How Not to Overwater a Rheophyte: Successful Cultivation of 'Difficult' Tropical Rainforest Plants Using Inorganic Compost media

Abstract

Many herbaceous plants native to Malesian perhumid tropical forests are difficult to cultivate long term in traditional (peat, coir and bark) compost mixes. As a result, many appear to be underrepresented in ex situ living plant collections. Under the leaf-litter, lowland rainforest soils are typically surprisingly low in organic content (< 2%) and many of the smaller forest-floor-dwelling plants exist mainly on steep slopes of bare mineral soils with limited leaf-litter cover. By adopting purely inorganic compost media and placing pots in trays of water the wet mineral soils of their natural habitats are replicated and the plants can be cultivated long term with notable ease. The use of wholly inorganic media reduces the incidence of root rot to such an extent that it is suggested that they should be used more often for the cultivation of slow-growing taxa from other regions which are often considered to be ‘difficult’.