Boronia heterophylla

Boronia heterophylla, the Red Boronia, is a highly floriferous and aromatic bush that will delight exotic plant enthusiasts. From a distance, in spring and summer, it somewhat resembles a heather shrub, with its upright, ramified habit, delicate foliage, and small pendulous bell-shaped flowers in a vibrant magenta pink. Like heather, it prefers slightly acidic soil, but the comparison stops there. It is a plant related to citrus trees, not very hardy, and thrives in soils that retain moisture in summer. If you have a garden located in a mild coastal region then this Boronia should thrive in your garden. As it performs very well in pots, gardeners in more colder climates can enjoy it on the terrace throughout the summer, pick its flowers to create delightful scented bouquets, and bring it indoors during winter in a lightly heated greenhouse or conservatory.

Boronia heterophylla is a bush from the Rutaceae family, native to the extreme south of Western Australia. Among the hundred species belonging to the genus Boronia, it is undoubtedly the one best adapted to cool climates. Its species name, heterophylla, refers to its small leaves with variable appearances, sometimes entire, sometimes finely dissected. It grows fairly quickly, reaching its adult size in 3 years, with an upright and generally oval habit, averaging 1.20m (3ft 11in) in height and 1m (3ft 4in) in width. It develops slender ascending branches, branching almost at every node along their entire length, almost parallel to each other. They bear narrow and pointed leaves of varying shapes, emitting a peppery scent when crushed. The particularly long flowering occurs in spring and summer. A multitude of flowers appears at the axils of the leaves, solitary or gathered in small groups. They are small pendulous bell-shaped flowers, 1cm (0.4in) in size, composed of 4 bright magenta pink petals with a waxy appearance. They are pleasantly fragrant. During fruit formation, the petals close and persist for a long time, enveloping the fruit until it ripens. This peculiarity gives the illusion of never-ending flowering.

Boronia heterophylla cannot withstand temperatures below -5/-6°C (23/21.2 °F), does not tolerate limestone or dry soils, and prefers full sun. Its requirements are clear and must be respected to succeed in its cultivation and enjoy its magnificent flowering. Outside of certain well-targeted areas of our Atlantic coast, it seems preferable to cultivate it in a pot, where the substrate and wintering conditions can be controlled. In the garden, it can be associated, for example, with Galvezia speciosa, Gomphostigma virgatum, broom shrubs, or white, pink, or red heather shrubs. On the terrace or balcony, it can be surrounded by Cape Leadwort, with its long blue flowering, Tibouchina, or Common Myrtle 'Flore Pleno'. Its spikes of small, intensely pink, fragrant flowers are a marvel in country-style bouquets!