Caragana arborescens (= C. sibirica) (Sibiria)
Habit: Strong-growing large shrub, 3-5 m tall, 2-3 m wide, stiffly upright, losing its leaves from the bottom.
Flowers: Yellow butterfly flowers during or shortly after leaves shoot, May.
Leaves: Pinnate, light green to fresh green, green-yellow in October.
Roots: Shallow, main roots directly at the surface; collect nitrogen.
Demands: Sunny to lightly shady, tolerates heat, extremely frost hardy; good for urban environments, resistant to wind.
Soil: Dry to moist, not demanding, robust; poor, sandy-gravelly and loamy; slightly acidic to very alkaline; tolerates salt.
Native habitat: Caragana arborescens is a specialist. It grows in the steppes of northern China on stablized sand dunes alongside Pinus sylvestris, Ulmus pumila (the parent species of modern Ulmus hybrids) Crataegus, Rosa, numerous species of Artemisia, Allium, Papaver, Scabiosa, Sedum telephium, Thymus serpyllum and Veronica incana. In addition, there are grasses such as Festuca, Helictotrichon, Koeleria glauca and many species of Stipa.
Hardiness: Zone 3