Sagebrush pollen allergy
Artemisia
Sagebrush is an aromatic shrub of the western US whose wind-borne pollen adds to late-summer and fall hay fever. Its pollen allergens closely match those of mugwort.
What it is
Sagebrushes are shrubs in the genus Artemisia. Utah State University’s range plant guide places big sagebrush (Artemisia tridentata) in valleys, basins and on mountain slopes between 2,500 and 10,000 feet.2 One subspecies, Wyoming big sagebrush, occupies the largest area of the big sagebrush types. It is an aromatic, evergreen shrub that is usually under 40 inches tall and occasionally reaches about 79 inches.1
Sagebrush belongs to the same large plant family as ragweed, and like ragweed it can spread its pollen by wind. Mugwort is another member of that family.3 Mugwort (Artemisia vulgaris) shares sagebrush’s genus. It is a weed introduced from Europe that has spread through the northeastern US, into southern Canada and along the Pacific Coast from Washington to central California.4
The Artemisia species resemble each other as allergens. A 2019 lab study tested pollen from seven Artemisia species, including big sagebrush and mugwort, with blood serum from people allergic to mugwort pollen. The six species other than mugwort each carried a close relative of Art v 1, the major mugwort pollen allergen, and these proteins cross-reacted. The authors concluded that related Artemisia species should also be considered causes of allergy.5
Symptoms it causes
Sagebrush pollen can cause symptoms when it is breathed in. ACAAI lists sagebrush and mugwort among the weeds that cause seasonal allergies, and wind-pollinated plants like these are the ones most likely to cause a seasonal allergic reaction.6
Hay fever can bring a runny or stuffy nose, sneezing, itchy eyes, mouth or skin, and tiredness from poor sleep.7 An allergist can find out which pollens are behind the symptoms, for example with a skin test that introduces tiny amounts of suspected allergens into the skin.7
Where and when it grows
Wyoming big sagebrush is native to the western United States and British Columbia. It grows in 14 states: Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming.1 About 70% of North America’s sagebrush is in three regions: the Columbia Basin, the Great Basin and the Wyoming Basin.1
Sagebrush flowers late in the year. Wyoming big sagebrush usually flowers and is pollinated from midsummer to late fall, starting as early as mid-July and lasting as late as November, depending on climate and elevation.1 Utah State University’s range plant guide gives August to September for big sagebrush.2
That timing overlaps the main weed pollen season, which runs from August until the first hard frost.8 Ohio State University’s weed guide says mugwort blooms from July to September.4
Cross-reactions
| Can also react to | What happens |
|---|---|
| Mugwort and other Artemisia pollen | In a 2019 lab study using serum from 11 people in Austria allergic to mugwort pollen, six other Artemisia species, big sagebrush among them, each carried a close, cross-reactive relative of Art v 1, mugwort’s major pollen allergen.5 |
Symptoms it can cause
When to get help
See an allergist if
- Allergy symptoms last for several months of the year
- Allergies bring repeated sinus problems, a blocked nose or trouble breathing
- Over-the-counter remedies don’t control your symptoms
- Allergies or asthma get in the way of daily life
- You often wheeze, cough at night or after exercise, or feel short of breath
Based on ACAAI’s “When To See an Allergist”. General information, not medical advice.
Questions
Is mugwort related to sagebrush?
Yes. Mugwort (Artemisia vulgaris) and big sagebrush (Artemisia tridentata) are both species of Artemisia, and their pollens carry closely related, cross-reactive allergens.5
When does sagebrush release pollen?
Wyoming big sagebrush usually flowers and is pollinated from midsummer to late fall. Flowering can start as early as mid-July or run as late as November, depending on climate and elevation.1
Can sagebrush cause hay fever?
It can. ACAAI lists sagebrush among the weeds that cause seasonal allergies, and notes that wind-pollinated plants like these are the most likely to cause a seasonal allergic reaction.6
Sources
- Artemisia tridentata subsp. wyomingensis, Wyoming big sagebrush. USDA Forest Service, Fire Effects Information System. Read on October 15, 2026.
- Big Sagebrush. Utah State University Extension, Range Plants of Utah. Read on October 15, 2026.
- Ragweed Pollen Allergy. Asthma and Allergy Foundation of America. Read on October 15, 2026.
- Mugwort (Artemisia vulgaris). Ohio State University, Ohio Perennial and Biennial Weed Guide. Read on October 15, 2026.
- Similar Allergenicity to Different Artemisia Species Is a Consequence of Highly Cross-Reactive Art v 1-Like Molecules. Medicina (via PubMed Central). Read on October 15, 2026.
- Gardening with Allergies. American College of Allergy, Asthma and Immunology. Read on October 15, 2026.
- Hay Fever. American College of Allergy, Asthma and Immunology. Read on October 15, 2026.
- Pollen Allergy. Asthma and Allergy Foundation of America. Read on October 15, 2026.