Christmas Senna (Senna bicapsularis)

Christmas Senna

Senna bicapsularis

Golden winter blooms light up cool gardens, a cheerful splash of color. Deciduous flowering shrub; common names: Christmas Senna, Winter Cassia.

Full sun
1–2/week
Moderate
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Plant Needs

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Sunlight Full sun to partial shade; produces the most blooms in full sun, tolerates reflected heat in arid regions
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Watering Water deeply when the top 5 cm of soil is dry; avoid overwatering to prevent root rot and fungal issues
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Temperature Hardy to 10°C; protect from frost damage in cool climates; thrives in warm temperate to tropical conditions
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Characteristics

  • Leaf: Pinnately compound, 10–15 cm long; oval glossy green leaflets that fold at night
  • Flower: Dense clusters of bright yellow pea-like blooms, 2–3 cm diameter, lightly fragrant
  • Stem: Woody branching stems with light brown bark; young growth is green and finely hairy
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Care Guide

Watering

Keep soil consistently moist during active growth periods

Fertilization

Apply balanced slow-release fertilizer once at the start of growth. Avoid high-nitrogen fertilizers to prevent excessive foliage growth at the expense of blooms

Composted banana peel tea:Soak fully composted banana peels in water for 24 hours; dilute 1:20 for root drenching; discard solid material to avoid pest infestations and odor
Pruning
  • Prune lightly immediately after flowering to maintain a rounded shape and encourage new growth
  • Remove dead, diseased, or crossing branches in early spring to improve airflow
  • Thin overcrowded stems to increase light penetration and promote more abundant blooms
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA confirmed toxic; contains anthraquinones that irritate the digestive tract

Humans: Ingestion of large amounts may cause gastrointestinal upset including nausea and diarrhea

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Garden Uses & Culture

Culture: Associated with winter seasonal cheer; planted for bright color during cool, low-bloom months

Usage: Ornamental garden shrub; attracts pollinators including bees and butterflies