By Deb Soule, Herbalist and Founder of Avena Botanicals
In southern Maine, the linden trees begin blooming late June. Their sweet fragrance invites thousands of honey bees to feed upon the abundant nectar that the yellowish-green blossoms produce. Linden, also known as American Basswood (Tilia americana), can be found scattered throughout Maine. The European Linden (Tilia europeae) and the Little-Leaf Linden (T. cordata) are commonly used by New England landscapers for shade trees. (Baxter Boulevard in Portland, Maine is lined with both species.) Tilia europea and T. cordata are shorter and contain smaller leaves than our native species which grows to a height of 50-70 feet and a diameter of 2-3 feet.
The genus Tilia encompasses about 30 species of trees, native throughout most of the temperate Northern Hemisphere, in Asia (where the greatest species diversity is found), Europe and eastern North America. In most herb books, Linden is listed in the Tiliacea Family. However, genetic research by the APG has more recently incorporated the Tiliacea Family into the Malvaceae Family.
American Basswood's leaves are 5-6 inches long, heart-shaped, toothed, and a dark green color on the upper surface. Young leaves tend to be hairy. Each flowers' five petals grow to be 7-12mm long and are found at the base of a slender stalk which is attached to a long, narrow, yellowish leaf-like bract. The hard, woody round fruit, containing 1-2 seeds, is covered with short, brown-colored hairs, and is approximately the size of a pea. These fruits remain attached to the leaf-like bract, aiding the wind in carrying the seeds as they drop. The bark of old trees is deeply furrowed while the bark on young trees is smooth or slightly fissured and a grey color.
In her book, Medicinal and Other Uses of North American Plants: A Historical Survey with Special Reference to the Eastern Indian Tribes, Charlotte Erichsen-Brown references how several different Native American tribes relied heavily on the inner bark for cordage, basketry, mats and many other utilitarian objects. The wood continues to be appreciated by various artists, including wood carvers and furniture makers, as it is soft and easy to work with.
I first met a row of Linden trees, lining the dirt drive of an old farm in southern Maine, while they were in full bloom. I stood mesmerized by the loud and ceaseless sound of the honey bees frantically collecting the nectar. The air was truly thick with the sweet fragrance of the linden's flowers. This hedgerow of 50 foot tall trees made a cool, shady canopy that was lovely to hang out under during the heat of June and July.
Farmers, gardeners and herbalists alike will benefit from planting the native and European species. Linden can be propagated by seed, cuttings, young saplings (available through FEDCO Trees and other tree nurseries) or by grafting. A hedgerow of lindens planted on the windward side of an orchard offers excellent protection for young trees and will attract pollinators to the orchard or farm once the trees begin producing flowers. The FEDCO tree catalog says that linden prefers deep rich moist soils, but will grow in dry heavier alkaline soils, in full sun or partial shade. The catalog also says the Tilia americana species is sensitive to salt and pollution, grows from New Brunswick south to Virginia, and may live up to 900 years.
Linden flowers are gathered by climbing a ladder or better yet, by keeping some of your trees pruned so flower collecting can happen with more ease. The flowers and leaf bract dry quickly and store well in air-tight, glass jars. You can also make a tincture from either fresh or dry flowers and leaves. Best to collect the flowers when they first open and in the early morning hours when the air is still fresh and cool and the flowers fragrant. The famous European herbalist Juliette de Bairacli Levy always taught that the medicine of flowers is stronger when the flowers are collected before too many bees have visited them.
The first cup of linden flower tea I ever enjoyed was while visiting friends in England, where it is called lime blossom. In Europe the flowers are commonly used as a beverage tea alone or in combination with chamomile and honey. A warm cup of linden and chamomile flowers helps to reduce irritation and restlessness and promotes a restful sleep. The flowers' aroma and flavor is delicate and sweet, creating a relaxing and pleasant tasting tea. A hot tea, made with linden, elder flowers and chamomile, acts as a diaphoretic and is effective for lowering a fever and helping resolve a cold or flu. Even linden flowers alone, along with bed rest, can be extremely helpful for children and seniors with fevers and influenza symptoms. Consider using the tea for easing a swollen, red sore throat, laryngitis, and a dry cough where thirst and irritability are also present.
Linden is highly regarded as a relaxing remedy, easing nervous tension and stress. British Herbalist David Hoffman writes about the Tilia europea species: “It has a reputation as a prophylactic against the development of arteriosclerosis and hypertension. It is considered to be a specific in the treatment of raised blood pressure associated with arteriosclerosis and nervous tension. Its relaxing action combined with a general effect upon the circulatory system give Linden a role in the treatment of some forms of migraine.”
European herbalists in general value the Linden flower for its restorative effect on blood-vessel walls. “There is a persistent reputation for it helping with cases of arteriosclerosis (like the horse chestnut, that shares a similar saponin). Modern practice has also seen its potential in the treatment of other disorders of the vasculature: varicose veins, phlebitis, and auto-immunological attacks on the vessel walls, such as arteritis. (Out of the Earth, Simon Mills, pg. 406)
Linden flower tea combined with rose petals can be called upon to help calm a person's spirit and reduce nervous tension and unrest, headaches, mild palpitations, and shortness of breath. In Traditional Chinese Medicine these symptoms are considered to be a constraint of the heart chi or liver yang rising. If symptoms persist, it is important to seek out a holistically minded health care professional. Warm baths with a tea or with pure essential oils of linden, lavender and rose added is also deeply relaxing and restorative to one's spirit.
As when using any new herb, best to first try it alone and in small doses. There are no known contraindications for linden flowers, though there is always a chance a person can have an allergic reaction to a plant.
Please consider planting a row of linden trees, for the bees and for herbalists who may be looking for local sources of fresh and dry flowers and leaves. At Avena Botanicals, we are finding it harder to obtain certified organic linden that is domestic or European. It appears that the Chinese are beginning to grow Linden for the international market and crowding out the once available European linden. If you are in a more urban setting or are looking to plant a hedgerow along a road or drive, consider planting the Tilia europea or T. cordata species. The more hardy, nectar producing perennial trees and shrubs we can plant, the happier and healthier our pollinator friends and our planet as a whole will be.