Source: Wikimedia Commons
Water hyacinth
BeginnerPontederia crassipes
A South American floating plant buoyed by swollen, bladder-like petioles, bearing pale violet flowers in summer. Extremely prolific and designated a Priority Control Alien Species in Japan, so it must never escape into outdoor waters.
About
Water hyacinth (Pontederia crassipes, formerly Eichhornia crassipes) is a free-floating perennial of the Pontederiaceae native to South America. It is now naturalised throughout the tropics and subtropics and is a serious aquatic weed in many countries. Its swollen petioles act as floats, and blue-black fibrous roots hang in the water; in summer a flower spike bears many pale violet flowers. It produces daughter plants on runners so fast that mats can double in one to two weeks, and its seeds stay viable for many years. It reached Japan as an ornamental in the Meiji era (possibly earlier) and is naturalised in Honshu, Shikoku, Kyushu and the Nansei Islands. The Ministry of the Environment's 2nd edition list (September 2026) designates it a Priority Control Alien Species. It is not a Specified Invasive Alien Species, so selling and growing it are legal, but it must not be brought into natural waters and must be managed so it cannot escape. It likes strong light, warm water and high nutrients and suits outdoor containers and biotopes; indoors in weak light it gradually declines. It is widely sold in summer, including at home centres.
Source: Wikipedia (CC BY-SA 4.0)
Size of the Water hyacinth
The Water hyacinth grows to Usually a few tens of cm; up to about 1.5 m when rooted in mud.
Temperature & humidity for the Water hyacinth
The ideal temperature for the Water hyacinth is 25〜30℃.
Basic Info
Origin
South America (e.g. Brazil); naturalised throughout the tropics and subtropics
Lifespan
Perennial; easily killed by cold
Size
Usually a few tens of cm; up to about 1.5 m when rooted in mud
Temperature
25〜30℃
Watering & Fertilizer
Prefers nutrient-rich water; leaves pale when starved
Growing Tips
Lighting
Needs full sun; in weak light such as indoors it gradually declines and dies.
CO2 & Fertilizer
No CO2 needed. It thrives in nutrient-rich water; poor growth and pale leaves usually mean starvation or cold.
Water Temperature & Quality
Optimum 25–30°C. Cold-sensitive; most plants die in winter, so keep it warm and bright indoors if overwintering.
Substrate & Attachment
Grown floating on the surface in outdoor containers, biotopes or large open-topped tanks.
Trimming & Propagation
Produces daughter plants on runners; remove surplus plants regularly.
Cautions
Listed as a Priority Control Alien Species. Never dump it in rivers, ponds or ditches, and prevent overflow from containers in heavy rain. Dry unwanted plants before binning them.
Water hyacinth FAQ
QWhat is the growing difficulty level for Water hyacinth?
Beginner. A variety suitable for beginners. No special equipment or experience is required—you can grow it without problems by setting up a basic cultivation environment.
QWhat is the ideal temperature for Water hyacinth?
The ideal temperature for Water hyacinth is 25〜30℃. Avoid sudden temperature changes and maintain a stable environment.
QHow large does Water hyacinth get?
The mature size of Water hyacinth is Usually a few tens of cm; up to about 1.5 m when rooted in mud. This may vary slightly depending on cultivation environment and individual differences.
QHow should I water and fertilize Water hyacinth?
Water hyacinth: watering & fertilizer — Prefers nutrient-rich water; leaves pale when starved. Aim for appropriate frequency and amount.
QWhat is the typical price for Water hyacinth?
The price of Water hyacinth varies significantly by variety, characteristics, size, and lineage. Please check GrowerDirect's price guide for the latest market information.
Last updated: September 23, 2026
References & Sources
Edited & verified by: GrowerDirect Editorial Team
The classifications, regulations, and growing data on this page are created and verified based on the primary information database below.
Taxonomy & Authority
Regulations & Conservation Status
Not listed in CITES (no match in Species+). Designated a Priority Control Alien Species in the Ministry of the Environment's list of alien species that may damage ecosystems (2nd ed., September 2026). It is not a Specified Invasive Alien Species, so it can be sold and grown, but it must not be introduced to natural waters and must be managed to prevent escape. Never dump it in rivers, ponds or ditches.
Sources: Species+ (CITES listing check) / Ministry of the Environment: List of Alien Species that may Damage Ecosystems / Ministry of the Environment: alien species list, plants (2nd ed.)
Regulations may change. Always verify the latest information with the relevant authorities.
Related Species
Find listings for this species
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