This will depend on which type of amelanchier you are growing and whether you really want to keep it. Some turn into large globular shrubs and some develop into small trees. In either case they rarely exceed five metres in height - so yours will probably not get much larger.
If you are growing a tree-like amelanchier, you could restrict it by pruning the canopy using a pruning saw. This should be done when the tree is dormant, between November and late February, when you can also see the shape of the branches. However winter pruning will always be at the expense of next spring’s flower.
If it’s a shrubby suckering form I would suggest stooling (ie cutting down to the ground) straight after flowering. But I would err on the side of caution and just do half in the first year. Or you could 'lift the skirt' of the shrubbier sorts by removing the lower branches to a height of two feet. This will allow you to plant right up to the main stem, but only with shade lovers. Whichever method you use, your amelanchier will grow back to its former size (or larger) relatively quickly. If this isn’t acceptable, remove it.
Leaving your amelanchier in
This need not be a disaster because the white blossom and dark foliage make a perfect foil for dark, sultry tulips or a mixture of pink and purple tulips. These could be bought now for planting in November or December. Choose late-April or May-flowering varieties to coincide with the amelanchier flowers. You could also plant pulmonarias with pink-toned flowers. 'Leopard' is a brick-pink with green foliage marked with regular silver splashes and 'Raspberry Splash' is a small flowered raspberry pink with narrow leaves. Or use a blue variety like 'Trevi Fountain' (www.plantsforshade.co.uk have a good selection).
What is an amelanchier?
There are ten species, mostly from North America, and they are sometimes called snowy mespilus. This name refers to the white, starry flowers that appear in late spring - mostly on bare wood. The fresh copper-red leaves emerge just as the flowers finish and the foliage turns green in summer before reddening up again in autumn. This moisture-loving tree can also produce edible, currant-like fruits in autumn - so generally it’s a good choice for a small garden. June service berry is another name that’s sometimes used as well. These ornamental trees and shrubs enjoy growing on clay in an open position. They are not fussy, but they don’t do well on limey soil.
The best three amelanchiers
Amelanchier x grandiflora 'Robin Hill'
(6 - 8 m)
A recently introduced cultivar which has clusters of pink buds that open into pale pink flowers in spring. These flowers then fade to white before falling. Edible berries follow from June until August. The young leaves are an attractive bronze colour when they first emerge, darkening to a lush green in late spring and summer. In the autumn they turning vivid shades or orange/deep-red before falling. Forms a small garden tree.
Amelanchier lamarckii 'Ballerina'
(4 - 5 m)
A delightful, low maintenance shrub or small tree which is covered with large white flowers in spring. In spring/summer, the leaves are an attractive, cool green turning shades of bright red/orange /gold in the autumn before falling. A superb choice for planting as a either a stand-alone specimen or as part of a mixed border.
Amelanchier ovalis 'Edelweiss'
(3 - 4 m)
A slower-growing amelanchier, a native of Central and Southern Europe, has six-inch long panicles of white flowers in late spring. The leaves are a pink-bronze when young, darkening to cool green in spring and summer before turning to eye-catching shades of orange, red and yellow in a crisp autumn. Once established, this tree produces small black fruit in mid to late summer which are popular with birds. A superb ornamental plant which is suitable to gardens of most sizes.
Available from Bluebell Nursery (www.bluebellnursery.com)