Bee flies act as the pollinator of the unusual pea-like flowers. The seeds of pelargoniums are interesting as they have narrow, brown heads with spiral tails and are light in weight. This tail causes the seed to twist around in the wind and it drills itself into the soil in a corkscrew fashion, ensuring that most of the seeds produced, have a good chance of germinating.

The leaves and flower stalks are hairy, this is an adaptation that reflects the sun and slows air movement over these areas, which reduces water-loss. Normally tubers of this species grow underground; however, they may be exposed occasionally when seedlings manage to take root in very rocky terrain. In such cases, the tubers are protected from drying out by numerous flaking periderms.

Porcupines often eat the tubers. The colony of the bergpatat near De Rust, is controlled by molerats which consume large numbers of tubers after rainfall, whereas the molehills provide beds of soft soil in which Pelargonium rapaceum seeds can germinate and some parts of the tuber left can resprout.

The colony of the bergpatat near Citrusdal is exposed to periodic fynbos fires. The fire clears the area of bushy shrubs and the ash after fire, creates ideal conditions for seeds to germinate. On the other hand, partially exposed large tubers with dry massed old petioles, ignite readily in the fires and are destroyed reducing the population.