Hardy Ceanothus

A selection of hardy Ceanothus or Californian Lilacs, tolerant of temperatures as low as -15°C (5°F). Among the evergreens, Ceanothus 'Skylark' is considered the most cold-resistant. We are captivated by its intense blue flowering in spring, and its foliage remains attractive in winter. But it is the deciduous Ceanothus such as 'Gloire de Versailles' or 'Marie Simon' that thrive best in our fairly cold and humid regions in winter. With blue, pink, or white flowers, the spring or summer flowering of these bushes delights the gardener and feeds the bees. Ceanothus comes in many varieties. The evergreens, originating from California or Mexico, have a limited hardiness of -7°C (19.4°F) or -10°C (14°F), or even -12°C (10.4°F) for the prostrate Ceanothus, Ceanothus prostratus or the compact variety 'Italian Skies'. In any case, the cold resistance of Ceanothus depends on the growing conditions. Deciduous species tolerate brief frosts in well-drained soil. They prefer deep, moist, and humus-rich soil.