Leymus

( LAY - muss )

At-A-Glance Information

This genus of perennial grasses, known commonly as Wild Rye or Lyme Grass, includes specie which need full sun to light shade and little to moderate water to perform well in the landscape. They are valued for their silvery blue to greyish foliage and are very drought tolerant. They will stay green all year with regular summer waterings and die back in winter in temperate or cooler regions. These grasses are used as erosion control and dune stabilization, or as foliage and color contrast in mixed beds and borders in water-wise landscapes.

leymus Species and Varietals

Leymus is a member of the plant family Poaceae and includes 40-50 distinct species. Plants in the genus are closely related to those in Elymus. The best growing zones for Leymus vary depending on the species. For more information, see the species descriptions below. To find your zone, click here: Zone Map.

Leymus arenarius (Elymus arenarius) (Blue Lyme Grass, European Dune Grass, Sand Ryegrass)
This species grows well in USDA hardiness zones 4-9 or Sunset growing zones A2, A3, 1-9 and 14-24, and is native to coastal northern and western Europe. It forms a low clump (to 2-3 feet tall) of blue-gray leaves topped with relatively inconspicuous flowers. Cultivars include 'Blue Dune' (with especially silver-blue leaves) and 'Glaucus' (the straight species). This species is considered highly invasive in the Great Lakes region as well as New York, and Connecticut in the United States, and Canada (mainly in Ontario and Quebec).

Leymus condensatus (Giant Wildrye, Giant Rye Grass)
Best in USDA hardiness zones 7-10 or Sunset growing zones 7-12 and 14-24, and native to coastal Southern California and the Channel Islands. This species has green leaves and reaches 9 feet tall and 6 feet wide when in bloom. Spreads slowly by rhizomes. Cultivars include 'Canyon Prince' (to 4 feet tall and 3 feet wide with green new foliage) and 'Gaviota Gray' (to 4-5 feet tall with large flower spikes).

Caring for Leymus

Before planting these shrubs, consider installing a root barrier that reaches to 18-24 inches deep to prevent their aggressive root system from spreading in the garden or damaging hardscapes. Leymus, or Wild Rye, should be planted in a space in the landscape that receives full sun. Ensure that soil is well-draining, moderately fertile, and has a pH of between 5.0 and 9.0 (acidic to alkaline). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these grasses are considered drought-tolerant, able to get by on rainwater alone for much of the year with supplemental waterings during extended periods of drought.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants or leave them over the winter months for added interest. Leymus grasses are perennials that take about 2 to 5 years to mature, and will spread in the garden. They can live for about 10 years under ideal growing conditions before needing to be replaced, and their spreading habit will provide new plants for the garden indefinitely.

Caring for Leymus in Containers
Container cultivation is a great way to enjoy the beauty of these plants while curbing their aggressively spreading roots. Choose a container that is at least 12-14 inches wide. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Leymus plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Leymus plants are best propagated via division. These plants will also re-seed freely in the landscape, providing seedlings that can be dug up and transplanted elsewhere. To propagate your Wild Rye by division of existing plants, follow the instructions below:

Propagating Leymus by Division
To propagate via division, you will need a clean shovel, clean pruning saw (optional), extra pots if you are not going to immediately plant your divisions in the ground, and well-draining soil to fill the pots. To propagate your Wild Rye by division, follow the steps below:

In early fall or early springtime, identify the area of plants you're going to divide. Start by loosening the soil around the plant with your shovel, working your way inward to avoid causing damage to the bulbs. Once you've gotten your clump out of the ground, run water over it or simply shake it to remove excess dirt. Then, lay it out on its side.
Separate the clump into multiple pieces, each with a healthy root system and adequate above-ground growth.
Prepare the planting area, whether it is a container or bed in the garden, and then plant the divisions. Afterwards, resume regular care.

Problems and Pests

Certain Leymus species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Leymus grasses can be susceptible to developing issues with the following pests and diseases in the landscape: