Acaena saccaticupula 'Blue Haze' is an excellent ground cover with powder blue foliage.

Achillea ageratifolia is an unusual yarrow forming aromatic, silver-green, mounds covered in pure white daisies with light yellow centres.

Achillea filipendulina ‘Gold Plate’ is a yarrow that produces masses of large golden-yellow flowers on tall stems.

Achillea 'Apricot Delight' has large, flat-topped flower clusters in various shades of pink on strong stems up to 24 inches with fragrant, fern-like foliage.

Achillea Desert Eve 'Deep Rose' is a yarrow with dark pink flowers with yellow centres above fragrant, fern-like foliage.

Achillea Desert Eve 'Red Improved' has brick-red flowers above fragrant, fern-like foliage.

Achillea Desert Eve Terracotta has flowers in shades of yellow, orange and rusty orange.

Achillea millefolium 'Heartthrob' has large, flat-topped flower clusters with colourfast, velvet-red flowers above dissected, fern-like foliage.

Achillea millefolium 'New Vintage Red' has large, flat-topped flower clusters of bright red with white centres.

Achillea millefolium 'New Vintage Rose' has large, flat-topped flower clusters of rose pink with white eyes on strong stems to 24 inches.

Achillea millefolium 'New Vintage Violet' has large, flat-topped flower clusters of bright lavender pink with white centres.

Achillea 'Sassy Summer Taffy' has large, flat-topped flower clusters in shades of deep rose pink, salmon pink, light pink, and peachy pink on tall, strong stems to 32 inches

Achillea ptarmica 'Peter Cottontail' is a unique yarrow with white, button-like flowers held in low, cloud-like mounds.

Achlys triphylla is a unique ground cover attractive to pollinators and hummingbirds. The dried three-part leaves smell like vanilla.

Aconitum 'Cloudy' is a gorgeous bicolour monkshood with blue and white flowers.

The tall stems and purple-blue flowers of the monkshood Aconitum 'Arendsii' offer a substitute for Delphinium for shadier conditions.

Aconitum 'Royal Flush' has spires of purple-blue monkshood flowers preceded by luscious chocolate-red new growth.

Aconitum fischeri is a shorter monkshood to two feet with purple-blue flowers.

Japanese monkshood, Aconitum japonicum, has wonderful, hooded purple-blue flowers in summer on arching stems.

Aconitum lamarckii (syn. pyrenaicum) is an unusual monkshood with long airy racemes of pale sulphur yellow tubular flowers.

Aconitum napellus forms strong, vertical spires of purple-blue monkshood flowers.