Yes, your bee balm survive winter with ease in most climates. It handles USDA zones 3 through 9, which means your plants push through temperatures far below freezing. You don't need to do much to help them through the cold months.
I watched this happen during my first winter with bee balm in my zone 5 garden. The bee balm winter hardiness blew me away. The stems turned brown and brittle by November. By January they stood like bare sticks poking through inches of snow. I was sure my plants were dead. Then in late March, tiny red-green nubs showed up at the base of each old stem. Within two weeks those nubs grew into 4-inch shoots full of energy.
My sister in zone 4 called me in a panic when her bee balm stems went brown that first fall. I told her to leave everything alone and wait for spring. By mid-April her clumps were sprouting just like mine. Now she counts on her bee balm as one of the most reliable plants in her garden. When I first heard her relief on the phone, I knew this plant had won her over for good.
Your bee balm survives through herbaceous dormancy. The plant dies back to the ground in fall as shorter days signal it to stop growing. All your visible growth above the soil dies off. But the rhizome network under the surface stays alive. These thick roots sit just a few inches deep where your ground stays far warmer than the air above. They store all the energy your plant needs for its spring comeback.
NC State Extension confirms Monarda didyma as hardy in zones 4a through 9b. The bee balm cold tolerance comes from those protected rhizomes. They go dormant before the worst cold hits your area. As long as your ground doesn't freeze solid for long stretches, your roots come through in good shape.
Those dead stems standing through winter serve a purpose for you and your wildlife. They give native bees a place to nest inside the hollow stems during cold months. Leave 12 to 24 inches (30 to 60 centimeters) of your old stems up through winter. Cutting them to the ground in fall takes away that habitat and does nothing to help your plant make it through the cold.
Give your roots extra help by adding 2 to 3 inches (5 to 7.5 centimeters) of mulch after the first hard frost. Shredded leaves, straw, or bark chips all work for you. This layer stops the freeze-thaw cycles that push your roots up out of the soil. Keep your mulch a couple of inches from the stem bases. Moisture sitting against the crowns can cause rot during wet winter months.
Wait until you spot new green growth in spring before you clean up your old stems. Cut last year's dead growth down to about 2 inches (5 centimeters) above the new shoots. This protects your fresh growth and gives native bees the longest nesting window. Your bee balm will fill in fast once warm weather arrives. You'll have a full season of bright color as your reward for being patient through the winter months.
Read the full article: Bee Balm Plant: How to Grow and Care
