Achillea millefolium, commonly known as Yarrow, is a perennial herb valued for its feathery foliage, flat-topped flower clusters, and drought tolerance. Its self-propagating nature means that transplanting is often necessary to control its spread and maintain vigor. Moving an established clump requires a deliberate technique to minimize stress and ensure its quick return to blooming health.
Selecting the Right Time to Transplant
The most advantageous time to move Yarrow is during periods of cooler temperatures when the plant is not actively putting energy into flowering. Early spring is the preferred window, ideally before the new, low-lying growth begins to fully expand. Cooler soil and air temperatures reduce moisture loss through transpiration, which significantly lowers the risk of transplant shock before summer heat arrives.
Transplanting in the early fall, after the plant has finished flowering, is the alternative best time. Moving the plant at least six weeks before the first hard frost allows the severed roots sufficient time to establish in the new location. Transplanting during the high heat of mid-summer is strongly discouraged because the intense sun and warmth dramatically increase the plant’s moisture needs, often leading to irreversible wilting.
Preparing the New Location and Digging
Successful transplanting begins with preparing the new site to meet Yarrow’s preference for lean, well-draining conditions and full sun exposure. The relocation spot should receive a minimum of six to eight hours of direct sunlight daily, as insufficient light will cause the stems to become weak and floppy. Yarrow thrives in poor to average soil with a slightly acidic to neutral pH (6.0 to 8.0) and will suffer in rich, fertile soil, which encourages excessive foliage growth over flowers.
Before disturbing the existing plant, the new planting hole should be pre-dug to be twice as wide as the root ball and about the same depth. This wider dimension allows newly cut roots to easily expand. Use a sharp spade to cut a circle at least six to eight inches out from the center of the plant’s crown when lifting the Yarrow. Digging wide and deep ensures a substantial root ball is lifted, minimizing root damage and helping the plant retain moisture during the move.
Dividing Clumps for Better Growth
Yarrow spreads aggressively through rhizomes, and a mature clump often begins to die out in the center after several years, signaling that division is necessary. Transplanting the entire clump without division can perpetuate the overcrowding problem and lead to an unappealing, less vigorous plant in the new location. Division rejuvenates the plant by selecting and replanting only the healthiest, youngest sections from the outer edges.
Once the entire root ball is lifted from the ground, use a sharp, clean knife or the edge of a spade to cut it into smaller sections. Each new division must contain a healthy portion of roots and at least one or two visible growing points, or “eyes,” to ensure successful re-establishment. Discard the woody, non-productive center section of the original clump and replant the smaller, more vigorous divisions immediately.
Caring for the Newly Planted Yarrow
Settle the divided plants into their new environment to reduce transplant stress. Place the Yarrow division into the prepared hole so that the crown—the point where the stems meet the roots—is level with the surrounding soil line. Gently backfill the hole with soil and firm it down lightly to eliminate any air pockets that could dry out the roots.
An immediate, deep watering is required to saturate the soil and settle the roots. To reduce the demand on the newly cut root system, prune back the existing foliage by up to one-third of its height. This technique reduces the moisture the leaves lose through transpiration, allowing the plant to focus its energy on growing new roots. Monitor the plant closely for the first few weeks, providing consistent moisture until new growth indicates successful establishment.