Salvia uliginosa African Skies - Sauge des marais, Sauge uligineuse

 The Salvia uliginosa 'African Skies', known as the marsh sage or uliginous sage, is distinguished by its supple and highly branched stems, covered in late summer with small flowers of a particularly pure sky blue. This tall, airy perennial attracts bees and butterflies until the first cold spells. It is invaluable for bringing life to a large border in moist soil or for planting around a pond in climates that are not too cold. However, its running habit will need to be monitored.

This sage belongs to the Lamiaceae family. The name African Skies is used commercially for the species Salvia uliginosa, but it does not designate a cultivar whose own characteristics are truly established. It is a herbaceous perennial: all its above-ground growth dies back in winter, and its rootstock sends up new shoots in spring. It starts into growth quite late, sometimes only in May. The botanical species Salvia uliginosa grows naturally in marshy meadows and other damp habitats from southern and south-eastern Brazil to northern Argentina. The epithet uliginosa comes from a Latin word evoking marshy ground. The plant has a rhizomatous rootstock from which arise numerous erect, slender, quadrangular and branched stems. At maturity, the plant reaches 1.30 to 1.60 m in height with an 80 to 90 cm spread. In moist soil, its rhizomes spread rapidly and the clump can widen considerably further. In moist soil, the rhizomes gain ground and the clump can spread well beyond. The leaves, arranged in pairs along the stems, are narrow, lanceolate and coarsely toothed. Measuring 5 to 10 cm long, they are medium green, slightly sticky and give off an aromatic scent when crushed. Flowering occurs from August to October, or even into November if the autumn is mild. The branch tips bear short spikes of two-lipped flowers 1.5 to 2 cm long, of a luminous azure blue, with a whitish throat and fine markings that guide insects towards the nectar. The hardiness of this variety reaches –12 °C once the rootstock is well established and protected by a mulch. 

As this sage tends to spread in moist soil, it is best paired with robust, tall perennials capable of holding their own against it. Its cloudy blue flowering blends beautifully with the purplish pink of Eupatorium maculatum 'Atropurpureum', the deep pink of Filipendula rubra 'Venusta', the burgundy of Persicaria amplexicaulis 'Blackfield' and the violet of Vernonia crinita 'Mammuth'. All enjoy sun and proximity to water. Their vigorous growth and late flowering create a natural, colourful display in a spot where the plants can develop freely.