'Violet Stardust' is a bush clematis with violet-blue, star-shaped flowers followed by pretty seed heads.

Clematis 'Walter Pennell' is a unique cultivar in both colour and form with interesting shades of pink on semi-double flowers.

Clematis 'Warsaw Nike' has rich velvet purple flowers illuminated with a magenta glow around yellow stamens.

Clematis 'Will Barron' has beautiful clear blue flowers with lighter central bands around yellow stamens.

Clematis 'Will Goodwin' has beautiful ruffled lavender-blue flowers with cream coloured stamens.

Clethra alnifolia 'Hummingbird' is a compact shrub with white bottlebrush flowers that are fragrant and nectar-rich.

Clethra alnifolia 'Ruby Spice' is a compact shrub with pink and white bottlebrush flowers that are fragrant and nectar-rich.

Clethra alnifolia 'Summer Sparkler' is a compact shrub with long, twisting racemes of white flowers that are fragrant and nectar-rich.

Blue mistflower (Conoclinium coelestinum) has flat-topped clusters of fuzzy, lavender buttons on purplish stems in summer and fall.

Coreopsis 'Gilded Lace' has fine, linear foliage on four feet tall stems topped with hundreds of cheerful, bright yellow, daisy-like flowers in summer.

Coreopsis tripteris is a 6 foot high tickseed producing masses of bright yellow flowers from summer to fall.

Coreopsis tripteris 'Gold Standard' is a 6 foot high tickseed producing masses of bright yellow flowers from summer to fall.

Coreopsis Big Bang 'Sun Splash' has all summer-long fiery flowers of bright red with golden tips.

Coreopsis Lil Bang 'Darling Clementine' has large flowers in tones of deep orange, tangerine orange, and golden yellow.

Coreopsis Lil Bang 'Enchanted Red' has large, deep red flowers with yellow centres surrounded by a dark ring that will bloom all summer long.

Coreopsis Lil Bang 'Starstruck' has big, two-tone petals of magenta and light pink all summer long.

Coreopsis Permathread 'Shades of Rose' is a tickseed with varying shades of pink around yellow centres.

Cornus elliptica Empress of China is a gem of an evergreen tree with copious pointed white flowers and purple winter foliage.

Cornus florida Cherokee Brave has incredible glowing deepest pink to red blossoms. One of the best of all flowering dogwoods.

Cornus florida Cherokee Brave has incredible glowing deepest pink to red blossoms. One of the best of all flowering dogwoods.

Ragin' Red has the darkest red flowers of any Cornus florida plus the most amazing burgundy foliage.

Cornus kousa 'Snow Tower' is a compact dogwood with masses of single white flowers and striking fall colour.

Cornus kousa 'Snow Tower' is a compact dogwood with masses of single white flowers and striking fall colour.

Cornus kousa 'Snow Tower' is a compact dogwood with masses of single white flowers and striking fall colour.