Blue Rug Juniper (Juniperus horizontalis 'Monber')

Blue Rug Juniper

Juniperus horizontalis 'Monber'

Low, dense mat of silvery-blue foliage, a living carpet for slopes and rock gardens. Evergreen groundcover shrub; common name: Blue Rug Juniper.

Full sun
1–2/week
Beginner
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Plant Needs

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Sunlight Full sun exposure is required to maintain the cultivar's signature silvery-blue foliage; tolerates light partial shade with reduced color intensity
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Watering Water deeply but infrequently, allowing the top 5–10 cm of soil to dry completely between waterings to prevent root rot
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Temperature Extremely cold hardy, surviving temperatures as low as -40°C; tolerates hot, dry summers with proper drainage
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Characteristics

  • Leaf: Scale-like, silvery-blue foliage tightly packed in overlapping rows along trailing stems
  • Stem: Prostrate, trailing stems that root at nodes to form dense, spreading mats
  • Fruit: Small, round, blue-black berry-like cones produced only on female plants
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Care Guide

Watering

Water every 7–10 days during prolonged dry spells; reduce frequency if natural rainfall is sufficient

Fertilization

Apply a balanced, slow-release fertilizer once in early spring. Use fertilizer sparingly to avoid promoting leggy, sparse growth

Eggshell powder topdress:Crush dried, rinsed eggshells into a fine powder; sprinkle lightly over the soil surface in early spring to improve soil structure and add calcium without overfeeding
Pruning
  • Trim back stray, overgrown stems in early spring to maintain a neat, compact mat shape
  • Remove any dead, brown, or damaged foliage to improve air circulation
  • Avoid heavy shearing, as it can damage the dense, trailing growth habit and reduce foliage density
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Non-toxic to cats; no reported adverse effects from ingestion or contact

Humans: No known toxicity to humans; some juniper species are used in culinary and medicinal applications

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Garden Uses & Culture

Culture: Symbolizes endurance and resilience due to its ability to thrive in harsh, cold climates

Usage: Groundcover for erosion control on slopes, rock garden filler, or low-maintenance landscape borders