The Ian Reddihough Mountain House, more commonly known as the Alpine house, contains plants (herbaceous, geophytic and succulent) from high altitude regions in South Africa. The soil and air in here is specially cooled to between 10 and 18°C. It is also ecologically divided into high veld and mountain regions with plants from the Soutpansberg in the north to the Cederberg in the west. Rocks from the same regions have also been introduced.

Mountain ranges are mainly situated on the south and eastern escarpments of South Africa and are highest in Lesotho ( about 3 000m). These eastern mountain ranges receive summer rain and fall into the Grassland biome, unlike the mountains in the south western regions which have a winter rainfall and support fynbos. The fynbos mountain vegetation of the western regions is kept moist in summer by the cool clouds brought by the south-east winds.Winters can be very cold with severe frosts and occasional snow, particularly on the eastern escarpment.

The plants in this section are arranged ecologically and according to their distribution. Many alpines from Lesotho grasslands have also been introduced, including the spiral aloe (Aloe polyphylla). Look out for Euphorbia clavarioides which resembles an anthill - its compact growth is typical of alpine plants.

Alpines from the Western Cape which can be found here include; Aloe haemanthifolia, Bulbine lagopus, Hymenolepis speciosa, Ornithogalum maculatum, Senecio serpens, Pelargonium ovale, Erica nana, E. equisetifolia, Felicia cymbalariae, Euryops othonnoides, Agathosma serphyllacea, Sutera violacea, Nemesia diffusa, Nivenia stokoei, Stilbe albiflora, Cliffortia dentata, Oldenburgia paradoxa, Erepsia mutablis, Esterhuysenia alpina, Oscularia deltoides, Antimima pygmaea.

Summer rainfall alpines grown here include: Aloe aristata, Helichrysum chionisphaericum, Gasteria excelsa, Eucomis autumnalis. Aloe inyangensis, A. nubigena, A. pratensis, A. thompsoniae, Crassula pellucida subsp. pellucida, Senecio speciosus, Craterocapsa sp. Craterostigma wilmsii, Thorncroftia media, T. thorncroftii, T. longiflora, Bulbine narcissifolia, Crassula setulosa, C. sarcocaulis, C. natalensis, Dianthus basuticus, Delosperma ashtonii, Khadia borealis, K. acutipetala, Haemanthus montanus, H. hirsutus, Cyrtanthus junodii, Drimia robusta, Ledebouria sp., Euphorbia clavarioides var. truncata, Delosperma obtusum, Rhodohypoxis baurii.

Norma Jodamus is the horticulturist responsible for this section.