Eichhornia crassipes

IMPORTANT: in order to preserve our natural ecosystems and in accordance with European Regulation No. 1143/2014 on the prevention and management of the introduction and spread of invasive alien species, we have removed this plant from our catalogue. Therefore, it is no longer available for sale.

Eichhornia crassipes, also known as water hyacinth, is a non-hardy aquatic perennial with glossy green rounded leaves arranged in rosettes. It blooms in summer with pretty pale-violet flowers marked with light blue and gold. The flowers are borne on upright terminal spikes. It floats on water without the need to root. It should be used in closed ponds only.

Eichhornia crassipes belongs to the Pontederiaceae family. It is native to South America, specifically the Amazon basin. It does not tolerate frost. The plant has a rosette habit, reaching a height of 45cm (18in) when flowering with a minimum spread of 45cm (18in). A colony of interconnected plants can quickly cover a large water surface. Water hyacinth, which is not related to the true hyacinth family, is an aquatic perennial with thick, waxy, rounded and glossy leaves held above the water surface on stems. The leaves are roughly ovate to circular, 10 to 20cm (4 to 8in) in diameter, with undulate edges. The leaf veins are dense, numerous, almond-shaped, and longitudinal. Water hyacinth grows from a bulbous and spongy rootstock rhizome measuring up to 6cm (2in) in diameter and 30cm (12in) in length. The roots are dark purple and feathery, measuring up to 300cm (118in) and constituting over 50% of the standing crop biomass of a water hyacinth population. The growth of this plant is one of the - if not the - fastest in the plant kingdom: water hyacinths can grow from 2 to 5m (7 to 16ft) per day in some Southeast Asian sites.

Set water hyacinth on calm water at 13 to 16°C (55.4 to 60.8°F). Overwinter under shelter at a minimum of 15°C (59°F), in full light, in tanks filled with water and sand. Cultivating in a garden pond requires plenty of light, nutrient-rich medium, slightly acidic freshwater, and a humidity-saturated atmosphere. The annual temperatures range from 21 to 28°C (69.8 to 82.4°F) (average of 5 cases = 24.9°C (76.82°F)), and its pH tolerance is estimated at 5.0 to 7.5. Water hyacinth does not tolerate water temperatures above 34°C (93.2°F). The leaves are killed by freezing temperatures and saltwater. In brackish water, the leaves show chlorosis and eventually die. It should be reserved for large ponds, particularly garden ponds containing burrowing fish. The interwoven roots seen from below can have a decorative effect and provide refuge for fry. Lightly submerged roots are suitable for spawning and fry development as well as plankton cultivation.

The epithet "crassipes" of water hyacinth indicates "thick-footed" in reference to the swollen base of the petiole. It is one of the most dynamic known plants, reproducing mainly vegetatively through stolons, which eventually form daughter plants. Vegetative multiplication is very active under favourable conditions. Each plant can produce thousands of seeds every year, and these seeds can remain viable for over 28 years (recorded). Common water hyacinths (Eichhornia crassipes) are vigorous producers known to double their population in two weeks!