Tree Pollen
Description
Trees produce oxygen, clean the air, support wildlife, and provide shade — but many species also release significant amounts of pollen during their reproductive cycles, making them a major allergen source. Common allergenic trees include birch, oak, alder, hazel, ash, cedar, cypress, maple, and pine. Tree pollen allergies typically cause symptoms in spring, though some species pollinate in winter or fall.
Allergy Symptoms
Tree pollen causes:
- Sneezing and runny or congested nose
- Itchy, watery, red eyes
- Coughing and throat irritation
- Asthma flare-ups and wheezing
- Itchy skin or hives in some people
Many people with tree pollen allergies experience Oral Allergy Syndrome (OAS) — itching or swelling of the mouth and throat after eating certain raw fruits, vegetables, or nuts. This happens because proteins in some foods resemble those in tree pollen. Birch allergies, for example, commonly cross-react with apples, pears, cherries, hazelnuts, and carrots. Cooking these foods usually reduces or eliminates the reaction.
Typical Pollination Period
Tree pollen seasons vary by species and location:
- United Kingdom: February to June, with hazel and alder starting earliest
- United States: Spring for most trees, starting as early as January in the South and extending into May or June in the North
- Europe: Early-pollinating trees like hazel and alder can release pollen from December to April
Geographic Distribution
Allergenic trees grow worldwide:
- Urban areas: Cities typically have a mix of native and ornamental trees contributing to pollen levels
- Rural areas: Forests and woodlands with high tree density can mean significant pollen exposure during pollination
- Coastal regions: Areas near the sea may have lower pollen levels due to offshore winds, though this varies
Tips for Allergy Sufferers
- Check local pollen forecasts and limit time outdoors when counts are high
- Keep windows closed and use HEPA air purifiers
- Shower and change clothes after being outside
- Antihistamines or nasal corticosteroids can help — ask your doctor
- If you get OAS, watch for cross-reactive foods during tree pollen season
- Consider allergy testing to identify which trees affect you
- For persistent symptoms, immunotherapy can help