Gypsophila repens 'Filou White'

Gypsophila repens 'Filou White' A beautiful work-horse of a plant that should be in every garden whether in a rock garden, trough, or the front of a mixed boarder. They grey-green foliage forms a low mat only a few inches tall, and a foot or more in diameter, spreading flat or trailing beautifully over rocks and container edges if given a chance. Starting in early spring it covers itself with profuse white baby's breath flowers, and it simply doesn't quit blooming until well after the last frost. Why grow annuals like alyssum when this thing will give just as good and long lasting a show AND is a tough, hardy, perennial? Zone 5, at least