Siam tulip
Also known as
Thai tulip, Summer tulip, Patumma, Hidden ginger
Keep this plant’s care guide close at hand.
Get the appAbout Siam tulip
Curcuma alismatifolia, commonly called Siam tulip, is a rhizomatous perennial in the ginger family (Zingiberaceae) prized for its long-lasting, tulip-like bracts. Native to seasonally wet, open habitats of northeastern Thailand, Cambodia, and Laos, it forms upright clumps of lanceolate leaves from underground rhizomes in spring, followed by colorful summer inflorescences. The true flowers are small, nestled within tiers of pink to magenta bracts that persist for weeks, making it an excellent pot plant and cut flower. Plants typically reach 30–60 cm tall and enter dormancy as days shorten and soils dry, shedding foliage until the next warm, moist season. In cultivation it thrives in warm temperatures, bright filtered light, evenly moist yet sharply draining, humus-rich substrates, and moderate to high humidity. While closely related to culinary turmeric, this species is cultivated primarily for ornament. In temperate regions it is treated as a tender summer bulb outdoors or as a seasonal indoor accent, with rhizomes lifted or kept dry through winter.
Taxonomy
Properties & Requirements
How to care for Siam tulip
Water
During active growth, water deeply until excess drains, then allow the top 2–5 cm (1–2 in) to dry before rewatering. Even moisture supports bract longevity, but waterlogged media quickly rots rhizomes, so empty saucers promptly. Use room‑temperature, low‑salinity water. As foliage begins to yellow late season, progressively extend intervals. Once dormant, keep just barely dry—an occasional sip to prevent shriveling—or lift and store rhizomes dry. Resume regular watering when new shoots appear in spring.
Light
Provide bright, filtered light or gentle morning sun with afternoon shade. Indoors, place near an east window or a bright south window diffused with sheer curtains; outdoors, dappled shade beneath high canopies is ideal. Intense midday sun can scorch leaves and bleach bracts, while too little light elongates stems and reduces bloom. Aim for 6–8 hours of high ambient light daily (about 10,000–20,000 lux), rotating the plant weekly for even growth.
Nutrients
Feed from first emergence through early fall with a balanced, chloride-free fertilizer. Apply a half-strength 10-10-10 or 12-12-12 liquid every 2–3 weeks, or incorporate a slow-release granular at planting. Emphasize slightly higher potassium around budding and bloom to support bract color and stem strength. Avoid excessive nitrogen, which encourages foliage over flowers. Flush the potting mix monthly to limit salt buildup, and stop fertilizing as leaves yellow and the plant enters dormancy.
Temperature
Maintain warm conditions: 20–32°C (68–90°F) by day and preferably above 18°C (64°F) at night during growth. Avoid temperatures below 15°C (59°F), which stall growth and increase rot risk; the plant is strictly frost‑tender. In cool climates, grow as a summer patio plant and overwinter indoors. Store dormant, lifted rhizomes dry at 10–15°C (50–59°F) with ventilation. Prevent sudden temperature swings and cold drafts, which can deform bracts and reduce flowering.
