Pollens
Three Groups of Pollen:
1. Trees - January to June, September and October
Cedar pollen is usually in the air in January, or occasionally as early as December in our area. It lasts well into February or early March. In February, other trees begin releasing their pollen. There are a few species of Elm and Hackberry that pollinate in the late fall in our area as well.

2. Grasses - April to September
Allergy to grass pollen is one of the most common allergies we see. Most people who are allergic to one grass are allergic to most of those that cause allergies in our area. Taking shots for allergy to two or three of the grasses usually helps build immunity to all of them.

3. Weeds - July to November
Ragweed is the most common weed to produce allergies in our area. Ragweed pollen is so small that it is easily carried in the air far from where it originated. Other common weeds that cause allergies in our area include cocklebur, lambs quarter, pigweed, English plantain, and sagebrush.

Two Types of Pollen:
1. Flowering plants - Flowers usually have sticky pollen that is easily carried by insects. The insects are attracted to these pretty plants, making it easy for pollination to occur. Because these pollens are large and heavy, they are not easily carried in the air. So they usually do not cause allergies.

2. Non-flowering plants - Most of the pollens that cause allergy symptoms are lightweight and easily carried in the air. Ragweed, for example, is so tiny and lightweight that it has been found out at sea, far from its original land source. Often when people think they are allergic to a flowering plant, it is really an allergy to a less noticeable plant that is in season at the same time.