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Poplar and aspen pollen

Poplar and aspen (Populus tremula, Populus species) is airborne here from april to may, peaking late April. Allergenic potency: low. No established food cross-reaction.

This is reference information, not a diagnosis and not a treatment plan. A pollen calendar cannot tell you what you are allergic to, and no page can clear a food as safe for you — only the label on the packet in your hand and the clinician who knows your history can do that. Anything beyond mild, short-lived symptoms in the mouth or nose — swelling that affects breathing or swallowing, hives away from the mouth, wheeze, vomiting or faintness — is an emergency question, not a reading question.

● peak weeks · ○ usually airborne. Typical mainland window from the national aerobiology monitoring programmes of the region · checked 2026-09-06

Where it grows here

Aspen is one of the commonest trees in Estonian, Latvian and Finnish forests, and hybrid poplars line roads and old parks in every city in the region. They flower on bare branches in April, dropping long reddish catkins onto pavements, and then — six to eight weeks later — release the white seed fluff that fills gutters in June.

When it is in the air

The pollen season is April into early May and it is short. The famous poplar "snow" of June is not the pollen season and has nothing to do with it: those are seed hairs, several millimetres long, far too large to be inhaled into the airways.

What it feels like

Poplar is a weak allergen and the symptoms attributed to it in late April usually belong to birch. Where poplar genuinely does cause trouble it is the ordinary picture: itchy eyes and nose on dry windy days when the catkins are open.

What it cross-reacts with

Poplar is not in the birch group and there is no established poplar food syndrome. Where poplar sensitisation shows up on a test it is often profilin — a protein present in nearly every plant — which produces positive results across many pollens and foods without necessarily producing symptoms from any of them.

Related pollens: willow, and other plants through profilin.

Foods: no established cross-reaction. That is a useful negative — a food reaction in someone sensitised to poplar and aspen is not explained by the pollen and deserves its own assessment.

Named allergen molecules: Pop n-type pollen proteins; profilin is the cross-reactive component. These are the official WHO/IUIS names, and they are what a component-resolved blood test reports.

What actually helps

The June fluff is a mechanical irritant rather than an allergen: it carries dust and it tickles, and for someone whose airways are already inflamed by the grass season starting at the same moment, it can feel like an allergic trigger. A closed window and a rinse of the face does more than an antihistamine.

What gets misread

This is the most misattributed plant on the whole calendar. Every June, poplar fluff is blamed for symptoms that belong to grass pollen, which peaks in exactly those weeks. If your worst weeks are the ones with fluff in the air, look at the grass row of the calendar before the poplar one.

Sources: Regulation (EU) No 1169/2011, Annex II · Commission Implementing Regulation (EU) No 828/2014 (gluten claims) · WHO/IUIS Allergen Nomenclature · season windows from the national aerobiology monitoring programmes of Estonia, Finland, Sweden, Denmark and Norway · cross-reaction patterns paraphrased from the allergy literature and EAACI material · checked 2026-09-06

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