Achillea Marshmallow

Achillea ptarmica 'Marshmallow' Sneezewort 'Marshmallow'

Soft, fluffy, double white pompom flowers held on slender stems above a clump of fresh green foliage — 'Marshmallow' is the achillea that earns its name from the moment the buds open, giving you clouds of pillowy white from midsummer to autumn.

A close relative of 'Ballerina' but with a more relaxed, vigorous habit, 'Marshmallow' is the floriferous workhorse of the Achillea ptarmica family. The double white flowers — small, soft, button-like — bloom in such generous numbers that established clumps can produce hundreds of stems in a single season. Like all ptarmica, this is a plant of damp meadows in the wild, which means it will happily grow in heavier, moisture-retentive soils that defeat the more familiar millefolium yarrows. RHS Plants for Pollinators recognised, and one of the finest white cut flowers for the cottage cutting patch.

A note on growing

Surface-sow indoors from February to April — don't cover the tiny seeds, as achillea needs light to germinate. Keep at 18–20°C; germination takes 10–14 days. Plant out after the last frost. Unlike most yarrows, 'Marshmallow' actively prefers slightly damp ground and will thrive where standard yarrow would sulk. Full sun is ideal but partial shade is tolerated. The plant spreads via underground rhizomes — vigorous in rich soil, more restrained in poor — so divide every three years in spring to keep it energetic and prevent it overrunning neighbours.

Where it shines

A florist's favourite for its long vase life and the sheer quantity of stems a mature clump produces. Outstanding as a filler in mixed bouquets — the soft white cloud softens any combination — and it dries beautifully for everlasting arrangements and wreaths. In the cottage border, it's the traditional partner to shrub roses, hiding their leggy stems with a froth of white. The open flower form is genuinely useful for short-tongued pollinators that struggle with more elaborate doubles.

Plant alongside

For the classic cottage garden look, plant alongside shrub roses and let 'Marshmallow' hide their bare stems in a cloud of white. For colour contrast, combine with the deep blue spikes of Larkspur or the cerise plates of Achillea 'Cerise Queen'. For an all-white border, pair with Achillea 'Ballerina' and Ammi majus.