Achimenes 'Snow Princess' is an orchid pansy related to the African Violet with delicate snow white blooms and tiny purple throats.

Actaea japonica 'Silver Blush' has has wands of creamy-white bottle brush flowers and serrated silver foliage maturing to green.

Actaea japonica 'Silver Dance' has wands of creamy-white bottle brush flowers and silver foliage maturing to green.

Actinidia kolomikta 'Emerald' is much loved for its unusually large, sweet and flavourful fruit.

Actinidia pilosula has luscious foliage that is burgundy when young and later deep green tipped with white.

Adiantum pedatum, the northern Maidenhair fern, is one of the most beautiful of all ferns with distinctive palmate fronds.

Adiantum raddianum 'Fragrantissimum' is an evergreen maidenhair fern with arching black stems and light green aromatic fronds.

Aeonium aureum (syn. Greenovia aurea) ex. El Hierro is a large form of the green rose buds with blue-green leaves.

Likely Aeonium (Greenovia) dodrantale forming multi-branching colonies of small rose buds.

Bottlebrush buckeye, Aesculus parviflora, is topped with dramatic summer spires up to 12 inches high of tubular white flowers.

Aframomum melegueta or grains of paradise is a tropical ginger grown for its pepper-flavoured seeds.

Agapanthus Fireworks is a striking lily-of-the-Nile with bicolour flowers of violet blue and white.

Agapanthus 'Northern Star' has gorgeous bicolour flowers of dark blue with dark violet stripes down the middle of each petal.

Agapanthus 'Poppin' Purple' is a compact, fast-growing lily-of-the-Nile with violet purple flowers.

Agapanthus 'Summer Love Blue' has fragrant violet-blue flowers on strong green stems and green, strap-like foliage.

Agapanthus 'Valencia' offers sky blue flowers with darker veins and reverses on dark stems.

Agastache cana 'Double Bubble Mint' is a Texas hummingbird mint with fragrant magenta coloured flowers and aromatic foliage.

Agastache 'Blue Bayou' is a long-blooming hummingbird mint with blue tubular flowers and aromatic foliage.

'Crazy Fortune' is a sport of Agastache 'Blue Fortune' with lavender blue flowers and variegated foliage.

Agastache 'Danish Delight' is an anise hyssop with vibrant hot pink to reddish-purple blooms and fragrant green foliage.

Agastache 'Guava Lava' is a hummingbird mint with coral-orange flowers and mauve-pink calyxes.

Agastache 'Pink Pearl' is a stunning hummingbird mint with dense spikes of mid pink buds opening to glowing light pink flowers.

Agastache Sunrise 'Blue' is a long-blooming hummingbird mint with violet-blue tubular flowers and fragrant foliage.

Agastache Sunrise 'Rose' is a long-blooming hummingbird mint offering a beautiful display of tubular pink flowers.

Agave angustifolia var. letonae has long, sword-like leaves in shades of green to grey-green and can develop nice trunks.