Sweet Woodruff Plants

You Can Grow This Ground Cover Under Trees

Sweet woodruff (image) performs well under trees. I grow mine under a Kwanzan cherry tree.
Sweet woodruff can perform just fine under trees. David Beaulieu

Taxonomy, Geographical Origin of Sweet Woodruff

Plant taxonomy classifies sweet woodruff plants as Galium odoratum. The species name or "specific epithet," odoratum is descriptive of the plant's aromatic quality. A related plant (which grows wild in regions such as New England, U.S.) is Galium mollugo (wild madder). Both are Old-World natives and can also go by the common name of "bedstraw" (see below). In fact, the plant family to which they belong, Rubiaceae, is commonly known as the bedstraw family.

Plant Type, USDA Plant Hardiness Zones

These are herbaceous plants and perennials, botanically speaking. In terms of use, they are treated as herbs (see below) and/or as ground covers

Sweet woodruff plants are cold-hardy enough to be perennials as far north as planting zone 4. Their southern limit is typically listed as zone 8.

Characteristics, Sun and Soil Requirements

These ground covers bear clusters of small, white, star-shaped flowers and reach 8-12 inches in height (with a slightly greater width). In USDA plant hardiness zone 5, for example, they will bloom in early May. The foliage is aromatic and takes the form of whorls of lance-shaped, dark green leaves. This is a deer-resistant ground cover. Fortunately, deer pests are often repelled by smells that we humans enjoy. It is also one of the rabbit-proof flowers.

This herb prefers shade and a well-drained, slightly acidic, soil. Sweet woodruff plants will grow more vigorously with regular watering, but this will also result in their spread (perhaps to areas where they are not welcome). If you wish to keep sweet woodruff contained within a certain space, cut back on watering.

Uses in Landscaping and Beyond

Use sweet woodruff plants as a flowering ground cover for shady areas in the landscape. These perennials will spread out to form a mat that, in conjunction with landscape mulch, will help choke out weeds. They are one of the plants that grow well under pine trees.

They will even grow under a black walnut tree (despite the toxicity given off by the latter), whereas many plants fail to grow well under black walnut due to a chemical emitted by this tree: juglone.

However, sweet woodruff's usefulness doesn't end when the growing season ends. Traditionally, sweet woodruff herbs have been commonly harvested and used for medicinal and culinary purposes. For example, the fresh leaves have been used medicinally to heal wounds. According to the UNC Health Sciences Library, sweet woodruff is used in Germany to flavor beers and wines (for example). The dried vegetation was once used to stuff beds; thus the alternate common name, "bedstraw."

Nowadays, we more often value this herb as a fragrant plant. It is dried and used to lend a fragrance to linens, sachets and potpourris. You could also use the dried leaves and stems to make a fragrant wreath.

Caveat in Growing Sweet Woodruff and More About the Fragrance

With its ability to spread by means of stolons, sweet woodruff can be invasive. However, it will not spread much if grown in dry soil. Since many plants perform poorly in dry shade, this sturdy customer offers a solution for spots on the landscape plagued by such conditions. Sometimes, it pays to have a plant tough enough to be considered potentially invasive working on your side.

The intensity of the fragrance of sweet woodruff's foliage increases when dried, and its aromatic quality lasts for years. It is, consequently, a favorite in craft projects using dried plant material ranging from potpourris to kissing balls. The fragrance of sweet woodruff herbs has been variously described as resembling newly-mown hay or vanilla.

For optimal fragrance, harvest the leaves of sweet woodruff right after the plants bloom. The harvested branches can be tied in bunches and hung in a warm, dark place with low humidity to dry.