Red-barked dogwood vs Red osier dogwood

In Central Europe hot, dry summers are what troubles it most: leaves scorch in prolonged drought, and a stressed shrub is more prone to leaf spot, twig blight and canker, and scale insects. Water in dry spells and cut diseased stems out at the base. Without regular renewal pruning the stems turn dull brown and the shrub becomes bare-legged and sprawling; sever root suckers with a spade if you do not want it to form a thicket.

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.