Health Conditions A-Z Allergy 10 Worst Trees and Plants for Your Allergies Here's how to identify common allergy-causing plants and trees and hopefully avoid them. By Health.com Editorial Team Health.com Editorial Team The editors at Health are a dedicated team of experienced health editors, writers, and other media professionals who strive to bring trustworthy and responsible health and medical content to their readers. As a team, we have decades of experience in health journalism and have worked at legacy publishers and some of the biggest news and media companies in the U.S. health's editorial guidelines Published on July 31, 2014 Share Tweet Pin Email Hay fever, also known as allergic rhinitis, doesn't have anything to do with a fever, or hay for that matter. Instead, the watery eyes and stuffy nose are most often due to pollen from the beautiful plants and trees gracing your yard or neighborhood. (The condition was so named because it was discovered during haying season, when its symptoms were most present.) Warren V. Filley, MD, a spokesperson for the American Academy of Allergy, Asthma, and Immunology, gave us the lowdown on some of the most common allergy-causing plants and trees, and how to spot them. 9 Facts About Allergy Shots You Need to Know Before Deciding to Get Them 01 of 11 Ragweed Plant Getty Images Where you'll see it: Fields, riverbanks, roadsides, rural areas There's a ton in: Midwest and Mississippi River basin Peak time: Summer and fall "The most allergenic plant we have is ragweed," says Dr. Filley, "It is less common on the West Coast or in New England. Therefore there is less pollen in those areas." About 75% of Americans who have plant allergies are sensitive to ragweed, according to the Asthma and Allergy Foundation of America. 02 of 11 Mountain Cedar Tree Getty Images Where you'll see it: Mountainous areas (hence the name) There's a ton in: Arkansas, Missouri, parts of New Mexico, Oklahoma, and Texas Peak time: Spring "For the Texas hill country, it does not get any worse than the mountain cedar tree, which causes some of the most severe allergy symptoms I have ever seen," says Dr. Filley. When Is Allergy Season? 03 of 11 Ryegrass Getty Images Where you'll see it: Dry, cool lawns, meadows, pastures There's a ton in: Northern parts of the United States Peak time: Spring and summer Grasses as a whole are often problematic for allergy sufferers, says Dr. Filley. "There's no allergy-free grass. And if you mow it, you pick up mold as well as pollen." Other common allergens including timothy, blue, and orchard grasses. 04 of 11 Maple Tree Getty Images Where you'll see it: Along streams, woods There's a ton in: Eastern United States and Canada Peak time: Early spring Ash-leaf maple tree produces potent allergens and is found throughout the United States. Other, more moderate maples that trigger allergies are the red, silver, and sugar varieties. 05 of 11 Elm Tree Getty Images Where you'll see it: Cultivated, wetland habitats There's a ton in: Eastern and Midwestern United States Peak time: Spring (American Dutch elm); fall (lace bark elm) Dutch elm tree disease killed an estimated 100 million elm trees between 1930 and 1980. However, the trees made a comeback in the late 1990s. (Score one for the environment, zero for your allergies.) 06 of 11 Mulberry Trees Getty Images Where you'll see it: Woods, river valleys There's a ton in: Eastern United States Peak time: Winter to summer Flowering plants don't usually produce the most potent allergens. If it's pretty—think cherry and crabapple trees in blossom—it's probably "not" causing your misery. However, the mulberry tree has been known to contribute to hay fever. 07 of 11 Pecan Tree Getty Images Where you'll see it: Woods, orchards There's a ton in: the western fringe of the Southeastern United States, north Florida, Georgia, Indiana, and Ohio Peak time: Spring Pecans may taste great in pie, but in areas with lots of pecan trees, the pollen is second only to ragweed as a source of severe allergies. 08 of 11 Oak Tree Getty Images Where you'll see it: Woods There's a ton in: Coastal Plain from Texas to Virginia, and Florida Peak time: Spring "Oak trees produce less potent pollen but very large quantities," says Dr. Filley. Oak trees often produce the most pollen for the longest season. 11 Weird Things That Make Seasonal Allergies Worse 09 of 11 Pigweed/Tumbleweed Plant Where you'll see it: Lawns, roadsides There's a ton in: Western and northern United States Peak time: Spring to fall Other weed allergens in the West include Russian thistle and green molly (aka kochia or burning bush). 10 of 11 Arizona Cypress Tree Getty Images Where you'll see it: Well-drained soils There's a ton in: Southwestern United States Peak time: Spring In warm climates, this tree can cause pollen problems for six to seven months out of every year. 11 of 11 Mold Allergies Getty Images OK, we know, it's not a tree or a plant (it's a fungus). But we would be remiss if we didn't mention mold. If your allergies act up in spring, it may not be due to pollen circulating in the air, but mold levels that rise with wetter, warmer air. "Not to be left out are the molds, of which there are hundreds, which produce significant symptoms throughout the U.S., depending on time of year and activity," says Dr. Filley. Get accurate pollen and mold levels by using the National Allergy Bureau's tool, which measures pollen and mold levels by area. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit