About the Garden Plant collections Pond Rockery The Pond Rockery is Europe's oldest rockery and has a fascinating history. It supports a range of Mediterranean and alpine plants. The Garden's unique micro-climate is well suited to many of these species. Winters rarely dip below -1C and we have an annual rainfall of 600mm. In 2014, a new rock garden was added around the Rockery to allow more space for growing Mediterranean species. You'll spot a bust of the famous plant hunter Joseph Banks at the front of Pond Rockery, overlooking the basalt he used as ballast on the ship St Lawrence when he sailed it to Iceland in search of new plants. There are also fused bricks from a brick kiln in Chelsea and clam shells from a voyage to Tahiti with Captain Cook, plus pieces of masonry from the Tower of London- an eclectic mix! The pond itself is home to some aquatic plants. The central island houses examples of the carnivorous genus Sarracenia. These pitcher plants enjoy the humid, boggy, acid conditions provided on the pond island.