Caragana arborescens

Caragana arborescens is also known as the Yellow Acacia due to the appearance of its foliage and yellow flowering, modestly reminiscent of acacias. It is also called the Siberian pea tree, in reference to its Mongolian origins. It is difficult to find a more robust and frugal bush that can withstand harsh conditions, although it may not be the most spectacular. Thriving in a cottage-style flower bed, alongside lilacs and romantic roses, it is a valuable ally for those who garden in barren or limestone-rich soils, surrounded by vitex, Afghan sage, coronillas, and other low-maintenance plants.

Caragana arborescens belongs to the Fabaceae family, and is native to Siberia and Mongolia, where it is often planted as a hedge to protect orchards from wind and unwanted visitors. Hardy well beyond -20°C (-4 °F), this plant tolerates a wide range of soils, from slightly acidic to very calcareous, even poor ones, but it dislikes waterlogged soils. Its deep root system allows it to withstand drought once the bush is well established.

It is a fast-growing deciduous bush, composed of multiple stems, but it can also form a small tree with low branches. Often wider than it is tall, it reaches an average size of 4.5 to 5m (15 to 17ft) in all directions. It has a naturally flexible and rounded habit, supported by thin slightly trailing branches. Its dense and fresh light green foliage is made up of leaves divided into 5 to 7 pairs of small ovate and villous leaflets, about 2cm (1in) long, with small spines. They turn yellow in autumn before falling. The flowering takes place from April to May. Short clusters of light-yellow pea-like flowers open here and there among the foliage, on the previous year's wood. This honey-scented flowering is followed by the formation of 5cm (2in) long pods, each containing 4 to 6 seeds. The young pods, peas, and flowers are edible.

Caragana arborescens is not a spectacular plant nor does it have an exotic appearance, but it can adapt to difficult conditions, including very severe frost. It is valuable for gardens where the soil lacks depth, and for soils degraded by construction work in a brand-new garden. It can be planted in an informal hedge, alongside Coronilla glauca, cotinus, Lonicera tartarica, Sophora davidii, buddleias, Phillyrea angustifolia, or even Rhamnus alaternus 'Argenteovariegata' (in not too cold climates). All these low-maintenance shrubs are perfect for adding a touch of whimsy to neglected areas of the garden. For example, you can plant small shrubs like cistus, lavender, helianthemums, or bushy sage with summer flowering (Salvia 'Royal Bumble', S. 'Rêve Rouge', S. 'Raspberry Royal') next to it, in a sunny spot.