Its the same spectacle every year: Berlins streets are flooded with some weird cotton pollen just as the summer starts kicking in. When a light breeze brushes through the streets – the fluffy white clouds spread out and one could be lead to believe that its started snowing. Almost. But what exactly is that white cotton stuff which is so prone to flying in your eyes and mouth when you’re cycling (or walking) through Berlin?
Well first things first: Its not pollen! They are seeds from the Populus tree (Pappeln in German) – otherwise known as Poplar, Aspen and Cottonwood (all different trees but they are the same species), and quite a few streets and parks in Berlin are lined with them.
In fact, Berlins got over 10,000 of them – that’s almost 3% of all trees in Berlin and each one of these trees produces up to 28 million seeds. At the beginning of the summer when it gets warmer in the city, the trees jettison the seeds en masse sending them through the air creating a mass phenomenon which is known in German as „Pappelschnee“ or „Sommerschnee“ – Poplar Snow or Summer Snow.
Allergists often misattribute their pollen allergy to the white cotton floating through the air, but its actually the grass pollen which is triggered by the heat at the same time which makes their life unbearable. As innocent as the poplar seeds seem to be, they tend to be highly flammable – often catching fire when a passerby carelessly throws out his cigarette (In Geman: Link and Link). They don’t just burn though – poplar “cotton” is smoother than silk and makes for an excellent (albeit pricey) pillow and comforter filling.
As quickly as the white cotton seeds appear do they disappear again. The Aspen/Poplar/Cottonwood trees only bloom for 2 weeks, and whats left of the Poplar Snow is washed down the drain by Berlins summer storms. The more you know.
Yesterday, I spent twenty minutes trying to catch the stuff with my little minion, just off Karl Marx Straße. It’s so light it responds almost like magnetism when you rush to grab it, flipping up and away out of grasp. It’s also worth investigating the little flower buds that release the flower seeds. The compress a tremendous amount in a small space. If you make a cut in the bud/pod they almost erupt out like furry puss.
Being new to Berlin and still curious about such everyday Berliner details, I brought some home to identify it. Using the app LeafSnap, I discovered it was Populus nigra / Black Poplar / Schwarz-Pappel. And with your post, I realise I’m not the only one who thinks it noteworthy. Thanks.
Imaging having to catch enough of them to fill a blanket! I think most of the poplar trees in Berlin are Black Poplar, though I couldnt find a source to confirm. Even after almost a decade in Berlin, I still love following up on these little things 😉
How long have you been in Berlin now?
In case this could help someone in the future. This stuff is EXTREMELY FLAMMABLE. I accidentally set fire to a campsite because of this stuff; it was unbelievable how fast fire can spread through a carpet of it. EXTREM VORSICHT!!
oh yes, this stuff is super dangerous when it comes to flames. Quite a few forrest fires have started because people carelessly threw out cigarettes and set this stuff on fire.