Lycopus uniflorus thrives in consistently moist to wet conditions. Ensure the soil never dries out completely, especially during active growth. It can tolerate standing water and is well-suited for boggy areas, rain gardens, or pond margins. Regular watering is crucial if grown in drier garden beds.

Pruning Lycopus uniflorus is primarily focused on managing its vigorous growth and maintaining a desired aesthetic. After the flowering period, spent flower stalks should be cut back to prevent the plant from self-seeding, which can contribute to its spread. More importantly, aggressive pruning of its underground rhizomes is often necessary to control its invasive tendencies in garden settings. This involves regularly digging up and removing unwanted runners and sections of the root system to keep the plant within its designated boundaries.

Lycopus uniflorus is easily propagated by division of its rhizomes, which can be done in spring or fall. Simply dig up a clump, separate sections containing roots and shoots, and replant them in suitable moist locations. It can also be propagated by seed, though germination may be slower and less reliable.

While not typically grown in pots due to its spreading nature, if cultivated in containers to restrict growth, repotting may be necessary annually. Choose a slightly larger pot and refresh the soil with a rich, moisture-retentive mix. This also provides an opportunity to divide the plant and manage its root system.