Mullein (Verbascum spp.) is a striking plant prized by gardeners for its tall flower spikes and distinctive velvety foliage. This plant is classified as a biennial, meaning its entire life cycle spans two seasons, which directly impacts its transplant success. Moving mullein is notoriously challenging because it develops a central taproot in its first year of growth. This taproot anchors the plant deeply and is highly sensitive to disturbance, making careful, timely execution necessary for survival.
Determining the Best Time for Transplanting Mullein
The timing of the move is the most important factor in maximizing the survival rate for mullein. The best time to move a mullein is when it is a first-year rosette, which is the low-growing, leafy stage before the flower stalk appears. This young stage has not yet developed its full, deep taproot, making it more adaptable to being moved.
If you must move a larger plant, aim for the period of dormancy, which is typically late fall or very early spring before active growth begins. Transplanting a mature mullein in its second year—especially one that is already flowering—is almost always unsuccessful. The taproot is fully formed, and the plant is investing all its energy into producing the final flower and seeds.
Site and Plant Preparation Before Moving
Thorough preparation of both the new site and the plant itself will greatly reduce the stress of the move. Mullein thrives in full sun, requiring at least six hours of direct light daily, and prefers poor to average, well-draining soil with a pH between 6.0 and 7.0. Before you begin to dig up the plant, the new location must be ready to accept the roots immediately.
Dig the receiving hole first, making it approximately twice as wide as the mullein’s current root ball, but only as deep. The crown of the plant—where the stems meet the roots—must sit level with the surrounding soil surface, not lower. To ensure the root ball remains cohesive during excavation, deeply water the mullein in its original location 12 to 24 hours before the planned move. This pre-watering saturates the soil, helping it cling to the delicate roots when lifted.
Step-by-Step Guide to the Physical Move
The actual physical move requires careful technique to preserve as much of the taproot as possible. Begin by using a sharp spade or garden fork to mark a generous circle around the mullein, approximately 8 to 12 inches away from the rosette. This wide perimeter is necessary to capture the lateral roots and a significant portion of the central taproot.
Slowly and methodically drive the spade straight down along this marked circle to sever the outer roots, then work the tool gently underneath the root ball. Once you feel the root mass loosen, carefully lift the entire root ball, trying to keep the soil intact around the roots. Immediately transfer the mullein to the prepared hole in the new location, positioning it so the top of the root ball is flush with the surrounding grade.
Begin backfilling the hole with the excavated native soil, gently firming it around the root ball as you go. Avoid excessive compaction, but ensure there are no large air pockets. Once the hole is filled, create a small, shallow soil berm around the edge of the planting area to help contain water for the initial deep watering. The entire process should be completed as quickly as possible to minimize the time the roots are exposed to the air.
Post-Transplant Care and Establishment
Immediate and consistent hydration is the first action necessary following the transplant. Water the mullein deeply and slowly right after planting to settle the soil around the roots and eliminate any remaining air pockets. This deep watering ensures moisture reaches the entire depth of the root ball and the surrounding soil.
For the next two to three weeks, maintain consistent soil moisture, keeping the area damp but never saturated or waterlogged. The mullein needs moisture to establish new feeder roots, but overwatering can lead to root rot in the disturbed soil. Monitor the plant daily for signs of wilting, which is the most common symptom of transplant shock.
If the move occurred during warm or intensely sunny weather, providing temporary shade for the first week can help mitigate shock by reducing moisture loss through the leaves. A shade cloth or a nearby chair positioned to block the harshest afternoon sun can provide this temporary relief. Do not apply fertilizer immediately, as the plant needs to focus its energy on root growth, not foliage production.