Achillea ptarmica Boule de Neige

The Achillea ptarmica 'Boule de Neige' is a wonderful variety of sneezeweed with double flowers, vigorous and highly floriferous throughout the summer. Sprinkled with fluffy white pom-pom flowers, this rounded tuft-shaped perennial appears covered in snowflakes. Unlike many other yarrows, this one prefers moist to even wet, non-limestone soils. Very hardy and charming, it thrives in full sun or partial shade, in flower beds, and near water sources. 

The Achillea ptarmica 'Boule de Neige' is a deciduous perennial herbaceous plant belonging to the Aster family with a creeping rhizomatous rootstock. Its above-ground growth emerges in spring, dries up and disappears in autumn. Its ancestor, sometimes called silver buttons, sneezewort, marsh yarrow, sneezeweed or stone-breaker, is a species widespread in northern Europe and Asia. Its natural habitat consists of meadows and wet areas. This 'Snowball' variety has a bushy and carpeting habit. The slightly creeping stems bear slender, lanceolate, dark green leaves. Flowering occurs from July to September. At the end of 60 cm (24in) tall stems, numerous pure white, double flowers with a diameter of 1 cm (1in) appear.

The Achillea ptarmica 'Boule de Neige', which is highly frost-tolerant (-20°C), makes a lovely companion for other perennials that prefer moist to wet soils. For example, you can pair it with ragged robin, astilbes, plume thistle, and meadowsweet (Filipendula). Aphids often attack sneezewort to the point that it is known in organic gardening to prevent or avoid other plants from being invaded by aphids. It is ideal in herb gardens, flower beds, wildflower meadows, or as a cut flower. It pairs well with Caucasian scabious and phlox.