The Mary Mullins Forest House, as the fern unit is called, is in the north-west corner of the conservatory. It is kept permanently shaded but warm and humid to create a forest atmosphere with plants from the warmer subtropical parts of South Africa. It includes a wonderful selection of ferns as well as forest succulent species such as Rhipsalis, Plectranthus, Peperomia and Gerrardanthus. Look out for the beautiful Streptocarpus, close relatives of the African violets (Saintpaulias).

Other plants in this section include the trees Morus mesozygia, Ficus trichopoda, the tree Fuchsia (Halleria lucida) and wild plum (Harpephyllum caffrum).

Typical ferns grown here include Alsophila dregei, A. capensis, Rumohra adiantiformis Nepholepis biserrata, Microsorum punctatum, Blechnum attenuatum, and Asplenium rutifolium. Stenochlaena tenuifolia is a beautiful fern creeping up the stems of trees.

Other forest plants are: Plectranthus oertendahlii, Crassula inandensis, Begonia dregei, B. homonyma, B. sutherlandii etc. Schoenoplectus lanceum and many Streptocarpus species, Peperomia blanda, P. rotundifolia. P. tetraphylla & P. retusa, Gerbera cordifolia, Dracaena hookeriana, Dermatobotrys saundersiae, Pterogramma and Impatiens duthieae.

Hanneke Jamieson is responsible for this section and David Davidson's expert landscaping is evident here.