Calobota cytisoides has a more southern distribution than the closely related C. sericea (Thunb.) Boatwr. & B.-E.van Wyk and has been collected at altitudes of between 20 m and 1000 m in fynbos and renosterveld vegetation on sandstone, shale, well-drained sand and clay. It is often found on western, southern or south-western slopes, along rivers or in riverbeds and also along disturbed roadsides. Rebelo et al. (2006) and Mucina et al. (2006) list this species as an important component of Shale Fynbos, Shale Renosterveld and Rainshadow Valley Karoo.

The flowers of Calobota cytisoides have a very sweet scent. The nectar of this species and the rest of Calobota is generally sucrose-rich (Van Wyk 1993), which is typical of most bee-pollinated legumes. The potential pollinators of some of the Cape genera of the Crotalarieae were studied by Gess & Gess (1994, 2003). They found that the flowers of Calobota species were visited by solitary aculeate Hymenoptera (bees or wasps), specifically Masarinae and Megachilinae of the tribes Megachilini and Anthidiini and also some species of Xylocopinae.