Robinia pseudoacacia Casque Rouge - Black Locust

Robinia pseudoacacia (x margaretta) 'Casque Rouge' Flemor, also known as R. pseudoacacia 'Red Cascade' and R. x margaretta RED HELMET, is a beautiful deciduous tree of medium size, with an elegant airy growth habit and foliage that is both light and lush, turning golden yellow in autumn. This hybrid variety is appreciated for its brilliant late spring flowering, in the form of numerous slightly fragrant pendulous clusters, of a rich purple-pink. Delightful in spring, it will provide pleasant shade in summer and contribute to the autumnal splendour of the garden. This locust tree also owes its success to its ease of cultivation in any soil and in almost all climates.

This robinia is a horticultural hybrid obtained by cross-breeding Robinia pseudoacacia, native to the Eastern United States, and R. hispida, native to dry woodlands in the Southeastern United States. Belonging to the Fabaceae family, locust trees fix atmospheric nitrogen at their roots, allowing them to grow in poor soils. It is a long-lived tree with a columnar habit during the first years, and the sparse canopy becomes more rounded over time. With rapid growth, 'Casque Rouge' will reach an average height of 8 m (26 ft) with a spread of 4 m to 5 m (13.1 ft to 16.4 ft). The bark, initially smooth, develops an interesting fissured texture with age. Its strong branches bear a few thorns. The deciduous leaves, measuring 15 cm to 20 cm (5.9 in to 7.9 in), are divided into twenty bright green leaflets. They are highly decorative in spring, darken somewhat in summer, and turn yellow in autumn. The flowering takes place in May-June, on individuals about ten years old. The pendulous inflorescences, 10 cm to 20 cm (3.9 in to 7.9 in) long, are produced abundantly. They consist of dark purple-pink papilionaceous flowers that perfectly complement the light green foliage. This slightly fragrant flowering attracts pollinating insects. It is followed by the formation of reddish flat pods containing brown bean-shaped seeds. Note that this hybrid is more wind resistant than the typical Robinia pseudoacacia, whose branches are more brittle.

This robinia is suitable for both small and large gardens. Planted in isolation in a small garden, it also thrives on slopes or in free and defensive hedges in a large garden. It can be found as an ornamental tree along avenues. You can place it against a backdrop of evergreen shrubs or conifers (cypress, thuja, yew, juniper). It can also be planted alongside other low-maintenance and highly ornamental trees or shrubs such as Sophora davidii, Laburnum cytisus, Indigofera gerardiana. This locust tree also owes its success to its ease of cultivation in any soil and in almost all climates.