How to Grow Lyme grass

iNaturalist

Lyme grass

Leymus secalinus

grass

Lyme grass is a perennial cool-season grass native to coastal dunes and sandy areas of North America. It features blue-green foliage and distinctive spike-like flower heads, growing 2-4 feet tall. This hardy grass is valued for erosion control, landscaping, and wildlife habitat restoration.

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Example Lyme grass timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Lyme grass

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Lyme grass

    Around Aug 15

    ≈ 120 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Lyme grass dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6+ hours daily; tolerates partial shade
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Water: Moderate water needs once established; prefers drier conditions; drought tolerant; water regularly during first growing season to establish deep roots
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Spacing: 12-18 inches apart for clump spacing inches
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Days to maturity: 120-180 days from seed to mature clumps
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Planting depth: Surface sow or press into soil; needs light for germination

Soil

Type: Well-draining sandy or loamy soil; tolerates poor soil conditions
pH: 6.0-7.5
Amendments:
Sand or grit for drainage Organic matter to improve moisture retention

Growing Zones

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Thrives in zones 3-8, with best performance in cool to temperate regions

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a

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Growth Stages

1

Germination

10-14 days

Seeds begin sprouting and develop first true leaves

Keep soil moist but not waterlogged; ensure adequate light exposure; germination takes 10-14 days

2

Seedling/Establishment

4-6 weeks

Young plants develop multiple shoots and begin forming shallow root systems

Water regularly to keep soil consistently moist; protect from competition; thin if overcrowded

3

Vegetative Growth

8-12 weeks

Plant develops dense clumps of blue-green foliage; rhizomes expand underground

Reduce watering frequency as plant becomes established; allow soil to dry between waterings; minimal fertilization needed

4

Flowering

4-8 weeks

Distinctive spiky flower heads emerge, typically pale yellow to tan in color

Maintain dry conditions; avoid fertilizing; allow flowers to mature naturally; dead-heading is optional

5

Maturity/Dormancy

4-6 months

Foliage takes on golden or bronze tones; plant enters dormancy in winter

Reduce watering significantly; no fertilization needed; can cut back dead foliage in late winter or early spring

Companion Planting

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Plant with:

Avoid planting near:

Aggressive spreading grasses Dense shade-creating trees

Common Pests

  • Remove affected foliage; use neem oil spray if severe; encourage natural predators

  • Spray with horticultural oil; prune affected stems; improve plant vigor through proper watering

  • Ensure good air circulation; avoid overhead watering; remove heavily infected foliage

Uses

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Erosion Control & Dune Stabilization

Household

Lyme grass is extensively used to stabilize sand dunes and prevent coastal erosion due to its strong rhizomatous root system. Its ability to trap sand and build dunes makes it invaluable for beach restoration projects. [source]

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Wildlife Habitat

Wildlife

The plant provides shelter, nesting material, and food sources for various coastal bird species and insects. Its dense growth creates microclimates beneficial for small mammals and insects. [source]

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Ornamental Landscaping

Craft

Prized in native plant gardens and xeriscaping for its attractive blue-green foliage and architectural flower heads. Works well in drought-tolerant landscape designs and coastal gardens. [source]

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Traditional Herbal Use

Medicinal

Some coastal indigenous cultures traditionally used related Leymus species for medicinal purposes, though modern research is limited. Historical uses included treating respiratory and digestive ailments. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Lyme grass is not harvested for consumption. For erosion control or transplanting, divisions can be taken in spring or fall. For seed collection, allow flower heads to mature and dry completely, then harvest seeds in late summer or early fall.

Fun Facts

  • 🌱 Lyme grass is sometimes called 'lime grass' due to a historical naming confusion, though it has no connection to the citrus fruit or the chemical compound lime.
  • 🌱 The plant's rhizomes can extend several feet horizontally underground, making it extremely effective at trapping sand and preventing erosion in coastal environments.
  • 🌱 Lyme grass was historically used in coastal management programs along the Atlantic and Pacific coasts of North America, and many beach restoration projects still rely on this species today.

Gardening Terms

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