Hino Crimson Azalea (Rhododendron obtusum)

Hino Crimson Azalea

Rhododendron obtusum

A dense, evergreen shrub celebrated for its brilliant, profuse crimson-red spring blooms. Other names: Kurume Azalea.

Prefers dappled shade or morning sun with afternoon shade to prevent leaf scorch.
1/week
Moderate
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Plant Needs

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Sunlight Prefers dappled shade or morning sun with afternoon shade to prevent leaf scorch.
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Watering Requires consistently moist, well-drained soil; intolerant of drought or standing water.
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Temperature Hardy in USDA zones 6-9; benefits from protection against harsh winter winds.
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Characteristics

  • Leaves: Small, glossy, dark green, elliptic to obovate, turning bronze or purplish in winter;
  • Flowers: Funnel-shaped, vibrant crimson-red, blooming profusely in clusters that completely cover the foliage;
  • Habit: Dense, rounded, spreading evergreen shrub with a shallow, fibrous root system;
  • Bark: Thin, grayish-brown, becoming slightly scaly with age.
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Care Guide

Watering

Keep soil consistently moist, watering deeply when the top inch of soil feels dry.

Fertilization

Apply an acid-loving plant fertilizer immediately after blooming finishes.. Avoid over-fertilizing, as shallow roots are easily burned by excess salts.

Coffee Grounds Amendment:Sprinkle used, cooled coffee grounds lightly around the base to help maintain soil acidity and add organic matter. Avoid creating thick layers that might block water penetration.
Pruning
  • Prune immediately after spring flowering to shape the shrub and control size;
  • Avoid late summer or fall pruning, as this will remove next year's flower buds;
  • Remove dead, damaged, or crossing branches to improve air circulation and plant health.
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: Highly toxic per ASPCA; ingestion of even a few leaves can cause severe poisoning.

Humans: Highly toxic if ingested; contains grayanotoxins which disrupt sodium channels in cell membranes.

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Garden Uses & Culture

Culture: A staple in Southern US and European woodland gardens, azaleas symbolize vibrant spring awakening, temperance, and passion in Western horticultural traditions.

Usage: Excellent for foundation plantings, shrub borders, mass planting, woodland garden edges, and container gardening.