Description of Achillea ptarmica 'The Pearl'

Achillea ptarmica 'The Pearl' is a reliable, long-flowering yarrow with small, double white flowerheads. Many gardeners know it as sneezewort 'The Pearl'. It is useful when you want white flowers near water without a plant that flops into the pond.

Appearance

Achillea ptarmica 'The Pearl' forms a spreading clump of narrow, toothed leaves. The foliage stays a clean green and looks tidy from spring onwards. Flower stems rise above the leaves and carry lots of button-like blooms. Each flowerhead is packed with petals, so it reads as a soft white dot from a distance. Expect flowering from early summer into late summer, and often later if you keep cutting spent stems. In good conditions it reaches about 60 to 90cm tall, with a spread around 45 to 60cm as it slowly creeps out.

This plant fits well with rushes and sedges because it adds a different leaf shape. It also sits nicely beside candelabra primroses, marsh marigolds, and ferns where the ground stays cool.

Care Guide

Plant Achillea ptarmica 'The Pearl' in sun or light shade. Full sun gives the best flowering, but it still performs well with a few hours of shade, which is common near ponds and bog gardens. Give it fertile soil that stays moist. It can handle average garden soil once established, yet it looks better and flowers for longer when the roots do not dry out.

• Water: Keep it evenly moist in its first season. After that, water in dry spells, especially if it is in a raised bog planter.
• Feeding: A spring mulch of garden compost is enough. If growth looks weak, a light feed in late spring helps.
• Cutting back: After a flush of flowers, cut stems down by about a third. You often get a second run. In autumn, cut the whole plant to ground level.
• Division: Split clumps every 2 to 3 years in spring. This keeps flowering strong and stops it spreading into neighbours.

Suitability for Bog Garden

Achillea ptarmica 'The Pearl' suits the drier parts of a bog garden and the damp edge of a pond where water drains slowly. It does not want its crown under water, so avoid planting in standing water or the deepest sump zone. Use it on a gentle slope or the top tier of a bog where the soil stays wet but airy. It works well in mixed planting because it does not need special peat mixes or rainwater only care. If you want a white-flowered plant that still looks good after heavy rain, this one earns its space.