Lysimachia clethroides (Gooseneck loosestrife)
Easily grown in average, medium, well-drained soil in full sun to part shade. Prefers moist, rich, humusy locations in full sun, but spreads by rhizomes and can be very aggressive in these ideal growing conditions. Tends to be somewhat less aggressive if grown in drier soils with light shade.
Best when massed in a wild garden or remote part of the border where it can be allowed to naturalize in broad drifts without posing a threat to less vigorous perennials. May be grown effectively against man-made barriers, such as garages or sheds, where growth would be limited with a minimum of effort. Also may be grown effectively in moist soils along or near streams or ponds or in wet meadows.