Whether called curcumin, turmeric or the Indian saffron plant, few people outside tropical southern Asia would have any idea what it looks like or how it grows. This herbaceous plant develops fleshy orange tubers, becoming the spice turmeric when dried and pulverized. It is an important component of curry powder and tastes good when eaten in its fresh and juicy state.
Centuries of trade of the spice turmeric causes the precise origin or nativity of the Indian saffron (Curcuma longa) plant to remain ambiguous. Botanists agree that a likely native range for the plant centers around tropical south-central Asia or the nearby peninsula of southeastern Asia.
Growing about 2 to 4 feet tall, Indian saffron is a tropical herbaceous perennial that goes dormant during the winter dry season. Its roots form swollen tubers with an oblong and branching structure and have a core colored vividly orange when cut open. In the warmth of spring when rains return, the leaves and stems emerge from the ground, become 2-foot-long tapered ovals of medium to deep green. Crushing the leaves releases a spicy scent. In summer's warmth, humidity and rains, a short flower stalk emerges from the soil and bears a cluster of creamy white bracts that collectively resemble a tiny pine cone or pineapple top. Within the bracts arise the real flowers, which are small and bright golden yellow. In autumn as soil temperatures cool and summer rainfall wanes, the foliage naturally degrades. By the dry winter season, the plant disappears, remaining alive but dormant underground in the firm, juicy tubers.
Plant rhizomes of Indian saffron in sandy soil rich in organic matter. Ideally, the soil has an acidic pH (6.0 to 6.8). Naturally growing in the shifting shade and sunlight under rain forest trees, this plant needs bright indirect light and occasional exposure to direct sunlight across the day, especially at sunrise or sunset when the sun rays are not intense. Do not expose the foliage to more than four hours of direct sun when actively growing. Abundant watering occurs from spring to early fall as long as soil temperatures remain above 75 degrees Fahrenheit and air temperatures reach over 80 to 90 degrees. When the foliage wanes in autumn, reduce watering and stop any irrigation from autumn to spring to ensure that the dormant tubers do not rot in overly moist soil. Increase watering again in spring after the first signs of new leaves emerge from the soil surface. Plant Indian saffron outdoors in frost-free climates, those in USDA Hardiness Zones 10 and warmer.
Curcumin, a yellow pigment, is but one component of turmeric, the spice derived from the dried and pulverized rhizome of the Indian saffron plant. In traditional Asian medicine, turmeric treats gastrointestinal upset, arthritic pain and bouts of decreased physical energy. Anti-inflammatory, antioxidant and anti-cancer properties of turmeric and its component curcumin may assist in managing heartburn, high cholesterol and scabies.
The underground tubers taste of a pungent combination of orange citrus and ginger and flavor culinary dishes, especially those with origins in southern Asian cultures. The pigment in the roots also act as a fabric dye. In tropical gardens, the seasonal foliage and flowers of Indian saffron decorate the mixed garden border or patio containers. In cold climates, the roots of Indian saffron may be grown in pots as a house plant and moved outdoors when there is no danger of frost. The history of this plant dates to the ancient spice trade, and the experience of touching and seeing the live plant that supplies turmeric makes it a conversation piece in your garden.