Chelone glabra linifolia

An upright perennial with narrow leaves and slightly green-tinged white flowers – very fresh and elegant in the autumn border. 

Any retentive soil in sun or part shade. 
£8

Berberis calliantha

The spiny edged foliage is glossy green above and white underneath and the flowers are lemon yellow – nothing unusual about any of that - except that the leaves and flowers are bigger than any similar species – the leaves up to 2ins long and the flowers an inch across, and all this on a low compact shrub not more than 3ft tall. At the same time this is as hardy and adaptable as any of the more familiar types. 

Many people dismiss Berberis as just a lot of dull scruffy spikey shrubs, too often planted around carparks (and full of litter) but there are quite a few good, interesting species for the more discerning gardener – and calliantha is one.  
£16

Weigela middendorffiana

An interesting alternative to the commoner Weigelas in cultivation, having soft yellow flowers in early summer developing orange markings inside. 

More compact than the others too at about 6ft x 6ft and may be pruned quite hard after flowering. Any situation except very dry, very wet or very shady.
£16

Teucrium fruticans Azureum

A form of this popular shrub with intense blue flowers over a long period in spring and summer. The foliage is a cleaner combination of white and green than the more common form. 

Better in every way in my opinion.

Ideal for a hot sunny site on well-drained soil, with shelter from cold winds.
£12

Silene regia

An amazing tall upright N.American species with big, intense red flowers over a long period. 

Hardy and long-lived
£6

Schisandra grandiflora

A strong deciduous woody climber grown for its nodding creamy Gardenia-scented flowers up to an inch across. 

Easy in woodland conditions.
£16

Saruma henryi

A peculiar relative of the Asarums in that it has more conventional yellow flowers in spring. The emerging foliage is soft suede and dark tinged and a feature in its own right. 

The mature foliage reminds me a bit of Brunnera. An adaptable woodland or border plant.
£8