Medicago arborea

Is your nitrogen broken? Time to call in this nitrogen-fixer! This unique, easily grown and drought tolerant deciduous shrub is native to Southern Europe and especially the Mediterranean Basin. Soft textured trifoliate leaves on long stems are decorated with long terminal spikes of showy yellow pea-ish flowers that cover the plant in spring. If it's really happy it might get 6' tall or more but it is easily kept smaller. As a legume family member it also fixes nitrogen, but it has never set a single seed for us. In the wild it's summer deciduous, retaining leaves in the winter, but it seems to at least partially reverse its growth cycle for us, having more leaves in summer and sometimes dropping them (but never with stem damage) for part of winter if the weather gets too cold. So far we haven't ever had cold damage on it: it's certainly hardy to 10 °F, and perhaps to 0 °F or even lower.