The small, white, two-lipped flowers of Coleus gibbosus with their slightly sigmoid (S-shaped) corolla tubes are adapted for insect pollination. The pollinator is a megachilinid bee, Chalicodoma sp. which Potgieter and Edwards observed visiting the flowers in Leopard’s Bush Nature Reserve during their study. Honey bees (Apis mellifera) and the bee Allodape pernix were also observed visiting the flowers but only to collect pollen. Although only bees were observed to visit the flowers, various flies and other nectar-feeding insects may also visit the flowers. The curved flower tube only allows certain insects to access the nectar and while feeding they are positioned where they will transfer pollen between the flowers and effect pollination.

Growing naturally along forest margins and in scrub vegetation, C. gibbosus is well adapted to partially shaded environments. Its dense foliage provides ground cover and contributes to the understorey vegetation, helping to protect the soil from erosion and retain moisture. Like many members of the mint family (Lamiaceae), the species is vigorous and readily regenerates after disturbance. Stems that come into contact with the soil may produce roots, allowing the plant to spread vegetatively and recover from grazing, trampling or other physical damage.