RagweedRagweed is an annual plant or weed that is native to Eurasia but also present throughout North America. It can grow up to 5 ft tall, is hairy and light-green, and prefers sunny locations along roadsides, river banks, fields, gardens, and vacant lots. Ragweed is part of the Asteraceae family that includes: daisies, sunflowers, dandelions, and mugwort.

Ragweed, prior to being labeled a weed, had been introduced to some places as an ornamental plant for landscaping. Unfortunately for ragweed, it turned into a nuisance to landscaping and was discovered to be poisonous to some livestock. Despite its poisonous qualities it has been used in history for medicinal purposes such as treating:

  • Nausea/Vomiting
  • Fever
  • Stomach cramps
  • Diarrhea
  • Pneumonia
  • Insect bites
  • Rheumatoid arthritis
  • Allergies

Currently, there is little to no scientific evidence that ragweed is effective in treating any medical conditions.

When is ragweed pollen season?

Ragweed pollen is released in the late summer or early fall typically between July and October. Ragweed flowers, also known as flowerheads, are located at the tips of their stem turning green to yellow when bloomed. The male and female flowers of ragweed are located on the same plant. It is the male flower that produces the pollen necessary for pollinating the female flowers for reproduction. Once the male flowerheads blossom the ragweed pollen is carried by the wind to its female flowers.  Unfortunately, the wind also blows ragweed pollen into your home, on your clothes, and into the air where it will enter your nose, throat, and lungs. For this reason, many people experience allergies to ragweed pollen.

What allergy symptoms are caused by ragweed?

Ragweed pollen is very allergenic and along with birch tree pollen is one of the most common causes of hay fever. In people with allergies, when they come in contact with ragweed pollen their immune system thinks the pollen is an invader and begins an attack. This attack causes hay fever symptoms:

  • Itchy, water eyes
  • Runny nose
  • Sneezing
  • Itchy throat
  • Rash or hives
  • Facial swelling, especially around the eyes

In allergic people ragweed pollen can also lead to oral allergy syndrome.

Which foods have cross-reactions with ragweed?

Cross-reactions between ragweed pollen and foods can occur due to something known as oral allergy syndrome. With oral allergy syndrome you may experience an itchy mouth after eating raw fruits, vegetables, or nuts. (For more information on oral allergy syndrome click here). If you have a ragweed allergy you may experience cross-reactions with one or more of these foods:  banana, cantaloupe, cucumber, honeydew, watermelon, and zucchini. (To see a detailed oral allergy syndrome food list please click here).

Still have questions about ragweed?

For more information regarding the diagnosis of ragweed allergies related to oral allergy syndrome please click here.

For more information regarding the treatment of ragweed allergies related to oral allergy syndrome please click here.

For more information regarding ragweed allergies related to hay fever please click here.



Disclaimer: The information contained in this site is for educational purposes only, and should not be used as a substitute for a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition. Click here to read the full disclaimer.


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