Oenothera speciosa Twilight - Evening Primrose

Oenothera speciosa 'Twilight' is a superb semi-evergreen ground cover, with large pale pink flowers from May to September. Hardy, it appreciates poor, rocky, neutral to alkaline, well-drained soils in full sun.

This evening primrose, also known as pink evening primrose, belongs to the Onagraceae family, which also includes fuchsias. Native to the southwest United States and Mexico, these rhizomatous plants grow in dry, rocky areas. The 'Twilight' evening primrose is therefore an excellent ground cover in dry terrain, for example to fill a slope or other rather unproductive areas of the garden. Its only requirement is a sunny, neutral to alkaline soil, but above all, perfectly drained, as its rhizomes can rot in case of excessive humidity. Poor soils do not scare it, and even in these conditions it will delight you with its very long flowering period from June to September, with large pale pink ephemeral cups with darker veins, adorned with yellow stamens. In addition, the flowers are fragrant and attract pollinators. This variety forms a carpet about 30cm (12in) wide and extends at least 50cm (20in). In cold weather, the semi-evergreen foliage of 'Twilight' takes on beautiful purple hues.

In favourable conditions, give it room to grow as it can then become very vigorous. It can also occasionally self-seed, but the young plants obtained may not necessarily have the characteristics of the parent plant. It can be grown in a pot, but it will probably require some watering during the hottest weeks.

Undemanding, the 'Twilight' evening primrose can be associated with plants that have similar characteristics, such as red Valerian (Centranthus ruber), Perovskia, Agastaches, or even rosemary (Rosmarinus officinalis) and its varieties. It will form a beautiful colourful carpet with all these neighbours, which are also floriferous and adapted to dry and hot soils.