Wisteria frutescens 'Amethyst Falls' is a daintier, better behaved version of the Chinese wisteria for small spaces.

Gordonia grandiflora is a remarkable semi-evergreen tree with lancolate leaves and fragrant, camellia-like flowers.

Yucca filamentosa 'Excalibur' forms rosettes of spiky, strap-like leaves coloured blue-green to powdery blue.

Yucca rigida is a dramatic, trunk-forming, hardy species with a crown of stiff, sword-like, powder blue leaves.

Zantedeschia 'Albomaculata' is a spotted calla lily with ivory-white trumpet-shaped flowers.

Zantedeschia 'Creme/Cream' is a spotted calla lily with creamy white and green flowers.

Zantedeschia 'Dubai Nights' is a stunning velvety purple calla lily with white edging to each spathe.

Zantedeschia 'Flame' is a spotted calla lily that displays bi-colours of yellow and orange-red.

Zantedeschia 'Garnet Glow' is a spotted calla lily with rosy-pink, trumpet-shaped flowers.

Zantedeschia 'Majestic Red' displays dark red trumpet-shaped flowers with black bases.

Zantedeschia 'Millenium Gold' is a spotted calla lily with bright yellow trumpet-shaped flowers with green bases.

Zantedeschia 'Pasja' is a calla lily with flowers that open purple and lighten towards shades of pink.

Zinnia grandiflora 'Gold on Blue' is hardy to zone 4 with fine, textured, bluish-green foliage topped with golden yellow flowers all summer.