Pelargonium tomentosum is an aromatic, low-growing, sprawling subshrub, with branches spreading in all directions. It can grow up to 0.5 m high and has a spread of 1.5 m.

Pelargonium tomentosum is confined to mountains where it occurs naturally in semi-shaded, moist habitats, on the margins of ravine forests, near streams. It grows in sandy soil derived from sandstone. This species is found in frost free habitats.

Pelargonium tomentosum is an attractive garden plant. It can be used as a ground cover in semi-shady, moist areas, providing that the soil drains well. It can also be used on embankments in semi-shaded areas or grown in pots.

Owing to its broad, coarse leaf texture, the peppermint pelargonium can provide a wonderful contrast against the fine-textured foliage of other species. Use it in light shade for group plantings, interplantings or in a fragrance garden. It is particularly useful in a fynbos garden. It also does well in containers.

Its leaves are large, velvety and mint-scented. The leaves are simple, cordate at the base and vary from 3–5-palmatilobate, to 3–5-palmatipartite. The presence of soft hairs and numerous glandular hairs lends a velvety touch to the leaves and stems. The leaves are showy, especially when covered with morning dew.

The species name tomentosum, means ‘densely hairy’ and refers to the leaves, which are thickly and evenly covered, on both surfaces, with short, curved, matted hairs.

The peppermint-scented leaves can be used as a culinary herb.

Small, white flowers with purple markings on the petals, are borne in much-branched inflorescences of 4–15 flowers, from spring to midsummer (October to January).