10 Worst Plants for Your Allergies

• 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.

Where you’ll see it

: Fields, riverbanks, roadsides, rural areas

There’s a ton in: the Midwest, the 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.

Where you’ll see it

: Mountainous areas (hence the name)

There’s a ton in: Arkansas, Missouri, parts of New Mexico, Oklahoma, 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.

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.

Where you’ll see it

: Along streams, woods

There’s a ton in: the Eastern United States and Canada

Peak time: Early spring

Ash-leaf maple produces potent allergens and is found throughout the United States. Other, more moderate maples that trigger allergies are the red, silver, and sugar varieties.

Where you’ll see it

: Cultivated, wetland habitats

There’s a ton in: the Eastern and Midwestern United States

Peak time: Spring (American Dutch elm); fall (lace bark elm)

Dutch elm 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.)

Where you’ll see it

: Woods, river valleys

There’s a ton in: the 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 has been known to contribute to hay fever.

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.

Where you’ll see it

: Woods

There’s a ton in: the Coastal Plain from Texas to Virginia, and Florida

Peak time: Spring

“Oak produces less potent pollen but very large quantities,” says Dr. Filley. Oak trees often produce the most pollen for the longest season.

Where you’ll see it

: Lawns, roadsides

There’s a ton in: The 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).

Where you’ll see it

: Well-drained soils

There’s a ton in: the Southwestern United States

Peak time: Spring

In warm climates, this tree can cause pollen problems for six to seven months out of every year.

OK, we know, it’s not 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.