Tacca leontopetaloides aka Polynesian Arrowroot

Tacca leontopetaloides is a challenging plant best suited for experienced growers. It requires consistent warmth (never below 15°C/59°F), high humidity, filtered light, and reliably moist soil during the growing season. The plant also undergoes seasonal dormancy requiring adjusted watering. Success is most likely in USDA zones 8-11 outdoors or in a warm greenhouse with careful attention to humidity levels.

During the active growing season (spring through autumn), keep the soil consistently moist but never waterlogged. Water when the top inch of soil begins to dry. The plant is native to tropical regions with regular rainfall and does not tolerate drought. During dormancy (typically winter), reduce watering significantly—allow the soil to dry more between waterings while the tuber rests underground.

Tacca leontopetaloides thrives in fertile, humus-rich soil with excellent drainage. A mix of well-draining potting soil with added organic matter works well. The plant tolerates sandy, loamy, or clay-based soils as long as they don't become waterlogged. Slightly acidic to neutral pH (5.5-7.0) is ideal, mimicking its native tropical forest floor conditions.

This tropical species requires high humidity levels, ideally 60-80% or higher. In drier climates, regular misting, a pebble tray with water, or a room humidifier can help maintain adequate moisture around the foliage. Grouping with other tropical plants also creates a more humid microclimate. Low humidity leads to brown leaf edges and poor growth.

Apply a balanced fertilizer (10-10-10 or similar) every 4-6 weeks during the active growing season to support the plant's rapid growth. Reduce or stop fertilizing as the plant enters dormancy in late autumn. Organic fertilizers or slow-release formulations work well. Avoid over-fertilizing, which can damage the tubers.

Tacca leontopetaloides can be propagated by tuber division or from seed. Divide tubers during the dormancy period by carefully separating smaller rhizomes that form around the main tuber, ensuring each division has at least one growth point. Seeds should be sown fresh in warm, moist conditions—germination can be slow and erratic. Plants from seed may take 3 years to flower and develop mature tubers.

Tacca leontopetaloides is a fast-growing plant reaching approximately 1 meter (3 feet) in both height and spread at maturity. The impressive leaves can span 30-70 cm long and up to 120 cm wide, carried on petioles up to 150 cm tall. Flower stalks reach similar heights. The underground tubers typically grow 10-15 cm in diameter, though can reach 30 cm in ideal conditions. Growth completes in 8-12 months before seasonal dormancy.

The flowers of Tacca leontopetaloides are spectacularly unusual, giving the plant its common name 'Bat Flower.' The inflorescence appears on stalks up to 1 meter tall, featuring clusters of small yellow-green to purple flowers surrounded by large, dramatic bracts. Most distinctive are the long, whisker-like bracteoles that can extend up to 25 cm (10 inches), drooping like bat whiskers. Blooming occurs during the summer growing season.

Tacca leontopetaloides has a pronounced seasonal cycle. During winter (typically December in the Southern Hemisphere), the plant enters dormancy—leaves yellow and die back to ground level. Reduce watering significantly during this period but don't let tubers dry completely. New growth emerges in spring (around March), signaling time to resume regular watering and feeding. During the active growing season, maintain consistent moisture, warmth, and humidity.

Tacca leontopetaloides can be grown outdoors year-round in USDA zones 8-11 where frost is rare or absent. It thrives in tropical and subtropical gardens with partial shade, consistent moisture, and protection from harsh afternoon sun. In cooler climates, grow in containers that can be moved indoors or to a greenhouse when temperatures drop below 15°C (59°F). The plant naturalizes well in suitable coastal and tropical locations.

As a tropical species, Tacca leontopetaloides requires consistent warmth. Ideal growing temperatures range from 20-30°C (68-86°F). The plant cannot tolerate frost and suffers below 15°C (59°F). During dormancy, slightly cooler temperatures (around 15-18°C) are acceptable, but the tubers should never freeze. Consistent warmth is essential for healthy growth and flowering.

Repot Tacca leontopetaloides every 2-3 years or when the plant outgrows its container. The best time is during the dormancy period or just as new growth begins in early spring. Choose a pot slightly larger than the current one with excellent drainage. Handle the tubers carefully when repotting. Use fresh, humus-rich potting mix and position the tuber at the same depth as before.

Tacca leontopetaloides requires minimal pruning. Remove dead or yellowing leaves as they appear to maintain plant health and appearance. When the plant enters dormancy and foliage dies back naturally, allow leaves to yellow completely before removing them—this helps nutrients return to the tuber. Do not cut back foliage prematurely as this weakens the tuber for the next growing season.

Tacca leontopetaloides is relatively trouble-free when grown in appropriate conditions. Missouri Botanical Garden notes 'no significant pest or disease problems.' Potential issues include root rot from overwatering or poor drainage, particularly during dormancy. Spider mites and mealybugs may occasionally appear in dry conditions—maintain humidity to prevent these. Good air circulation helps prevent fungal issues.

Yes, the tubers of Tacca leontopetaloides are edible after proper processing. The starch extracted from tubers, known as 'Tahiti Arrowroot' or 'Fiji Arrowroot,' was historically a staple food in Pacific Island cultures. However, raw tubers contain taccalin, a bitter toxic compound that must be removed through thorough washing, grating, soaking, and drying. Never consume raw tubers. The processed starch is used in breads, soups, and traditional dishes like poi.

Tacca leontopetaloides has several traditional medicinal applications in Pacific Island and tropical Asian cultures. The root juice is traditionally used as an eye rinse for injured eyes. The starch is used to treat diarrhea and dysentery. Topically, preparations are applied to sores, burns, and insect stings (particularly bee and wasp stings). Roasted stem sap serves as eardrops for earache. These are folk remedies; consult healthcare providers for medical conditions.

Beyond food and medicine, Tacca leontopetaloides has practical craft applications. The fibrous leaf stalks and flower scapes provide excellent material for weaving hats, bonnets, and brooms. The fresh extracted starch serves as clothing starch and an adhesive. Historically, the starch was important in tapa cloth production, used to assemble and stiffen the bark cloth layers. PFAF rates these other uses 3 out of 5.

Polynesian Arrowroot’s native range is Widely spread in tropical areas, either as a native plant or naturalized, from Africa, through Asia to Australia and the Pacific..

To ensure optimal growth, the Polynesian Arrowroot prefers bright diffused light for 6-8 hours each day. Insufficient light can result in slow growth and leaf drop, so it's important to find a well-lit location for this plant. Place it near a window, within a distance of 1 meter (3 feet), to enhance its potential for thriving.

Ploi's records do not contain confirmed information on the toxicity of this particular plant. In the event of accidental ingestion of plant material with questionable toxicity by you, a family member, or a pet, it is always a good idea to consult a healthcare professional.