Small-calyx Cestrum (Cestrum microcalyx)

Small-calyx Cestrum

Cestrum microcalyx

Clusters of tiny white blooms release sweet night fragrance. Evergreen shrub; common name: Small-calyx Cestrum.

Full sun
1–2/week
Moderate
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Plant Needs

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Sunlight Full to partial sun; blooms most profusely in full sun; tolerates light shade in hot climates
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Watering Water deeply when the top 2–3 cm of soil is dry; avoid waterlogging to prevent root rot
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Temperature Thrives in warm temperate to tropical conditions; protect from frost below 10°C to prevent leaf damage
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Characteristics

  • Leaf: Simple ovate to lanceolate leaves; glossy dark green, 5–10 cm long
  • Flower: Tiny white tubular blooms in dense terminal clusters; fragrant at night
  • Stem: Woody branching stems with smooth light brown bark
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Care Guide

Watering

Keep soil consistently moist but not saturated

Fertilization

Feed monthly with balanced diluted liquid fertilizer. Discontinue fertilization in autumn to prepare the shrub for winter dormancy

Banana peel compost tea:Use fully composted banana peels; dilute 1:20 with water for root drenching to avoid attracting pests
Pruning
  • Deadhead spent flower clusters to promote continuous blooming through the growing season
  • Prune overgrown or leggy branches in late winter to maintain a compact, rounded shape
  • Remove damaged, diseased, or crossing stems to improve air circulation
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Toxic; contains alkaloids that may cause vomiting, diarrhea, lethargy, and tremors

Humans: Contains solanine-like alkaloids; ingestion causes mild gastrointestinal irritation; sap may irritate skin

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Garden Uses & Culture

Culture: N/A

Usage: Ornamental garden shrub valued for night-blooming fragrance