Culture
Grow in average, medium moisture, well-drained soil in full sun to part shade. Prefers a rich, humusy soil and light, dappled sun. Intolerant of the hot and humid summers of the deep South.
Noteworthy Characteristics
Thalictrum rochebruneanum, commonly called meadow rue or lavender mist meadow rue, is a slender, clump-forming perennial which features lacy, fine-textured, bluish-green, pinnately compound, columbine-like foliage (3-4 ternate). Tiny, pendulous, lavender-purple flowers with contrasting yellow stamens appear in late summer (July-September in St. Louis) in loose, airy clusters atop sturdy, purple flower stems which rise well above the foliage to 4-6' tall (infrequently to 8'). When massed, the overall effect of the bloom can be spectacular.
Genus name comes from the Greek word thaliktron which was a name used by Dioscorides to describe a plant in this genus.
Problems
No serious insect or disease problems. Powdery mildew and rust are only occasional problems. Unlike many of the meadow rues, this species has sturdy flower stems which usually do not require staking or support.
Uses
A tall, airy plant which provides excellent foliage and late summer bloom to the perennial border, wildflower garden, meadow or naturalized area. Good background plant. Perhaps best when grouped.