Lyme Grass, Leymus arenarius: “Blue Dune Grass”
Lyme grass is the rare plant that can be described as “aggressive” and still be useful in a garden setting. Of course, you have to choose it to play a specific role in a thoughtful landscape design, and plant it in the right environment.
If you’re not sure this vigorous semi-evergreen grass is right for you and your garden, please keep reading to learn more.
![Lyme grass growing in Southport, England. Photograph by Len Worthington via Flickr.](https://media.gardenista.com/wp-content/uploads/2019/01/lyme-grass-leymus-arenarius-bill-worthington-flickr-733x977.jpg)
Formerly known as Elymus glaucus, lyme grass also has many other names including sea lyme grass, blue lyme grass, and sand wild rye. Native to northern Europe, this 2-to-3-foot-tall grass has incredibly beautiful steel-blue, arching foliage. In the summer, sturdy narrow blue-gray flower spikes shoot up. Later in the season, they turn tawny.
The downside? This densely tufted clumping grass spreads aggressively by rhizomes and can be a total nuisance in the wrong setting.
![Landscape architect Scott Lewis incorporated lyme grass in a palette of mixed ornamental grasses. See more in Vineyard Haven: A Napa Valley Garden That Belongs to the Land.](https://media.gardenista.com/wp-content/uploads/2015/11/scott-lewis-vineyard-retreat-grasses-northern-california-10-gardenista-733x1096.jpg)
So the question remains, how do you use lyme grass smartly? Specific situations that may call for lyme grass include: erosion control, to stabilize sand dunes, or as a wide-spreading, fast-growing ground cover in sunny areas. (Of course, Leymus arenarius is also welcome in planters and containers where its wily nature can be corralled. Tip: This grass tends to be less pesky in dry, clay soils.
![Photograph by dan.kristiansen via Flickr.](https://media.gardenista.com/wp-content/uploads/2019/01/lyme-grass-leymus-arenarius-dan-kristiansen-flickr-733x489.jpg)
The variety ‘Blue Dune’ has equally as dramatic steel-blue foliage and also produces wheat-colored summer plumes. ‘Blue Dune’ spreads quickly by rhizomes but is useful for stabilizing steep slopes or filling a large sunny to partly sunny area very quickly. Space 2-3′ apart as a ground cover or closer for quicker coverage.
![Photograph by Kristian Peters via Wikimedia.](https://media.gardenista.com/wp-content/uploads/2019/01/leymus-arenarius-sand-beach-kristian-peters-wikimedia-733x550.jpg)
Cheat Sheet
- Lyme grass is salt, heat and very drought-tolerant.
- The flowers of lyme grass attract butterflies but the foliage is deer and rabbit-resistant.
- Foliage of lyme grass is great in floral arrangements.
- This cool-season grass produces year-round interest where it remains evergreen in mild winter areas, including in USDA growing zones 3 to 9.
- Keep this grass out of perennial beds and instead think of massing it in large areas that need a ground cover, on sand dunes, or in containers.
![Photograph by Sten Porse via Wikimedia.](https://media.gardenista.com/wp-content/uploads/2019/01/leymus-arenarius-sten-porse-wikimedia-733x469.jpg)
Keep It Alive
- Lyme grass tolerates a wide range of soils from wet to dry.
- Plant this ornamental grass in full sun to part shade.
- Cut back or mow the foliage to the ground in the fall.
- Divide clumps of lyme grass from mid-spring to early fall.
For more growing tips see Lyme Grass: A Field Guide to Planting, Care & Design in our curated guides to Grasses 101. Read more about how to harness the powers of ornamental grasses in a landscape:
- Leaves of Grass: 9 Ways to Create Curb Appeal with Perennial Grasses
- Gossamer Gardens: 11 Ideas for Landscaping with Mexican Feather Grass
- Expert Advice: 8 Tips for a Meadow Garden from Grass Guru John Greenlee
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