Firefly Diamond Yarrow

‘Firefly Diamond’ yarrow is an upright perennial with dark-green, finely divided foliage and broad clusters of ivory-white flowers. The long-lasting blooms hold their color as they age, making this compact cultivar useful in sunny borders, repeated plantings, and cut-flower beds. ## Form and flowering Proven Winners lists mature height at 24–28 inches and spread at 32–40 inches, with USDA Zones 3–8. Proven Winners describes the habit as upright and columnar; the patent records a mounded three-year-old trial plant in Michigan reaching 70 cm tall by 100 cm wide. In a three-year-old Michigan trial plant, the patent reports flowering for about seven weeks from late June and repeat bloom after deadheading. Its plant patent USPP 32,986 was granted on April 20, 2021. ## Growing conditions Plant in full sun and well-drained average or poor soil; avoid overly rich beds. Proven Winners lists average water needs and also labels this cultivar drought tolerant. Its [yarrow care guide](https://serv3.provenwinners.com/learn/how-plant/yarrow) recommends regular watering until roots establish, after which established yarrow can withstand dry periods. Border, mass-planting, cut-flower, and dried-flower uses are listed by the [brand profile](https://www.provenwinners.com/plants/achillea/firefly-diamond-yarrow-achillea-hybrid); the [plant patent](https://patents.justia.com/patent/PP32986) also notes its value as a specimen or in groups. ## Maintenance Water while the plant establishes, then let well-drained soil dry between waterings. Remove faded flower clusters to encourage another flush, and cut the plant back by half after flowering as Proven Winners directs. Give it room for its mature spread.