Many exotic shrubs have successfully naturalised following their introduction for ornamental reasons. The most common species are:

Rhododendron ponticum is an evergreen shrub which grows exceptionally vigorously in the climate of Western Britain, it was introduced as an ornamental because of its foliage and beautiful flowers. It has trouble establishing from seed, but by spreading from offsets it can completely take over native woodlands on acid soils. In the Midlands it is less invasive, but can it still be a problem in some semi-natural woodlands. Other species of Rhododendron can establish themselves in the wild, but they are usually less invasive.

The cherry laurel (Prunus laurocerasus) is superficially similar to Rhododendron, but it has less striking, green flowers, followed by black, cherry-like berries. Again it was introduced by landscapers for its year round evergreen foliage. It is this dense cover which shades out other plants which can cause a problem in some woodlands. The Portugese laurel is another similar species.

Snowberry (Symphoricarpus albus) and Oregon grape (Mahonia aquifolium) are small shrubs which can spread rapidly into semi-natural woodland, forming dense, low thickets. This mode of growth makes them popular with landscapers, but means that in a woodland they can exclude low growing plants. The snowberry has often been introduced to woods elsewhere in the past as cover for pheasants, and so may be a deliberate introduction in some woods on the urban fringe. which all readily colonise native woodland.

Other, less invasive, exotic shrubs include Spiraea salicifolia, Buddleja davidii, lilac (Syringia vulgaris) and Laburnum anagyroides. The first three of these are abundant nectar sources, while laburnum is heavily visited by larger bees. Buddleja is an important coloniser of previously built on land, and can often be found growing on old buildings.