The horticultural value of Amelanchier is easily discovered in spring, with the appearance of its abundant racemes of five-petalled, star-shaped, white or pink-blushed flowers. These are followed by edible, spherical berries that are purple-maroon to black and similar to those of Sorbus, which ripen in June and are edible when cooked.
Belonging to the Rosaceae family, Amelanchier comprises single or multi-stemmed, deciduous trees and shrubs. It is a taxonomically diverse genus with no definite account of how many species it contains. Complexity arises because of the easy hybridisation of the genus and its ability to reproduce apomictically - that is, its seeds do not need to be fertilised.
Originally found in moist woodland and alongside streams and riverbanks, Amelanchier is native to regions of Europe, North America and Asia. A. lamarckii Award of Garden Merit (AGM) is one of the most commonly grown species and has become naturalised throughout Europe. It has an upright habit and can form either a shrub or small tree with brilliantly white flowers that are followed by plump berries. The elliptic, often coppery, dark green leaves turn to superb oranges and reds in the autumn.
Many of the species will provide striking interest, such as A. asiatica, which is sweetly scented. However, it is the many cultivars of this genus that provide displays throughout the year, with A. 'Ballerina' AGM featuring 15cm-long, arching, white racemes and A. 'La Paloma' displaying arching branches that carry colourful new growth and pure white flowers.
In addition to flower and colour, the genus offers form and structure, with A. x grandiflora 'Robin Hill' being compact and broadly upright, while A. alnifolia 'Obelisk' is, as its name suggests, fastigiate.
Amelanchier is fully hardy and prefers a deep, moist, humus-rich soil in sun or partial shade. With the exception of A. asiatica and A. alnifolia, which are lime-tolerant, plants prefer an acid to neutral soil.
Any pruning should be done during winter or late spring, when any misplaced or crossing shoots should be removed to maintain a healthy and balanced framework. Fireblight is a major threat to the genus, therefore any affected parts should be removed and destroyed. The genus propagates easily with softwood cuttings being taken when the new growth is no longer than 10cm.
Seeds can be sown fresh in the autumn or stored and sown in the spring to emerge the following spring - stratification can speed up this process. However, because hybridisation occurs readily, seed may not come true to type. New plants should flower within three to four years.
WHAT THE SPECIALISTS SAY
Nick Dunn, managing director, Frank P Matthews, Worcestershire "We stock a range of amelanchiers, including the basic species such as A. canadensis and A. lamarckii Award of Garden Merit (AGM) as well as newer and more interesting cultivars. These include A. 'La Paloma', with its pure white flowers and coppery young leaves, and A. laevis 'RJ Hilton', displaying an upright, well-balanced habit. Both of these have been very popular this year.
"Amelanchiers are good for moist sites, where they can be tolerant of heavy soils, but nearly all of them require an acid soil. Their main selling points are their early spring flowers, excellent autumn foliage and their suitability for smaller gardens.
"A. laevis 'Snowflakes' has sold well this year along with A. canadensis and A. 'La Paloma', and we are excited to have a new cultivar, A. canadensis Rainbow Pillar, which will be available from next year. Plants are produced in 12-litre and seven-litre pots and A. canadensis is available as a bare-root."
Keith Atkey, manager, Bridgemere Nurseries, Cheshire "Amelanchiers have proven to be good sellers because, having two seasons of interest, they provide good value for money. Spring blossom is accompanied by interesting bronzy foliage in some species and autumn produces stunning reds and oranges. They are available as single or multi-stemmed specimens with local authorities often using the lower-growing shrub types for roadside banking and screens.
"A. x grandiflora 'Ballerina' AGM, A. 'La Paloma' and A. laevis 'RJ Hilton' are our best sellers this year, with A. alnifolia 'Obelisk' receiving interest for its fastigiate habit.
"We recommend them to customers who ask for simple planting schemes as they are suitable for smaller gardens and are tolerant of heavy and moist soils, with little to no maintenance requirements. We stock a large range of the grafted cultivars and we sell them in a range of sizes from four- to 15-litre pots."
Neil Coldrick, proprietor, Creative Scapes, Berkshire "We use amelanchiers mainly as specimen plants for their good form and excellent autumn colours. They are good, versatile trees and shrubs that are suitable for low-maintenance gardens, as there are few problems affecting them once they are established.
"We use A. lamarckii AGM and A. canadensis for general planting but choose a more interesting type when planting them in a prominent area. As they have an open-branch system they are good for underplanting with plants such as Heuchera, Skimmia and Photinia."
SPECIES AND CULTIVARS
- A. alnifolia is a suckering shrub with creamy flowers in spring and oval to oblong, small leaves that turn red or yellow in the autumn. This species is lime-tolerant and can survive temperatures as low as -60 degsC. It can reach 4m in height and spread.
- A. alnifolia 'Obelisk' has a fastigiate habit with a dense framework of branches. Single, white flowers are produced in profusion in April. It reaches a height of around 3m.
- A. bartramiana is an erect shrub that reaches a height of 2m. White flowers are produced as singles and in small clusters, appearing in May and June.
- A. canadensis is a suckering shrub that can forms a dense plant of up to 6m and is often used by local authorities for large plantings.
- A. canadensis Rainbow Pillar has an upright and dense branching habit, which is ideal for an interesting and colourful hedge or screen. The variety can reach a height of up to 5m.
- A. x grandiflora 'Ballerina' Award of Garden Merit (AGM) reaches a height of 8m and deserves the AGM for its coppery spring foliage, large, white flowers and brilliant reddish-purple leaves in the autumn. It is ideal as a specimen tree.
- A. x grandiflora 'Robin Hill' has pink flowers that fade to white through the season. It has an upright but compact habit.
- A. 'La Paloma' is popular as a shrub because of its slow growth rate, tolerance of pruning and open habit. It has exceptional colour and flowers.
- A. laevis is a spreading, shrubby tree with bronze leaves that turn green through to orange and red, and pendent racemes of white flowers in spring.
- A. laevis 'RJ Hilton' has an upright habit with good leaf colour throughout the year and pink flowers that fade to white.
- A. laevis 'Snowflakes' forms a small, rounded, and occasionally spreading, tree with exceptionally large, white flowers.
- A. lamarckii AGM is one of the larger species, reaching a height of 10m. It produces larger leaves, which increase the impact of its excellent autumn colour and forms a spreading, graceful tree.
- A. ovalis is a medium-sized shrub with finely toothed, small leaves that are downy when young. Abundant racemes of large, white flowers are followed by berries.
- A. ovalis 'Edelweiss' forms a compact, bushy tree that has pinkish young growth and numerous large, white flowers. It is a good specimen for small gardens and patios.
- A. spicata, which is also known as A. stolonifera, is a densely upright suckering shrub that is good for creating a thicket-like hedge as it seldom grows more than 2m in height. It has short, erect racemes of white flowers, followed by blue-black fruit, and is a good choice for wildlife gardens.