species

However, the prevalence of Ashe Juniper is not a bad thing if you are a Golden Cheeked Warbler! This beautiful songbird is endangered and only nests in the Texas Hill Country. It uses the bark of Ashe Juniper trees almost exclusively to build its nests. Without Ashe Junipers there would be no Golden Cheeked Warblers.

Fun fact: I saw my first Golden Cheeked Warbler when we spent a weekend in Utopia, TX last summer. I was standing quietly by a stream watching some birds play in the water, when a Golden Cheek Warbler landed on a low branch of a tree a few feet from me.

I couldn’t believe my eyes! It was close enough to reach out and touch. I was dying to reach for my camera, I didn’t want to scare it away. So you’ll just have to take my word for it!

Bark of an old growth Ashe Juniper (Mountain Cedar) tree used by Golden Cheeked Warblers for their nests.
Golden Cheeked Warblers make their nests almost exclusively from Ashe Juniper bark.

4. Female trees create “berries”, males create pollen

If you see a Mountain Cedar tree with billows of yellow pollen “smoke” coming off it in January, that is a male tree. There is a large male tree in our neighbors’ backyard, and I have a prime viewing spot of it from our kitchen window. I watch as its evergreen needles turn from green to yellow as the tree pollen is released.

If you see a Cedar tree with dark blue fruit, those are actually the fleshy cones of the female tree. The “berries” provide an important food sources to birds and small mammals. Humans can also eat them, and apparently you can make them into a jam if you are very adventurous!

The blue berries of a female Ashe Juniper (Mountain Cedar) tree are actually fleshy cones.
The fleshy cones of the female Ashe Juniper look like blue berries. They are a source of food for wildlife.

5. It is a larval host plant

A native plant that serves as a host plant to butterflies and moths is always a good thing. It turns out that this tree is the host plant to the Juniper Hairstreak Butterfly. It lays its eggs in Juniper trees.

Remember Mountain Cedar is a Friend, Not a Foe!

From now on when you see a Mountain Cedar, you can show off your new knowledge by calling it by its more accurate name – Ashe Juniper. Or for brownie points, call it by its scientific name Juniperus ashei!

Remember, Mountain Cedar isn’t just the cause of stuffed nasal passages, incessant sneezing, and itchy eyes! It is also an important nesting home to the endangered Golden-Cheeked Warbler, an important source of berries for wildlife, and a nursery for caterpillars of the Juniper Hairstreak. More caterpillars means more food for birds.

Learn more about these important ecological connections in my Top 6 Benefits of Native Plants in Your Yard.

5 cool facts about Mountain Cedar

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