Costmary Plants In The Garden
Costmary, Tanacetum balsamita, is one of those herbs that used to be in every herb garden but is now rarely seen. The costmary herb plant is a hardy herb that tolerates hot summer and cold winters. It thrives in nearly any type of poor, dry soil, including clay and sand. Although the plant grows in partial shade, blooming is best in full sunlight. In the herb garden, this tall plant, which reaches heights of 2 to 3 feet, is lovely behind shorter herbs such as thyme, oregano, or sage. Nasturtiums or other colorful bloomers can be planted to complement costmary’s bright green foliage. Purchase costmary plants at a nursery or greenhouse, or ask gardening friends to share divisions from established plants. The plant spreads by underground rhizomes and is extremely difficult—if not impossible—to grow from seed.
Caring for costmary in your garden is an easy task; once established, the herb requires no fertilizer and rarely needs water. Allow at least 12 inches between each plant. Costmary benefits from division every two to three years to prevent the plant from becoming tired and overgrown. Dig the clump in spring or autumn, then pull the rhizomes apart with your hands or separate them with a knife or shovel. Replant the divisions or give them away.