Summer is here and that means growing season is in full swing. Hay fever, also known as allergic rhinitis, does not 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.)

One of our greatest nasal irritants is ragweed. About 75% of Americans who have plant allergies are sensitive to ragweed, according to the Asthma and Allergy Foundation of America. Ragweed pollen is a common allergen. A single plant may produce about a billion grains of pollen per season, and the pollen is transported on the wind.

However you pronounce them pecans taste great. But the trees that produce them give us something not quite so tasty. 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. The tree flowers in spring, shedding enormous quantities of pollen. The pollen season extends from April to June in the Northern Hemisphere. Pollination occurs by wind.

Oaks are a particularly large genus, with various species growing throughout the U.S. They are commonly found in residential areas, as well as parks, and remote forests. The trees are large, reaching heights of 150 feet. The plants contain both male and female flowering parts, meaning they produce pollen, and can be pollinated, too, either by themselves, or by other plants. These trees are common throughout residential areas and parks — so the pollen potential is very high. Oaks cause real seasonal suffering for people with oak pollen allergies because the trees have a long period of pollen production.

Allergies can produce many of the same cold-like symptoms as a sinus infection, including sinus pressure, a runny nose and congestion. But the condition itself, called allergic rhinitis, is different. It is caused by an allergic response to allergens, such as pollen, dust mites or pet dander. This reaction happens when your immune system releases chemicals, such as histamine, into your bloodstream. These immune system chemicals lead to your allergy symptoms.