I went to Köln to visit the Botanischer Garten. It is a very rich garden (10 000 different plants are grown in the open air or under glasshouse) that can be visited all year. There is a very interesting collection of camellias, some of which is presented every year since 2001 in a greenhouse, from January 15 to April 15. Access is easy by metro from Central Station. The park and the exhibition are free.
Inside the greenhouse, you walk through a forest of camellias.
A yellow camellias in the collection. It is rare to see so many in one place.
Below, some Reticulata of the collection.
A part of the collection, in ground, can be found outside the exposition.