The mild temperatures have unpleasant side effects for allergy sufferers: the hazelnut has been blooming in some places since December, the alder is in the starting blocks. “This is no longer unusual,” said agricultural meteorologist Wolfgang Janssen from the German Weather Service in Offenbach, referring to climate change.
If it stays mild for the next few weeks – and that’s what it looks like – all the hazelnut bushes will be in bloom as early as January 25th and distribute plenty of pollen. The average day for this has been February 10 since the 1990s, before that it was only February 25 on average.
In this and the previous winter, nine percent of the hazelnut bushes were already in flower at the end of December – such a quota would not normally be until two weeks later. “In 2016, the proportion was even nine percent on December 15,” says the meteorologist.
The alder is far from that far, its flowering percentage is currently only one percent, as it was also said. However, on a long-term average, it only begins to distribute its pollen at the beginning of March. Here and there snowdrops are already peeking out of the ground, and their share is therefore one percent. According to Janssen, they usually bloom on average from around February 17th.
