The German naturalist Emil Adolf Rossmässler visted Barcelona in March 1856 on his study trip around Spain. Here he expalins why palm trees were still struggled in the city. Coming at the end of the so-called Little Ice Age temperatures were still too low.
Palm trees still do not trust Barcelona. On Palm Sunday I found thick ice in Pedralbes at midday in the shade of a house. [Elsewhere] in the botanical garden, a date palm struggled even though there was a protected corner. From “Recuerdos de un viajero por España de Emil Adolf Rossmassler”
See aslo The tallest palm tree in Barcelona