These compact shrubs can replace perennials:

Hydrangea

'Little Quick Fire,' 'Bobo,' 'Little Lime' (pictured)

Weigela

'Spilled Wine,' 'My Monet' (pictured)

Dogwood

'Arctic Sun'

Viburnum

'Lil' Ditty,' 'Bailey Compact' (pictured)

Lilac

'Tiny Dancer,' 'Bloomerang' (pictured) Clethra

'Vanilla Spice,' 'Ruby Spice' (pictured)

Other suggestions: Spirea: 'Glow Girl,' 'Double Play/Blue Kazoo'; Ninebark: 'Tiny Wine,' 'Lemon Candy'