Rocky Mountain Juniper (Juniperus scopulorum) Bonsai Care Timeline

Rocky Mountain Juniper (Juniperus scopulorum) is an evergreen conifer native to western North America, from British Columbia south to New Mexico and east to the Dakotas. It grows on dry, rocky slopes, canyons, and high plains at 3,000–9,000 feet, often in pinyon-juniper woodlands with full sun and poor soils, reaching 30–50 feet tall with a conical to irregular form, scale-like foliage, and reddish-brown bark that shreds in strips.

It is drought- and cold-tolerant, with blue-green foliage and small blue berries on female trees. In bonsai, Rocky Mountain Juniper is one of the best North American junipers for its fine scale foliage, prolific deadwood, and rugged character, suiting windswept, literati, or upright styles. It is popular in the USA for Rocky Mountain yamadori. In USDA Zone 7 it is hardy outdoors with full sun and sharp drainage.

Evergreen conifer; outdoor in Zone 7.

Spring (Mid-March – Mid-May)

Goal: Promote dense new growth.

  • Light: Full sun.
  • Watering: Every 2–4 days when topsoil dries.
  • Fertilizing: Balanced organic every 3–4 weeks from mid-April.
  • Pruning: Pinch new tips for density.
  • Wiring: Late spring.
  • Repotting: Every 3–5 years early spring; high-drainage mix.
  • Pests/Diseases: Spider mites, bagworms; neem preventive.
  • Notes: Excellent drainage essential.

Summer (Mid-May – August)

Goal: Maintain compact foliage.

  • Light: Full sun.
  • Watering: Daily in heat.
  • Fertilizing: Balanced; reduce in extreme heat.
  • Pruning: Regular pinching.
  • Wiring: Monthly checks.
  • Repotting: Avoid.
  • Pests/Diseases: Mites; hose foliage.
  • Notes: Drought-tolerant once established.

Fall (September – Mid-November)

Goal: Refine structure.

  • Light: Full sun.
  • Watering: Every 3–5 days.
  • Fertilizing: Low-nitrogen September.
  • Pruning: Light thinning.
  • Wiring: Good for styling.
  • Repotting: Avoid.
  • Pests/Diseases: Low.
  • Notes: Blue berries on females.

Winter (Mid-November – Early March)

Goal: Dormancy.

  • Light: Sunny shelter.
  • Watering: Every 7–14 days.
  • Fertilizing: None.
  • Pruning: Minimal.
  • Wiring: Avoid.
  • Protection: Mulch pot; hardy.
  • Notes: Very cold-tolerant.

Zone 7 Tips: Full sun and sharp drainage; excellent native juniper for deadwood and rugged style.