Sweet Woodruff: A Sweetly-Scented Groundcover That Adds Texture in Your Shadiest Garden Corners (2024)

Sweet woodruff makes a big statement in almost any shade garden. For one, the low-growing groundcover is adorned with tiny white blossoms each spring. For another, the foliage and flowers bear a sweet, grassy, vanilla-like fragrance often compared to fresh-cut hay. Sweet woodruff is a coffee (Rubiaceae) family member and an herbaceous perennial hardy in zones 4-9. It is a popular lawn alternative and needs little sunlight to thrive in tricky spots (like under trees or shrubs) where other plants may struggle.

Where to Plant Sweet Woodruff

Sweet woodruff is a mat-forming plant that makes an excellent groundcover beneath trees or in cool, low-light garden spots. The easy-to-grow perennial can even thrive in the understory of black walnut trees—which is notable because black walnut trees produce a chemical (juglone) that harms or kills other plants. Sweet woodruff is unbothered.

Sweet woodruff is often used as a quick-spreading groundcover in cottage and rock gardens. It grows beautifully between stepping stones or along a dry creek bed or the border of a path. The shallow-rooted perennial also offers natural erosion control, which makes it excellent for meadowscapes, naturalized areas, and slopes.

Sweet woodruff is not classified as invasive but can grow aggressively in moist, loamy soil. If control is a concern, know that the woodland garden favorite is best behaved in moderately dry shade.

How and When to Plant Sweet Woodruff

The most efficient way to grow sweet woodruff is to start with nursery-grown plants in early spring. After the danger of frost has passed, loosen the soil and dig a hole slightly wider than your plant's root ball. Place the plant in the hole and replace the displaced soil. Tamp the soil down gently to remove air pockets and water well. If planting more than one sweet woodruff plant, place them 10 to 12 inches apart.

Sweet Woodruff Care Tips

Sweet woodruff is an herbaceous perennial native to Europe and North Africa. It grows quickly and easily in full to partial shade, forming a carpet of tiny white blooms over starburst-shape leaves in early May. The aromatic groundcover requires little care but does not tolerate drought.

Light

Sweet woodruff prefers full to partial shade. It can tolerate some sun exposure but may go dormant or perish in hot summer months. In full sun, the soft, aromatic leaves may also scorch.

Soil and Water

Sweet woodruff thrives in moist, loamy, well-drained soil that is slightly acidic (6.0 to 6.8 pH), but tolerates a wide range of soils. Sweet woodruff will also grow in clay or sandy soils (but less prolifically).

The fast-spreading, shade-loving groundcover likes medium to wet soil and may go dormant if the soil dries out. If you want to encourage growth, water your sweet woodruff whenever the top inch of soil feels dry.

Temperature and Humidity

Sweet woodruff prefers cool shade and average humidity but can tolerate a wide range of climates. It fares best in temperatures between 68˚ and 95˚ Fahrenheit. Prolonged exposure to high temperatures (or sun) may cause bleaching, sunburn, curling, or early dormancy. In extreme cases, the plant may wilt and die. Extreme cold (below 0˚) may diminish flowering and sprouting the following year.

Fertilizer

Sweet woodruff does not require fertilization, but an annual feeding with a balanced slow-release fertilizer in early spring will accelerate growth in poor soil.

Pruning

Sweet woodruff does not require pruning. It does, however, spread easily via rhizomes and seeds. Left unchecked, it may grow aggressively and overwhelm other plants. To reduce spreading, hand pull unwanted growth or mow your sweet woodruff with sharp blades set on high. If pulling, loosen the soil around the roots to remove the rhizomes. Otherwise, the delicate stems can easily snap and leave the roots behind to grow again. Mowing will not eliminate established sweet woodruff, but it will keep it from spreading.

Potting and Repotting

Sweet woodruff can be grown in containers and makes a pretty companion plant for larger potted perennials, shrubs, or trees. Just be sure to pair it with plants that prefer moist to moderately wet, well-drained soil.

Plan to repot and/or divide container-grown sweet woodruff every 2 to 3 years in the spring. Dig around the edges of the plant and loosen the soil to pull up the entire plant without damaging the root system. Use your fingers to divide the plant into 2 or 3 smaller sections, each with a healthy set of roots and shoots. Replant each section and water well.

Pests and Problems

Sweet woodruff isn’t prone to issues with pests and diseases but can have issues with leaf spot, rust, and powdery mildew. Slugs can also be a nuisance but are easily deterred with a sprinkling of diatomaceous earth.

How to Propagate Sweet Woodruff

The most efficient way to propagate sweet woodruff is via division. In the spring or fall, carefully dig around your plant. Loosen the soil to lift the plant without damaging the root system. With your fingers, separate the plant into 2 or 3 sections, each with a viable set of roots and shoots. Replant the sections at least 10 to 12 inches apart.

Seed propagation, on the other hand, produces less consistent results. For best results, sow sweet woodruff seeds directly in the ground in early spring and cover them with a layer of peat moss. Keep the soil evenly moist and cross your fingers for germination. Or, start your seeds indoors (at least 10 to 12 weeks before the last frost date) with a period of cold stratification. Sow the seeds in a seed-starter mix and keep them at room temperature for 2 weeks. Cover them and refrigerate them for 4 to 6 weeks. During the cold stratification, keep the soil evenly moist. Next, bring the seeds back to room temperature (while still in their seed-starter mix) and allow them to germinate for 2 to 4 months. If successful, plant your seedlings outdoors after the danger of frost has passed.

Companion Plants for Sweet Woodruff

Columbine

Perfect for cottage and woodland gardens, columbines are available in a rainbow of colors. Some, like western columbine (Aquilegia formosa) and eastern red columbine (Aquilegia canadensi) are even native to North America. Columbine flowers resemble folded paper lanterns and attract pollinators—especially hummingbirds—from far and wide. Columbine thrives in sun or partial shade in moist, well-drained soil (in zones 3-9). The plants are short-lived but self-seed readily. To prevent self-seeding, deadhead your columbine plants after they bloom.

'Dutchman's Breeches' Bleeding Heart

'Dutchman's Breeches' bleeding heart (Dicentra cucullaria) is a perennial (hardy in zones 3-9) native to the shady woodland environment of the eastern United States. It has distinctive bloomer-like blossoms which give it its amusing name (and make iteasy to recognize). Like sweet woodruff, this spring flower likes consistently moist, well-drained soil. It prefers cool areas with partial to full shade and protection from the harsh afternoon sun.

Hakone Grass

The graceful, bamboo-like stems and soft green blades of Hakone grass bring color and elegance to shade garden spots. The perennial prefers partial shade and moist,well-drained soil with a pH between 6.0 and 7.0. It is largely unbothered by diseases and pests (even deer) and makes a tough, drought-tolerant plant for landscape edging in zones 5-9.

Hosta

Hostas are among the easiest plants to grow and come in a range of foliage shapes, colors, textures, and sizes. To successfully grow hostas, you need shade; rich, loamy, well-drained soil; and ample rainfall. Once established, however, they are a breeze to maintain (in zones 3-9). This tough, shade-loving perennial (sometimes known as plantain lily) also blooms with flared white or lavender flowers in summer.

Virginia Bluebell

Virginia bluebells, native to eastern North America, are woodland garden beauties with blue, bell-shape flowers that open above bright green foliage in midspring. Like sweet woodruff, Virginia bluebell (Mertensia virginiana) grows best in part shade and moist soil (in zones 3-8). In ideal conditions, they will reach their flowering potential in late spring—often before the trees have begun to flower and leaf out.

Canadian Wild Ginger

Like sweet woodruff, Canadian wild ginger(Asarumcanadense) is a low-growing plant that thrives in moist, shady places (in zones 3-8). Unlike sweet woodruff, Canadian wild ginger is native to North America. This stemless plant bears dark green heart-shape leaves with visible veining and sneaky cup-like purple-brown flowers that hide beneath the foliage. Wild ginger spreads slowly by rhizomes to create a lush groundcover inmedium to wet, well-drained soil.Primarily grown for ornamental use, wild ginger is not a relative of culinary ginger. However, its roots have a strong ginger-like odor.