Geranium, Cranesbill, Hardy Geranium, Knotted Cranesbill, Pyrenees Geranium 'Silverwood'

The first G. nodosum cultivar with white flowers.

The foliage is light green but not yellow/chartreuse.

Mos...Read Moretly comes true from seed---you can rogue pink-flowered seedlings by looking for pink tints at the base of the plants.

I'd space these at least 18" apart.

About the species:

There are many other geraniums that are showier and more floriferous, but few have such a long season of bloom. In a congenial climate, this can bloom intermittently from May to frost. Petals are usually lilac to lavender-pink, with conspicuous darker veins.

The leaves have only 3 or sometimes 5 shallow lobes, which, with their glossy upper surface, gives the foliage a distinctively different texture from other hardy geraniums.

Also unusual in its tolerance for shade, and even dryish shade, though it performs best with even moisture and good drainage. Makes a good ground cover in woodland and under trees and shrubs. In congenial climates, as in England and the coastal Pacific northwest, it can tolerate sun, as long as it has reliable moisture.

Armitage says that in eastern N. America, this is hardy in Z5-7. At the Chicago Botanic Garden's 2004 hardy geranium evaluation (Z5b), two taxa managed to survive at least 4 winters and made a fair showing.

A woodland native of the the mountains of southern Europe, the Pyranees, Jura, and Alps. Perhaps a better bet for the west coast of North America than for the east.

May be divided in spring. May also be propagated by basal cuttings in early to mid-spring; root with bottom heat.

An English cultivar, its history is mentioned in this article:
...Read More target="_dgnew"rel="nofollow">http://plantheritage.wordpress.com/2012/06/11/silverwood/