Phlox, a genus of hardy perennial flowering plants known for its vibrant, clustered blooms, can be transplanted successfully. Gardeners move these plants to control size, rejuvenate older clumps, or propagate new plants. Varieties range from the tall garden phlox (Phlox paniculata) to the low-growing creeping phlox (Phlox subulata). Success depends on minimizing stress to the plant’s root system during the transfer.
Optimal Timing and Site Preparation
The most favorable periods for relocating phlox are early spring, just as new growth emerges, or late summer into early fall. Moving the plant during these cooler periods allows it to establish new roots before the stress of summer heat or winter dormancy. Fall transplanting should occur at least four to six weeks before the ground freezes to give the roots enough time to anchor. Avoid transplanting on hot, sunny days, which can induce severe water stress and transplant shock.
Preparation of the new planting site is important. Phlox thrives in well-draining soil rich in organic matter. The new hole should be dug wider than the root ball, about one-and-a-half times the width, but no deeper than its current depth. Incorporating compost or well-rotted manure into the backfill soil improves drainage and provides nutrients as the plant settles in.
Step-by-Step Transplanting Technique
The day before the planned move, thoroughly water the phlox in its original location. This hydrates the plant and makes the soil cohesive, helping the root ball stay intact during the transfer and reducing transplant shock. Use a sharp spade to cut a wide circle around the plant, ensuring the circumference is large enough to capture most of the feeder roots.
Carefully work the spade beneath the root ball to lift the entire clump out of the ground, keeping the soil around the roots as undisturbed as possible. If the plant is large, it can be divided into smaller sections using a sharp tool, ensuring each new division has three to five healthy shoots and a substantial root mass. Place the removed phlox into the prepared new hole, making sure the crown—where the stem meets the roots—sits level with the surrounding soil surface.
Spread the roots gently outward in the hole before backfilling with the amended soil mixture. Lightly firm the soil around the base to eliminate any air pockets, which can dry out the roots. Do not pack the soil too tightly, as this can impede water and oxygen exchange necessary for new root growth.
Essential Post-Move Care
Immediately after the phlox is settled, provide a deep, thorough watering to help the soil settle around the roots and fully hydrate the plant. Maintaining consistent moisture for the next few weeks is crucial for root establishment. The soil should remain moist but never waterlogged, as excessive saturation can suffocate the developing roots.
To reduce the plant’s water demand while the roots recover, prune back the foliage by about one-third, especially if the plant was in bloom. Apply an organic mulch layer around the base, keeping it a few inches away from the stems, to retain soil moisture and regulate temperature. Avoid applying heavy fertilizer immediately, as the high salt content can further stress the newly planted roots; wait until you see signs of vigorous new growth.