How to Plant and Grow Sweetgrass

Sweetgrass is an aromatic perennial prairie grass prized for its fresh scent. It is native to northern Europe and a wide geographical range in North America, naturally occurring in moist, cool meadows and along stream banks. Sweetgrass blooms between March and May, which is much earlier than most grasses. After the bloom, it forms small spikelets of bronze seedheads. 

Sweetgrass is considered sacred by many indigenous peoples in North America. Native Americans have long used sweetgrass for making smudge sticks as well as for weaving baskets. The characteristic sweet smell of the grass comes from coumarin, a natural anticoagulant. 

Due to its prolific spread by rhizomes—up to 2 feet annually—the grass should only be planted in large landscapes or in settings where it can be confined. It eventually forms a thick mat of foliage that tends to flop over unless cut back.

Where to Plant Sweetgrass

Plant sweetgrass in a location with full to partial sun and consistently moist soil that is slightly acidic to neutral.

Select a location with conditions that mimic the natural habitat of the grass in wet meadows, low prairies, and the edges of sloughs and marshes. Sweetgrass works well for erosion control on moderately sloping hillsides and embankments.

Keep in mind that because of its aggressive growth by rhizomes, sweetgrass will be difficult to remove once it is established and has spread to areas where you don’t want it.

Mass plantings or drifts create the best effect. Sweetgrass blends in handsomely with other low-growing ornamental grasses or tall perennials.

How and When to Plant Sweetgrass

Plant nursery-grown sweetgrass in pots in the spring. Dig a hole at least twice the diameter of the nursery pot and just as deep. Place the plant in the center of the hole and backfill with original soil. Tamp down the soil and water immediately to remove any air pockets. Continue watering the new plant regularly in the absence of frequent rain. The soil should be wet to moist at all times.

Space plants 2 feet apart.

Sweetgrass Care Tips

If provided with sufficient moisture, sweetgrass is a vigorously growing, tough native grass that needs only minimal care.

Light

Sweetgrass needs at least half a day of full sun to flourish.

Soil and Water

Although sweetgrass prospers in rich, loamy, loose soils, it grows in almost any soil, including sandy and clay soil as long as it’s moist to wet. The ideal pH range is 6.0 to 8.0.

Consistent moisture is essential to successfully growing sweetgrass. The soil should never be allowed to dry out. If the soil is not naturally wet, establish a regular watering schedule, especially during dry periods.

Temperature and Humidity

This is a very hardy cool-season grass that grows as far north as Alaska and Newfoundland. It does not have any known issues with low or high humidity.

Fertilizer

Don’t fertilize the grass in the first year after planting, as it would merely encourage weed growth around the plants. In the second year, apply a nitrogen fertilizer for cool-season grasses once in the spring when the grass emerges from its winter dormancy, and again in late summer or early fall, about six weeks before your average first fall frost.

Pruning

Pruning is typically not necessary, but for a neater appearance, cut the old foliage back close to the ground in the early spring to make room for new growth. If the grass gets so tall that it starts to flop over, cut it back once or twice during the growing season.

Potting and Repotting Sweetgrass

Sweetgrass looks best planted in the landscape but if you have a small space, container growing is recommended to keep its growth under control.

Choose a container with large drainage holes at least 12 inches wide and deep. Fill it with a combination of well-draining potting soil and compost. Keep in mind that potted plants need more frequent watering—daily in hot summer weather—because the soil in containers heats up more and dries out much faster than garden soil.

Despite sweetgrass being winter-hardy in areas with subzero winters, growing it in containers exposes its roots to frost and freeze-and-thaw cycles. The containers should remain outdoors during the winter but you need to protect the roots by burying the container in the ground or insulating the roots and placing the pot in a second, larger pot to create a planting silo.

When the grass has outgrown its pot, repot sweetgrass to a larger container or divide it.

Pests and Problems

Sweetgrass is mostly free of serious pest and disease issues. The plants are attractive to mealybugs, slugs, and snails, as well as rabbits and groundhogs.

How to Propagate Sweetgrass

Propagating sweetgrass from seed is not recommended because of low germination rates. Propagating plants by division has a better success rate. In the spring, dig out a clump and divide it into smaller sections. Make sure each section has rhizomes or rhizome buds on it.

Plant the sections at the same height as the original plant. Cut the leaves to a height of 3 or 4 inches, which encourages root development and reduces moisture stress. Water it well right after planting and continue to water regularly until the grass is established.

Sweetgrass Companion Plants

American Burnet

This easy-to-grow perennial with a loose, open habit is native to the northeast and northwest of North America. American burnet is listed as a threatened or endangered species in nine U.S. states so by planting it in your yard, you help preserve this native plant species. The upright, tall, bottlebrush-like flower spikes are white or pale green and appear from August through October. A plant for meadows and naturalized planting areas, it pairs well with ornamental grasses and other native flowering plants. Zone 4-8

Cardinal Flower

Colorful lobelias thrive in any location where the soil is consistently moist, which makes them a great choice for landscaping around ponds and streams. Lobelia even loves downright wet conditions. A gardener’s favorite is the cardinal flower (Lobelia cardinalis), a species native to North America with upright 3-foot stems clothed with 3- to 4-inch-long, lance-shape dark green leaves. The brilliant red flowers are borne in loose spires. Zone 2-8

Penstemon

Penstemons are tough perennials that stand up to intense growing conditions. From dwarf alpine plants to prairie penstemons reaching up to 5 feet tall, there's a height for every part of the garden. Along with their bright blooms, many varieties of penstemon also have colorful foliage to add to the mix. Zone 3-9