I've said a lot about lilac recently but I was in the large deciduous shrub beds yesterday and this one has a white trim to the blossom. It is just stunning. It is called Syringa vulgaris Sensation. Quiet an appropriate name.
Vulgaris varieties can grow to about 4 m comfortably. Easy to grow into a small tree. Prune after flowering to maintain a more compact shape. There are dwarf varieties and standards also available.
