Sweet Woodruff - Asperula odorata

Common Names: Sweet Woodruff, Asperula odorata, Wild Baby's Breath, Master of the Woods, Waldmeister (German), aspérule odorante (French), galii odorati herba, marunka májová, Petit Muguet, Reine des Bois, Marynka, božec, mayflower, bed straw, sweet scented bedstraw, mařinka, woodruff, maitrank, may wine herb, planá mořena, mořenka

Latin Name: Galium odoratum (dříve Asperula odorata)

Origin: Asia, Europe

Short Introduction

This plant prefers partial to full shade and thrives in moist, humus-rich, fertile soil with regular watering. Propagation can be achieved through crown division, cuttings, or separating the root system. It grows easily from seed or by planting vegetative runners, ideally spaced about 25 cm apart. Sweet Woodruff often flourishes where other plants struggle to bloom. It can also be cultivated in larger containers, but open space is preferable to help prevent root rot.

Harvest is focused on the above-ground parts just before flowering or at the turn of May and June, around midday. Drying should be as rapid as possible using artificial heat up to 35°C (95°F). Properly prepared herbal material retains the color of the fresh plant, has a slightly bitter taste, and carries the characteristic coumarin fragrance. It is best stored in well-sealed, dark glass containers with limited exposure to humidity and sunlight.

Detailed Description

As old herbals say, 'it opens blocked livers and refreshes the heart,' and it has traditional uses for supporting digestion, calming, and promoting restful sleep.

Botanical Information

Sweet Woodruff (Asperula odorata) is a perennial herb growing between 10 and 50 cm tall. It features a square stem with whorls of simple, smooth, elliptical to lance-shaped leaves (2–5 cm long) with rough margins, arising from a weak, creeping, and branching rhizome. At the tip of the stem are clusters of small, white, tubular bell-shaped flowers with four-lobed corollas, 4–7 mm in diameter. The plant blooms from May to June. The fruit is an oval, 2–4 mm schizocarp covered in tiny hooks that cling to passing people or animals.

Origin and Distribution

Sweet Woodruff is native to much of Europe, prevalent from Spain and Great Britain in the west, southern Scandinavia to Russia, and further east through western Siberia to Turkey, Iran, the Caucasus, China, and Japan. It has also become naturalized in parts of North America, specifically the USA and Canada, where it thrives.

Sweet Woodruff commonly forms dense carpets in deciduous woodlands. The plant prefers shady deciduous forests (beech, hornbeam-beech, etc.) with acidic to slightly alkaline, moist, humus-rich, and loose soil, along clearings and forest paths. In the Czech Republic, it is typically found in foothills and scattered hedgerows.

Usage / Dosage

True to its name, Sweet Woodruff emits a pleasant and very aromatic scent attributable to its coumarin content, which persists even after drying. Owing to its intoxicating aroma, it is used in liqueur and alcoholic beverage production. In Germany, it flavors May wine (Maibowle), punch, brandy, jam, and Berlin beer. In Switzerland, it is added to Benedictine liqueur; in France, to champagne; and in Scandinavia, to sausages and meat products.

Historically, Sweet Woodruff has been valued as a sedative, antispasmodic, diuretic, and for imparting sweet flavors. In homeopathy, it is used therapeutically for liver disorders and smooth muscle cramps, mainly in the digestive tract. Some modern herbal approaches leverage the potential of Sweet Woodruff's constituents to stimulate appetite.

The herb is particularly popular among patients with insomnia, sleep issues, hysteria, restlessness, and sensitive nervous systems. Numerous papers document the beneficial effects of Sweet Woodruff’s bioactive compounds for those experiencing sleep deficits and difficulty falling asleep.

Three in vivo studies examined Sweet Woodruff's constituents in supporting the healing process, highlighting marked epithelializing and antioxidant effects. Other constituents have demonstrated antioxidant and additional anti-inflammatory (by inhibiting pro-inflammatory factors) activity in vitro. The plant's anthraquinone derivatives have shown an inhibitory effect on the thymidine kinase of herpes simplex virus, thus granting an antiviral effect.

The plant's phenolic compounds—including coumarins, flavonoids, and tannins—are noted as core groups of secondary metabolites with strong antimicrobial activity. Tannins benefit antibacterial, angiogenic, and antioxidant activity through several mechanisms and also provide astringent and epithelial support. Coumarins can reduce swelling, offering anti-inflammatory benefits by breaking down extracellular protein accumulations and suppressing prostaglandin synthesis.

Flavonoids further exhibit anti-inflammatory action through strong antioxidant activity, neutralizing free radicals in cells. In vivo, plant flavonoids have shown antioxidant effects by regulating inflammation-affected cells. Additionally, their ability to reduce lipid peroxidation may protect against cellular damage, necrosis, while promoting vascularization, improved circulation, and collagen formation and function.

Coumarins and flavonoids have been independently tested in animals for treatment and prevention of venous wall protection in cases of phlebitis and hemorrhoids with positive outcomes. These compounds also show potential for treating varicose veins and have documented antibacterial effects.

Constituents such as asperuloside and related derivatives have shown anti-inflammatory action in in vivo studies. In another animal study, induced minor inflammation on the paws was treated with either placebo, Sweet Woodruff extract, or indomethacin (a reference anti-inflammatory compound). Indomethacin reduced inflammation by 45%, and Sweet Woodruff extract by 25%.

Traditional Uses

In folk medicine, Sweet Woodruff has long been and continues to be used for sleep problems, calming the nerves, and as a topical for minor skin injuries and purulent wounds. Externally, it is also applied for migrainous or difficult to localize headaches. Through fermentation, Sweet Woodruff can yield dicoumarol, a compound that thins the blood by reducing its coagulability, which may benefit the treatment of thrombotic events, vein inflammation, complicated hemorrhoids, or after acute conditions.

Herbalists, drawing on traditional knowledge, describe the plant as a diuretic, helpful for digestive complaints including stomach pains, bloating, kidney stones, cramps, pulmonary inflammations, palpitations from stress, hysteria, and nervous origin problems. Modern herbalists often recommend Sweet Woodruff as a mild laxative for non-serious constipation and as an anti-inflammatory for arthritic knee pain.

Safety and Limitations

The herb should not be administered chronically due to a risk of causing headaches or vomiting. Moderate, short-term use is advised. Sweet Woodruff is not recommended in conjunction with anticoagulant therapy as it may increase the risk of drug interactions; for this reason, it is best to stop using Sweet Woodruff about two weeks before planned surgery. There is no available safety data for use in children under 18 years.

Active Compounds

Chemical analysis reveals more than 225 compounds in the herb, which may not be the final count. The above-ground parts contain mainly coumarin glycosides (specifically 0.4–1.0% coumarin), tannins, bitters, essential oil, organic acids, vitamin C, nicotinic acid, the terpene glycoside asperuloside (0.05–0.30%), monotropein (0.04%), iridoids, anthraquinones, and flavonoids such as rutin, fisetin, quercitrin, hesperidin, chrysin, catechin, and epicatechin.

Traditional Dosage

No official literature details an ideal dose for adults. Some sources describe using 15–30 g of dried, or slightly more fresh, herb steeped in 3 cups of liquid for about 10 minutes. Sweet Woodruff tincture is prepared by mixing about 50–80 g of the herb with 250–300 ml alcohol and 800–1000 ml water.

To make Sweet Woodruff punch, 1.5 teaspoons of dried herb are soaked in apple cider for several hours, then strained and chilled. Half a teaspoon of the herb may be infused in milk with honey for 1–2 hours, then strained and cooled. For May wine, 10 g of the herb is mixed with 0.5 liters of white wine, sugar, and orange, and left to infuse for about 12 hours.