Genus: Tanacetum balsamita or Chrysanthemum balsamita var. tanacetoides
Pronunciation: (Tah-nuh-SEE-tum ball-suh-MEE-tuh)
Family: Compositae (Asteraceae)
• Hardy perennial reaching 3 to 4 feet in height
Costmary is an herb of many names. Its principal common name shows it to be an herb dedicated to the Virgin Mary. The alternate name, sweet Mary, likely refers to the Virgin Mary, too, or it could refer to Mary Magdalene: the early herbalists Gerard and Culpeper mentioned an herb called maudlin (Magdalene) which was identical or very similar to costmary.
Other common names for costmary allude to its uses. As a flavoring of ales and spiced wine, it was called alecost. The name allspice applied to this herb may be a variant spelling for ale-spice, or perhaps the herb’s scent reminded someone of the spice allspice. Sweet tongue, a common name in Maine, refers to both the taste and the shape of the leaves.
The large, oblong leaves of costmary make neat, fragrant bookmarks, a use that spawned the old names Bible leaf or Bible plant. The minty odor, which persists in the dried leaf, might repel silverfish or book lice from the family Bible, and the leaf could be sniffed surreptitiously during long sermons to maintain wakefulness.
Mint geranium is a misnomer: costmary is closely related neither to the mints (Lamiaceae/Labiatae) nor to the geraniums (Geraniaceae); there’s nothing geraniumlike about its appearance or odor, and it is minty only in smell and taste. Another name referring to its odor is balsam herb. To add to the confusion, the name costmary has also been applied to tansy (Tanacetum vulgare), to which our Herb to Know is closely related.
The scientific names of costmary seem as slippery as the common ones. Long known as T. balsamita and before that as Balsamita major or B. mas, costmary more recently has appeared widely as Chrysanthemum balsamita or as C. b. var. tanacetoides. The highly respected four-volume New Royal Horticultural Society Dictionary of Gardening (1992) lists costmary as T. balsamita as does The Big Book of Herbs (Interweave, 2000) by Arthur O. Tucker, Ph.D. and Thomas Debaggio. But you may still find it listed by some nurseries as C. balsamita.
Description of Costmary
Stiff, leafy stalks of costmary rise from spreading rhizomes. The upward-pointing, silvery-haired, pale-green leaves with fine, rounded teeth may measure as large as 12 by 2 inches. Lower leaves are stalked and large, the upper ones stalkless and progressively smaller. The flowers, in clusters of tiny yellow buttons at the top of 3-foot stalks, bloom in very late summer in northern climates, not at all if plants are grown in shade. Plants whose flowers have minute white ray flowers used to be classified as C. balsamita, whereas those with no ray flowers (just yellow disk flowers like those of tansy) were assigned to var. tanacetoides (which means “like tansy”). Gertrude B. Foster, in Herbs for Every Garden (1966), noted that the former has a camphor scent and the latter a mint scent. Madalene Hill and Gwen Barclay, in Southern Herb Growing (1987), found the scent of C. balsamita reminiscent of wintergreen, and that of a cultivar, C. b. ‘Camphor’, to be “the clean, crisp aroma of camphor.” When shopping for a costmary plant, therefore, sniff and compare. And don’t just press fresh costmary leaves in the family Bible; first dry potential bookmarks between layers of clean newsprint and under a heavy weight. This will ensure that the pages don’t warp or become discolored.
Like most other herbs, costmary was once used medicinally to treat a variety of ills, including dysentery, “quotidien ague,” “evil, weak, and cold livers,” and “stoppings” of the brain. It has also been used to bring on delayed menstrual periods; if you are pregnant, avoid internal use. The herb is astringent and was commonly taken internally as a tea or mixed with sugar as a conserve. Externally, it could be mixed with other herbs into ointments used to treat sores and itching. Today, we’re more likely to use the leaves to scent a relaxing bath or to dry them for use in sachets and potpourri.
The mint-flavored form of costmary can be used in cooking, though Frances A. Bardswell’s description (in The Herb Garden, 1930) of the flavor as “like weak Mint sauce” with “an after-taste of bitterness” isn’t much of an endoresement. Try using the fresh, young leaves in iced tea and in green or fruit salads and coleslaw. Add some shredded leaves to soups and cream sauces, too. Cover fish with a whole large leaf before baking it, or place one in the bottom of a cake tin before pouring in the batter.
Costmary can be used around the home as well. The Big Book of Herbs suggests using it with rosemary, cloves, bay, cinnamon, and sage for potpourri.
More common in gardens a few centuries ago, costmary makes a fine ornamental today, especially in combination with other large-leaved herbs such as comfrey, elecampane, and borage. Scented geraniums, sages, and colorful nasturtiums are other good companions. Place costmary behind lower-growing herbs such as thymes but definitely in front of giants such as elecampane.
This hardy, tolerant herb from southern Europe and western Asia withstands cold winters as well as humid southern summers. Dry soil suits it fine: clay, sand, and loam. Costmary will take either sun or partial shade, but it needs full sun to produce flowers. To keep plants growing vigorously and neatly, divide them every three years in spring or fall. Set divisions about 2 feet apart; the rhizomes will fill in empty spots. Don’t bother trying to grow this plant from seed.
• Carroll Gardens, 444 East Main St., Westminster, MD 21157; (800) 638-6334; www.carrollgardens.com.
• Goodwin Creek Gardens, P.O. Box 83, Williams, OR 97544; (800) 846-7359; www.goodwincreekgardens.com.