Monarda are herbaceous perennials that die back to ground level each winter. Leave them standing over the winter months and cut back the dead stems to just above ground level in mid-spring. Monarda, when happy in their growing space, form wide clumps that need to be divided every 3 to 4 years to keep the plants vigorous and prevent the centers of the clumps from dying out. Dividing of the plants should happen in early to mid-spring before the plants begin to wake up. Be sure to enrich the planting hole with additional compost and Yum Yum Mix to feed the soil and provide ample nutrients for the Monarda plants to utilize.