I saw this growing in someone's garden and it was such a beautiful shrub. Unfortunately I can't ask the person about it, but I googled and found the following (I don't know how you will be able to prune it after it flowers though, if it never flowers)
from
http://www.gardenseeker.com/pruning/pruning_exochorda.htmPruning Exochorda - The Bride. How and when to prune this shrub.
Also known as The bride, or The Pearl Bush Exochorda x macrantha The Bride.
The pure white flowers of this shrub give rise to the name - The Bride - or the Pearl Bush. (The opening flower buds resemble groups of pearls>
Exochorda x macrantha The Bride, is an early summer flowering shrub that needs pruning at the correct time. How and when to prune it is detailed below.
Take note of our information and advice on how to prune the Exochorda and avoid the disappointment sometimes experienced with this plant.
Exochorda x macrantha The Bride, is a spring or early summer flowering shrub, with arching branches of purest white flowers.
The secret of this shrub, is that you carry out the pruning at the right time. If you prune it too leate - or too early, then you will lose much of the flowering growths.
It flowers on stems which are made in the mid to late summer. It will not flower on new stems if you prune it early in the spring.
For success, you will need to prune The Bride immediately after it has finished flowering, and certainly before the summer sets in. This prompt pruning action will enable the shrub to grow long arching stems throughout the summer growing season which will then provide huge trusses of white flowers the following spring.
Prune the finished flowering stems back to half their length to build up a fantastic network of arching stems. Do this pruning right after flowering like outlined, and don't be afraid of pruning right back into the shrub. Every branch that has borne flowers should be pruned this way.
Together with this, prune out around one third of the older stems/branches - right down to within a few cm (ins) form the ground. new shoots will sprout forth after this basal pruning, and form a framework of healthy new branches for flowering in later years. Prune further old stems out in each year.
After a few years of this basal pruning - in conjunction with the pruning as outlined above, and you will end up with a vigorous shrub - full of new growth, just waiting to smother itself with masses of white flowers. Don't forget when to prune. Do it right after flowering.