Ragweed is a green plant that resembles a fern.
What Is Ragweed?

Ragweed is a roadside plant whose pollen is the most common source of pollen allergens and hay fever. The states that have the most ragweed are in the central plains and eastern rural areas of the United States.
What Is Ragweed Season?
This late-blooming plant usually produces pollen in the early autumn. However, ragweed pollen can be detected as early as late July and usually peaks in mid-September. The season usually ends with the first frost sometime in late October or early November.
The amount of pollen in the air is dependent upon the weather. Pollen enjoys hot, dry, breezy days. These days cause big problems for hay fever sufferers. It is important if you suffer from hay fever to keep your doors, windows, and screens closed to reduce the amount of pollen entering your home. Well-maintained filters in central air-conditioning units may help remove pollen. If necessary, allergy drops or allergy shots with ragweed extract are effective for reducing symptoms.