Eleocharis dulcis Chinese Water Chestnut

Eleocharis dulcis is the Chinese Water Chestnut — a marginal sedge grown across tropical and subtropical Asia for its crunchy, sweet-flavoured starchy corms, which are a staple ingredient in Asian cuisine. As a pond or paludarium plant, however, it is also highly ornamental: it produces dense clumps of bright-green, cylindrical, leafless stems 60–150 cm tall, creating an authentic tropical reed-marsh aesthetic wherever it is planted.

In an aquatic setting, C. dulcis thrives in shallow water or waterlogged substrate in full sun. It is a warm-season plant that requires temperatures above 20 °C for active growth and is frost-sensitive. In temperate climates it is grown as an annual or the corms are lifted and stored indoors over winter.

For aquarists building large tropical paludariums, Southeast Asian biotope open-top aquariums, or pond features, E. dulcis provides unmatched vertical reed-like structure with the added novelty of potentially harvesting edible corms in autumn.

Light: High; requires full sun or equivalent bright indoor lighting for strong, upright stem growth. CO2: Not required; emergent species accessing atmospheric CO2. Fertilisation: Rich aquatic soil or fertiliser tabs every 8 weeks during the growing season. Placement: Marginal zone at 5–20 cm water depth or in waterlogged substrate; needs open-top space for tall stems. Propagation: Plant corms in spring; side corms and new plantlets develop from the base of established clumps.