Allergic Living’s Tree Pollen Allergy Field Guide

in Outdoor Allergies, Tree Pollen
Published: April 16, 2014

Forty million Americans suffer with tree pollen allergies in spring. Do you know which trees are causing you grief? Allergic Living brings you this exclusive region-by-region field guide to the trees of allergies. Once you’ve found the enemy, find out what to do here.
For the Canadian guide, click here.

birch 2Male catkins hang off paper birch, spewing pollen widely to find a female match.

Spring is in the air. Which means across America, virile male trees are busily spreading their highly allergenic pollen. The microscopic grains float around like a fog, blanketing some areas with a yellowish-green mist.
Even when you can’t see pollen, it’s there, causing up to 40 million Americans to endure itchy eyes, painful congestion, running noses and sleepless nights.

Certain trees are notorious pollinators. Gender also plays a role: male dioecious (separate sexed) trees trigger the worst reactions, although monoecious (dual sexed) aren’t much better. Since avoidance is one of the strategies to fight hay fever, it’s helpful to know which trees are the most allergenic – and where to find them.

Tree Pollen Field Guide: Western States

juniper2Coloradans can thank the virile Juniper tree for their hay fever.

Juniper trees make spring the sneezing season in Colorado, says Susan Kirkpatrick, a certified pollen counter and an asthma educator with The William Storms Allergy Clinic in Colorado Springs. Poplar, cottonwood, aspen, elm, maple, alder and oak trees bring a parade of unhappy patients into clinics, too.

Finally, Coloradans should also beware the lodgepole pine, says Thomas Ogren, a horticulturist and author of Allergy-Free Gardening: The Revolutionary Guide to Healthy Landscaping.

In Washington state, it’s the cedar, juniper, alder, birch, poplar and cottonwood trees that bring on hay fever symptoms, says Dr. Frank Virant, who heads the division of allergy at Seattle Children’s Hospital. Also sure to trigger allergies for some western residents are walnut and holly trees.

Camphor TreeThese century-old camphor trees in L.A. are highly allergenic.

Down in California, the eucalyptus tree is emerging as a cause of seasonal symptoms – perhaps no surprise, given its ubiquity. “They say that you can drive from San Francisco to San Diego along the coast and never be out of sight of a eucalyptus tree,” says Ogren.

The silver wattle, almond and casuarinas (also known as beefwood or she-oaks) are some other relatively common allergy-producing trees in the west. Not to mention camphor trees. “The streets of Los Angeles are lined with camphor trees that are 100 years old and they’re gorgeous,” says Ogren. “But the people who live on those streets get quite miserable.”

Box ElderBox elder is a big trigger.


The allergy prone ought to also be wary of these other California trees: Catalpas (also called stogie trees, as native Indians used to dry the leaves, cut off the ends and smoke them like cigars); bottle brush, whose red flowers resemble baby-bottle brushes; Cryptomeria (also called Japanese cedar, these trees are the No. 1 cause of allergy in Japan, according to Ogren); Cyprus trees; box elder and ash-leaf maple.

Tree Pollen Allergy Tour: South Central

Texas has gained notoriety as an allergy hot spot, beginning even in winter, as the mountain cedar (in fact, not a cedar at all – it’s a species of juniper) pollinates and blankets entire sections of the state, says Virant.

Its allergenic reach stretches from Austin to Dallas and beyond. The Edwards Plateau in Texas has the largest population of the mountain cedar, also called Ashe Juniper or Juniperus ashei, which some claim is the biggest contributor to “cedar fever.”

The mountain cedar pollinates early in the season, and following close on its heels are the Eastern Red-Cedar, or Juniperus virginiana, as well as the oak – both seriously sneeze-inducing trees, which spread their windborne pollen through the end of spring.

Elsewhere in the south central region, cedars, elms, ash, maples, and box elders wreak havoc among allergy sufferers at this time of year.

Tree Pollen Allergy Tour: South Atlantic

In Florida, beware the olive tree. “Of all the trees, among the ones that are the most allergenic would be the olives, on a grain per grain basis,” says Ogren.

Palm treesTrouble in paradise; the palm is a relative of grass, and also allergenic.

A surprising offender to watch for is the palm tree, a favorite for low-water landscaping; Disney World, for example, has thousands of them. Unfortunately, they’re related to grasses, so if you’re allergic to grass pollen, you may also be sensitive to palm pollen.

The Chinese Pistache, too, is posing a problem in many areas. This hardy tree, which produces a beautiful fall color, is fast replacing another colorful tree, the Sweetgum, which is less allergenic but has aggressive roots that are destroying concrete sidewalks in many communities.

Florida is also home to the usual suspects that can be an allergy sufferer’s nightmare – junipers, cedars, elm and oak – as well as the casuarina, privet and laurel trees.

Next: Allergy Trees in North East & Mid-West U.S.