Sesbania Grandiflora (Agathi): Complete Growing & Uses Guide

Sesbania grandiflora, known as agathi, agati, vegetable hummingbird, or West Indian pea tree, is one of the most versatile multipurpose trees in the tropical world. Prized for its large edible flowers, high-protein foliage, rapid growth, nitrogen-fixing ability, and documented medicinal properties, this remarkable legume tree deserves far more attention from farmers, agroforesters, and nutrition-focused growers than it currently receives.

This comprehensive guide covers every aspect of Sesbania grandiflora — from taxonomy and botany through cultivation, nutrition, medicinal research, and commercial applications. Whether you are a farmer evaluating this species for your tropical operation, a researcher studying its phytochemistry, or a buyer sourcing agathi seeds for large-scale planting, this page provides the authoritative information you need.

Taxonomy & Botanical Description

Sesbania grandiflora is a fast-growing, soft-wooded tree that can reach 8 to 15 meters in height at maturity. The trunk is typically 25 to 30 cm in diameter with corky, light brown bark. Leaves are pinnately compound with 20 to 50 leaflets, each 2 to 4 cm long. The species is distinguished by its exceptionally large flowers — the largest in the Fabaceae family — measuring 7 to 10 cm in length. Flowers are either white (the most common form) or red/pink (var. rubra).

The tree produces flat, elongated pods 20 to 50 cm long, each containing 15 to 40 seeds. Seeds are cylindrical, light brown, and weigh approximately 35 to 45 grams per 1000 seeds — substantially larger than other Sesbania species.

Nutritional Profile

Sesbania grandiflora is nutritionally remarkable across its edible parts — leaves, flowers, and young pods all provide valuable macro- and micronutrients.

Leaves

Flowers

Young Pods

Medicinal Uses and Research

Sesbania grandiflora has a long history of use in traditional medicine systems, particularly Ayurveda, Siddha, and Southeast Asian folk medicine. Modern pharmacological research has begun to validate many of these traditional applications.

Anti-inflammatory Activity

Leaf and bark extracts of S. grandiflora have demonstrated significant anti-inflammatory activity in both in vitro and animal models. Ethanolic leaf extracts reduced carrageenan-induced paw edema in rats by 45 to 65 percent, comparable to standard anti-inflammatory drugs.

Kasture, V.S., Kasture, S.B., & Chopde, C.T. (2002). "Anti-inflammatory activity of Sesbania grandiflora leaves." Indian Journal of Pharmacology, 34(2), 121-123.

Antioxidant Properties

Methanolic extracts of S. grandiflora flowers and leaves showed strong DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, with IC50 values ranging from 42 to 58 micrograms per mL. The antioxidant capacity is attributed to high concentrations of phenolic compounds, flavonoids (including kaempferol and quercetin), and ascorbic acid.

Arun, A.B., Beena, K.R., Raviraja, N.S., & Sridhar, K.R. (2014). "Antioxidant potential of Sesbania grandiflora flowers." Asian Pacific Journal of Tropical Medicine, 7(Suppl 1), S474-S480.

Hepatoprotective Effects

Aqueous and ethanolic leaf extracts demonstrated significant hepatoprotective activity in rats with chemically induced liver damage. Treatment with S. grandiflora extracts (200-400 mg/kg body weight) reduced elevated serum liver enzymes (ALT, AST, ALP) and bilirubin levels toward normal ranges, with histopathological examination confirming reduced hepatocyte damage.

Ramesh, T., Mahesh, R., Sureka, C., & Begum, V.H. (2011). "Hepatoprotective effects of Sesbania grandiflora against carbon tetrachloride-induced hepatotoxicity in rats." BMC Complementary and Alternative Medicine, 11(1), 1-8.

Antimicrobial Activity

Leaf extracts exhibit broad-spectrum antimicrobial activity against both gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), as well as antifungal activity against Candida albicans and Aspergillus niger.

Anitha, R., Giridharan, P., & Srinivasan, M. (2010). "Antimicrobial activity of Sesbania grandiflora flower extract." Journal of Pharmacy Research, 3(9), 2155-2157.

Additional Pharmacological Activities

Published research also reports anxiolytic activity (anti-anxiety effects in animal models), anticonvulsant properties, antidiabetic potential (reduction of blood glucose in streptozotocin-induced diabetic rats), and antiulcer activity. Traditional Ayurvedic uses include treatment of nasal catarrh, headache, fever, and night blindness.

Cultivation Guide

Climate Requirements

• Hardiness zones: USDA 10-12 (minimum temperature above 1 degree Celsius)
• Optimal temperature: 25-35 degrees Celsius
• Rainfall: 1,000-4,000 mm annually; tolerates both wet and seasonally dry tropics
• Altitude: Sea level to 1,000 meters; best performance below 500 meters
• Frost tolerance: None — the tree dies at temperatures below -1 degree Celsius
• Light: Full sun; does not tolerate shade

Soil Requirements

• Soil pH: 5.5-8.0 (tolerates mildly acidic to mildly alkaline)
• Soil type: Grows on sandy, loamy, and clayey soils; prefers well-drained but tolerates brief waterlogging
• Salinity: Moderate tolerance — survives in soils with EC up to 6 dS/m
• Fertility: Grows on poor soils due to nitrogen fixation; benefits from phosphorus application at planting

Planting and Spacing

Water and Irrigation

Sesbania grandiflora grows well under rainfed conditions receiving 1,000+ mm annual rainfall. Under irrigation, it produces maximum biomass and flowers with consistent moisture. Young trees (first 3 months) require regular watering until roots are established. Mature trees tolerate brief dry spells of 2 to 4 weeks but drop leaves and cease flowering during extended drought.

Seed Treatment

Sesbania grandiflora seeds have moderate physical dormancy due to a hard seed coat. Pre-treatment improves germination rate from 60-70% (untreated) to 85-95% (treated). Recommended methods include hot water scarification (soak seeds in 80 degree Celsius water for 3 minutes, then cool water for 12 hours) or mechanical scarification (light abrasion with sandpaper). Inoculation with Rhizobium species specific to Sesbania enhances nitrogen fixation.

Fodder Use: High-Protein Tropical Tree Fodder

Sesbania grandiflora leaves are among the most nutritious tree fodders available in the tropics, with crude protein content of 27 to 30 percent on a dry matter basis. This places them on par with alfalfa — but unlike alfalfa, Sesbania grandiflora thrives in hot, humid lowland tropics where alfalfa fails.

Unlike leucaena, which contains the toxic amino acid mimosine (limiting intake to 30% of the diet), Sesbania grandiflora can be fed freely to ruminants without toxicity concerns. This makes it a safer, more versatile protein supplement for smallholder dairy and goat operations across the tropics.

Under intensive management with coppicing every 8 to 12 weeks, a well-managed Sesbania grandiflora stand can produce 15 to 25 tonnes of fresh foliage per hectare per year — equivalent to 4 to 7 tonnes of dry matter with 1.1 to 2.1 tonnes of crude protein per hectare.

Edible Uses in Southeast Asian Cuisine

Sesbania grandiflora flowers are a celebrated ingredient across Southeast Asian culinary traditions. The tree's cultural and gastronomic significance is deeply embedded in regional food systems.

Thailand (Dok Khae)

White flowers are blanched and served as a side vegetable with nam prik (chili paste). They are also used in kaeng som (sour curry) and omelettes. The young leaves are eaten fresh in salads. Dok khae is a common sight in Thai wet markets throughout the southern and central regions.

Philippines (Katuray)

Flowers are used in tinola (chicken soup), sinigang (sour soup), and adobo preparations. They are also battered and fried as fritters — a popular street food. Young pods are cooked as a vegetable similar to green beans.

Indonesia (Turi)

Flowers are used in pecel (peanut sauce salad), urap (coconut vegetable mix), and various sayur (soup) preparations. In Java, turi flowers are a traditional component of the sacred food offering during cultural ceremonies.

India (Agathi)

In South India, particularly Tamil Nadu and Kerala, agathi leaves and flowers are consumed as thoran (stir-fry with coconut), used in dals, and made into chutneys. The leaves are considered a medicinal food that "cools" the body and is eaten during periods of illness or recovery.

The flavor of Sesbania grandiflora flowers is described as mild, slightly sweet, with a mushroom-like texture that absorbs surrounding flavors. Red-flowered varieties tend to have a slightly more bitter taste than white-flowered forms, though both are widely consumed.

Timber, Firewood, and Pulpwood

While not a premium timber species, Sesbania grandiflora provides several wood-product benefits in tropical agroforestry systems:

• Firewood: Fast-growing fuelwood with a calorific value of approximately 4,600 kcal/kg — acceptable for cooking fuel in rural areas, though not as dense as slower-growing hardwoods
• Pulpwood: Increasingly used as a short-rotation pulpwood species in India and Southeast Asia. The wood has excellent pulping characteristics with fiber length of 1.0-1.4 mm, low lignin (18-20%), and low chemical requirements for processing
• Light construction: The soft, lightweight wood is used for temporary structures, trellises, and crop support stakes
• Biomass production: Yields of 20-40 tonnes of fresh biomass per hectare per year make it one of the most productive tropical biomass species for bioenergy

Ornamental and Landscape Value

Sesbania grandiflora is an attractive ornamental tree for tropical gardens and landscapes. Its distinctive features include rapid establishment (providing shade within 6-12 months), large, showy flowers that bloom abundantly and attract pollinators (particularly sunbirds and bees), a graceful canopy form with fine-textured foliage, and the red-flowered variety (var. rubra) which is especially ornamental with its deep crimson blooms. The tree is suitable for parks, gardens, roadsides, and institutional landscapes in tropical and frost-free subtropical regions.

Nitrogen Fixation and Soil Improvement

Like all Sesbania species, S. grandiflora fixes atmospheric nitrogen through symbiosis with Rhizobium bacteria in root nodules. A mature tree can fix 50 to 80 kg of nitrogen per hectare annually through leaf fall, root turnover, and pruning residues returned to the soil. When grown as an alley crop between rows of annual crops, its prunings serve as a nutrient-rich mulch and green manure that improves soil organic carbon, nitrogen availability, and microbial activity.