Both royal women were rugged up for the occasion, with Princess Mary of Denmark looking stunning in a show-stopping blue coat.
The Australian born royal wore her hair in a half-up-half-down do' and accessorised her look with dangling pearl earrings and suede black heels.
Queen Margrethe of Denmark looked equally radiant in a white coat and black leather gloves.
The new panda plant will house two pandas named Xing Er and Mao Suni, which the Queen received as a gift from China's President at the state visit in 2012.
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