Chrysanthemums (mums) are popular garden perennials that sometimes require relocation to maintain health and vigor. Transplanting is necessary when clumps become overcrowded and need division (typically every three to five years), or when moving them to a more suitable location. This process allows the plant to access fresh nutrients and prevents the exhaustion of the surrounding soil. While mums are resilient, a careful and timely procedure is required to minimize stress on the root system and ensure a successful move.
Determining the Optimal Time for Transplanting
The most favorable window for transplanting chrysanthemums is in the early spring, just as new growth begins to emerge. Moving the plant at this time allows the root system to establish itself fully before the onset of summer heat and the plant’s main flowering period. A newly established root system needs many weeks to anchor itself and gather resources, making spring the least stressful time for relocation.
It is not recommended to transplant mums during the late summer or fall, especially in colder climates, because the roots will not have sufficient time to acclimate before the ground freezes. The plant needs at least six weeks of moderate temperatures to develop a robust root structure capable of surviving the winter. If a fall move is unavoidable, attempt it well before the first expected hard frost. Avoid transplanting during periods of extreme heat, drought, or heavy rain, as these conditions increase the likelihood of transplant shock.
Pre-Transplant Site and Plant Preparation
Selecting the new planting site requires attention to the specific environmental needs of the chrysanthemum. Mums perform best in full sun, meaning at least six hours of direct sunlight daily. Adequate sun exposure is necessary for the plant to produce a robust structure and abundant blooms. The chosen location must also offer well-drained soil, as chrysanthemums quickly develop root rot if they sit in standing water.
Preparing the planting area involves loosening the soil and incorporating organic matter. The soil should be amended with materials such as compost, aged manure, or peat moss to enhance fertility and improve drainage. Work this organic material into the native soil to a depth of approximately six inches to create an optimal growing medium.
A day or two before the move, thoroughly water the existing plant to ensure its root ball is fully saturated. This pre-soaking helps the soil adhere to the roots, minimizing damage during extraction. If transplanting a mature clump, pruning back any old, dead growth to within a few inches of the ground in early spring redirects the plant’s energy toward root growth. This preparation helps reduce the overall stress the plant will experience.
Executing the Physical Move
Begin the physical process by digging the new planting hole, which should be approximately twice as wide as the mum’s current root ball. The depth of the hole must be exactly the same as the original planting depth, as planting too deep can lead to stem rot. Use a sharp spade or shovel to dig wide around the perimeter of the clump, ensuring the largest possible root mass is retained. Carefully lift the entire root ball from the ground, taking care not to let it crumble apart.
If the plant is overgrown, this is the ideal time to divide it for rejuvenation. Healthier, new growth is typically found on the outer edges of the clump, while the center may be woody and unproductive. Use a sharp knife or the edge of the spade to separate the outer sections, ensuring each new division has several healthy shoots and a substantial portion of the root system. Discard the old, woody center section.
Place the newly divided section or the intact plant into the prepared hole, ensuring the top of the root ball is level with the surrounding soil. Backfill gently with the amended soil, firming it moderately to remove any large air pockets without overly compacting the soil.
Post-Transplant Establishment Care
Immediately after placing the chrysanthemum in its new location, water it thoroughly to settle the soil around the roots and eliminate any remaining air gaps. For the next few weeks, maintaining a consistent watering schedule is paramount for root establishment. The soil should be kept evenly moist but never saturated, which would deprive the roots of oxygen.
Applying a layer of mulch, such as shredded bark or compost, helps retain soil moisture and regulate the temperature around the new roots. A layer two to three inches deep is sufficient, but keep the mulch pulled back a few inches from the plant’s main crown to prevent moisture buildup and subsequent rot. Monitor newly transplanted mums closely for signs of transplant shock, such as sudden wilting or leaf drop.
If the plant shows signs of distress, temporary shading from intense afternoon sun may be beneficial. While the plant is focusing on root development, avoid heavy fertilization. A water-soluble root stimulator or a balanced, low-concentration fertilizer can be applied right after planting to encourage the rapid growth of new feeder roots.