Garden Features

Rock Garden

The original Rock Garden was built in 1882 and designed to resemble a Pyrenean mountain valley. The rocks were replaced with Sussex sandstone that can hold far more water than the original limestone.

The half-hectare site has been recently redesigned to include a central bog garden and cascade. Moist gullies, water features and other special environments allow for the cultivation of a variety of plants, mainly alpines, Mediterranean and woodland / moisture-loving plants.

Alpine plants: grow in exposed rocky positions, and are used to plenty of sun. In the winter, they lie under a blanket of snow that protects them from extremes in air temperature, and are kept dry because the water is frozen. In Britain the winters are relatively mild and wet so they need a well-drained soil and a mulch of grit to keep moisture away from the leaves.

Mediterranean plants: five areas of the world have a Mediterranean type climate (California, the southern tip of South Africa, central Chile, south-west Australia, and the Mediterranean region itself). The plants are used to mild, wet winters and hot, dry summers with plenty of sun. The Rock Garden provides a sunny position and a well-drained soil that prevents the plants getting too much moisture in our relatively wet summers.

Woodland and moisture-loving plants: grow on the lower slopes of mountain ranges. Here the melting snow creates streams and waterfalls often lined with moisture-loving and woodland plants. In the Rock Garden, these conditions are created with a system of water features and a few shady gullies, particularly in the Asian, British Native and North American sections.

There are 2,648 plant accessions in the Rock Garden, in which plants from all over the world are cultivated. The Rock Garden is arranged in six geographical areas to display this diversity:

Europe: This is the largest section, and contains British native plants from different habitats, including:

• mountainous, e.g. Purple Saxifrage (Saxifraga oppositifolia).

• rocky habitat, e.g. Cheddar Pink, (Dianthus gratianopolitanus).

• woodland, e.g. Lords and Ladies or Cuckoo Pint (Arum maculatum).

It also has a section which contains plants from mountainous areas of Europe, including the Alps and Pyrennees. The alpine plants grown include bulbs such as Crocuses and the Summer Snowflake (Leucojum aestivum).

Africa and the Mediterranean: This mainly represents the flora of the Mediterranean region, but includes several plants from South Africa that grow outside at Kew. The Mediterranean plants are from a variety of habitats such as hot and dry regions (southern Spain), high ground (Atlas Mountains) and rocky river gorges (Crete).

Asia: The Asian section features many alpine plants from the Himalayas, Caucasus and China, such as the hardy Ginger species (Roscoeas). Three waterfalls lead into the stream where moisture-loving plants such as Siberian Irises (e.g. Iris siberica) are grown.

Australia and New Zealand: The majority of alpines and shrubs from Australia and New Zealand require moisture during the summer months. The soil used here contains coconut fibre (coir) and composted bark that hold water well and therefore reduce plant losses in summer. The alpine plants come from the Southern Alps of New Zealand and those favouring a Mediterranean style climate come from south-west Australia.

South America: Alpine plants from the Andes Mountains and Patagonia include species of the Peruvian Lily (Alstromeria). South America sages (Salvia spp.) come from central Chile, which has a Mediterranean-type climate.

North America: This area features a large waterfall that cascades into a pool surrounded by boggy ground to suit moisture-loving plants such as the Cardinal Flower (Lobelia cardinalis). The alpine plants come from the Rocky Mountains and the Appalachian Mountains. The coastal strip of California has a Mediterranean climate with plants such as the low-growing Californian Lilac (Ceonothus prostratus).

The Rock Garden is number 36 on the Visitor Map.