Common dogwood vs Red osier dogwood

Its spread is the main problem: with root suckers it builds a dense thicket within a few years and runs into neighbouring beds and lawn. Only young stems are coloured and old branches turn grey-green, so it needs regular renewal pruning for the winter effect. The coloured-stem cultivars are smaller and weaker growing than the species. It prefers evenly moist soil and grows more weakly in prolonged drought. It has few diseases: leaf spot or anthracnose on weak shoots and occasionally scale insects. The flowers smell unpleasant.

It spreads fast by underground stems and layering branches, and after escaping from gardens it has naturalised in several parts of Central Europe, where it can form dense single-species stands in cool, damp habitats, along watercourses and at woodland edges. Its sale is banned in Switzerland and it is on the watch list in Luxembourg, so do not plant it near natural banks, wetlands or woodland edges and do not dump prunings outdoors. Stressed plants in hot, dry sites often get stem canker, leaf spot and twig blight; scale insects and leaf miners also occur.