Pollen Allergies

Pollen is one of the most common triggers of seasonal allergies. Many people know pollen allergy as “hay fever.” Experts usually refer to pollen allergy as “seasonal allergic rhinitis.”

Pollen Seasons in the U.S.

February – May: Trees (some start as early as December or January)

April – June: Grasses

July − November: Weeds

Each spring, summer, and fall − and even in the winter in some states − plants release tiny pollen grains to fertilize other plants of the same species. Most of the pollen that causes allergic reactions comes from trees, grasses, and weeds. These plants make small, light, and dry pollen grains that travel by the wind. They then can find their way into your eyes, nose, and lungs, causing allergy symptoms if you have a pollen allergy.

Flowering plants that spread their pollen by insects − like roses and some trees, like cherry and pear trees − usually do not cause allergic rhinitis.

There are three main types of pollen allergy: tree pollen allergy, grass pollen allergy, and weed pollen allergy.

Tree Pollen Allergy

Tree pollen is the first pollen to appear each year in the United States. It is responsible for most spring pollen allergy symptoms. It also often overlaps with grass pollen in the spring and summer.

Throughout the U.S., trees produce the most pollen from March through May. But in some regions, such as the South, trees may produce pollen as early as January and peak at multiple times during the year.¹

Some of the trees that cause the most allergy symptoms are:

Grass Pollen Allergy

If you have a grass pollen allergy, where you live may factor into when you have symptoms.

In Northern U.S, grass pollen usually appears in the late spring or early summer. In the South, grasses may release pollen during many seasons and could trigger symptoms throughout the year.

There are hundreds of types of grasses, but only a few cause allergy symptoms. Your location may determine which grasses may cause your symptoms.

Some of the most common types of grasses that cause allergy symptoms are:

• Bahia
• Bermuda
• Fescue
• Johnson
• Kentucky blue
• Timothy

Weed Pollen Allergy

Weed pollen, especially ragweed, causes allergy symptoms for many Americans. About 15% of people are allergic to ragweed pollen.²

Weed pollen appears in the late summer and fall. Ragweed grows in 49 states and can travel hundreds of miles in the air. This makes it hard to avoid.

Other weeds are also responsible for weed pollen allergy. Common weeds that can cause symptoms include:

• Ragweed
• Burning bush
• Cocklebur
• Lamb’s-quarters
• Mugwort
• Pigweed
• Russian thistle
• Sagebrush
• Tumbleweed