Sorbus Autumn Spire 'Flanrock' (Mountain Ash) is a small upright tree with vibrant green leaves that mature to purple, red and yellow in the autumn months. The vivid autumnal leaves contrast beautifully with the bright yellow berries that this mountain ash sprouts. Pretty white flowers also develop in spring. In 10 years of growth, 'Autumn Spire' Mountain Ash trees have a height of 4 metres and a spread of 1 metre. They are suited to all soil types and require a position in full sun.