How to Grow & Care for Dok Khae (Hummingbird Tree) Organically in Hua Hin

 Learn to grow and care for Dok Khae in Hua Hin's tropical climate. This guide covers planting, watering, fertilizing, and organic pest control for the edible Hummingbird Tree.

Hua Hin Tropical Garden Organic Care & Propagation Guide for Agasta (Hummingbird Tree / ดอกแค / Sesbania grandiflora)

Common Names:

• Hummingbird Tree, Agasta, Corkwood Tree, Scarlet Wisteria
• Thai: ดอกแค (Dok Khae), แคบ้าน (Khae Ban)

Overview:
Sesbania grandiflora is a fast-growing, nitrogen-fixing tropical tree known for its edible flowers, leaves, and pods. It thrives in warm climates like Hua Hin and is valued for its ornamental beauty, medicinal properties, and use in organic farming.

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Organic Care Guide

1. Climate & Soil Requirements

• Climate: Prefers hot, tropical climates (25–35°C). Tolerates drought but grows best with consistent moisture.
• Soil: Grows in well-draining, loamy or sandy soil (pH 6.0–7.5). Tolerates poor soils but benefits from organic matter.
• Sunlight: Full sun (6–8 hours daily).

2. Planting & Spacing

• From Seeds: Soak seeds in water for 24 hours before planting. Sow 1–2 cm deep in seed trays or directly in the ground.
• From Cuttings: Take semi-hardwood cuttings (30–50 cm long) and plant in moist soil.
• Spacing: 3–5 m apart (for tree form) or 1–2 m apart (for hedge/vegetable use).

3. Watering

• Young Plants: Water daily for the first 2–3 weeks.
• Mature Trees: Deep water 2–3 times per week (drought-tolerant but grows faster with moisture).
• Avoid waterlogging (can cause root rot).

4. Organic Fertilization

• Compost/Manure: Apply well-rotted compost or cow manure around the base every 2–3 months.
• Liquid Fertilizer: Use compost tea or fish emulsion monthly for faster growth.
• Mulching: Apply organic mulch (straw, leaves, grass clippings) to retain moisture and suppress weeds.

5. Pruning & Maintenance

• Prune regularly to encourage bushier growth and more flowers.
• Remove dead/diseased branches to prevent pest issues.
• Coppicing: Can be cut back hard (to 1 m) for regrowth as a vegetable crop.

6. Pest & Disease Management (Organic Solutions)

• Common Pests: Aphids, caterpillars, leaf miners.
  • Neem oil spray (weekly if infestations occur).
  • Garlic/chili spray for deterring insects.
• Diseases: Root rot (from overwatering), fungal leaf spots.
  • Improve drainage and avoid overhead watering.
  • Spray with baking soda solution (1 tsp baking soda + 1L water) for fungal issues.

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Propagation Methods

1. Seed Propagation (Most Common)

• Step 1: Collect mature pods (brown and dry).
• Step 2: Soak seeds in warm water for 24 hours to soften the hard coat.
• Step 3: Sow seeds 1–2 cm deep in seed trays or directly in soil.
• Step 4: Germinates in 5–14 days. Transplant when seedlings are 15–20 cm tall.

2. Stem Cuttings (Less Common but Effective)

• Step 1: Take 30–50 cm long semi-hardwood cuttings from healthy branches.
• Step 2: Remove lower leaves and dip the cut end in honey or rooting hormone.
• Step 3: Plant in moist, sandy soil and keep shaded until roots develop (~4–6 weeks).

3. Air Layering (For Faster Flowering)

• Step 1: Select a healthy branch and make a 2 cm ring cut to remove bark.
• Step 2: Apply rooting hormone and wrap with moist sphagnum moss + plastic.
• Step 3: Roots form in 4–8 weeks. Cut and plant the new sapling.

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Harvesting & Uses

• Flowers: Harvest young, unopened buds for cooking (used in Thai soups like แกงแค - Gaeng Khae).
• Leaves & Pods: Edible when young (rich in protein, vitamins A & C).
• Medicinal Uses: Flowers used in traditional medicine for anti-inflammatory, antioxidant, and cold relief.

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Conclusion

Sesbania grandiflora is an excellent fast-growing, nitrogen-fixing, multi-purpose tree for Hua Hin’s tropical climate. With minimal care, it provides edible flowers, shade, and soil improvement. Propagate via seeds or cuttings for best results.