Blue lyme grass | The Morton Arboretum

Family (English) Grass
Family (botanic) Poaceae
Tree or plant type Grass, Perennial
Native locale Non-native
Size range Large plant (more than 24 inches)
Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
Hardiness zones Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9, Zone 10
Soil preference Moist, well-drained soil
Tolerances Alkaline soil, clay soil, Dry sites, Occasional drought, Road salt, Wet sites
Season of interest early summer, midsummer, late summer, early fall
Flower color and fragrance Other
Shape or form Arching

Size and Form:

Blue lyme grass can grow up to 3 feet tall, but the habit is often floppy, which makes it appear shorter.

Native geographic location and habitat:

This plant is native to Europe.

Leaf or needle arrangement, size, shape, and texture:

The leaves are about 1/2 inch wide and up to 18 inches long. They have a distinct blue to blue-gray color and may briefly change to yellow before going dormant.

Flower arrangement, shape, and size:

The tiny flowers produced in blue-green spikes occur in mid-summer.

Fruit, cone, nut, and seed descriptions:

The small fruit (caryopsis or grains) are held in a narrow spike that matures to beige. They are not very showy.

Plant care:

Blue lyme grass prefers full sun or light shade. It can tolerate a wide range of soil conditions and is also salt tolerant. Since it is a cool season grass, most of its active growth occurs in spring and fall. In cold regions, it will be completely dormant instead of semi-evergreen in winter. Blue lyme grass may be mowed down in fall or late winter.

List of pests and diseases:

This plant doesn’t have any serious pest problems. Blue lyme grass can be an aggressive grower as it is a running grass which spreads by rhizomes. In Wisconsin, it is considered invasive.