Saponaria officinalis Rosea Plena

The Saponaria officinalis 'Rosea Plena', known as the double-flowered soapwort, soapwort, or soap herb, is a very robust perennial with a quaint charm, ideal for an informal garden. It blooms for a long time in summer, adorned with lovely campanulate flowers in a soft pink colour and slightly fragrant. It forms a dense clump, and can even become invasive when it thrives in moist soil. Its foliage is glabrous and a bright green. Although not dazzling, it is a fairly undemanding, graceful, very robust and long-lived plant. It will thrive in full sun, in a natural garden or a country flower bed.

The Saponaria officinalis is a herbaceous perennial plant of the Caryophyllaceae family, native to Europe and Asia, formerly cultivated in Mediterranean gardens. This wild plant is frequently found in the countryside, along paths and near watercourses. The 'Rosea Plena' variety, from which it originates, distinguishes itself with its semi-double flowers. The plant, equipped with very running rhizomes, forms loose clumps that spread over time, particularly in rich and moist soil. This plant will reach a height of about 60 cm (24in), with a minimum width of 50 cm (20in). The upright and spreading stems bear flowers resembling those of phlox, but semi-double in light pink, slightly fragrant, and gathered in dense clusters above the foliage from July to September. Its leaves are opposite on the stem, ovate, bright green, pointed, and deeply marked by 3 longitudinal veins.

The double-flowered soapwort has a striking effect when planted in large colonies in a garden that allows space for nature, but is not recommended for small spaces. It can be associated with pretty wildflowers, such as Galega officinalis, Campanula pyramidalis, mulleins, centaureas, artemisias, cornflowers, fennel or viper's bugloss. It will also thrive in the company of other plants that are equally resilient, such as Persicaria, Ligularia, Lythrum, Veronicastrum. Also note that shade will stop this plant's growth as effectively as weedkiller.