Brunnera Jack Frost has to be one on the useful perennials in the garden.

It grows well in sun or partial shade and because its silver it lifts the border providing valuble high lights.
I find it a useful edging plant and have used it to edge beds planted with ferns hostas, camasia, wild primula and cowslips, bluebells and cranesbill blue geraniums and amongst other foliage plants like heuchera and heucherella.
Its finishes borders beautifully and helps the colours merge together.
When the spring leaves get a bit tatty and tired chop them back and fresh leaves will come through.