Water Hyacinth

Susan Patterson
water hyacinth

Water hyacinths (Eichhornia) are free-floating, aquatic flowering plants with a definite preference for warm weather. They belong to the genus Eichhornia. These natives of South American tropical waters enjoy a worldwide distribution now and are very popular in home water features.

Plant Description

The plants float on the water, with only the hairy fibrous root system staying underwater. However, if the roots touch the soil, as it usually happens at the edge of the ponds, they dig into the wet mud, resulting in vigorous growth. The leaf stalks are bulbous with air spaces inside, keeping the leaves and flower stalks afloat. Stolons sent out from the highly reduced stem bear baby plants, which stay connected to the mother, forming colonies. They grow rapidly and double in size in one to two weeks.

Zone Compatibility

Being tropical plants, they are naturalized in Florida and parts of Texas and California. They do well in USDA zones 9 - 11, but can be successfully grown in tubs and over wintered in greenhouses in other zones. In the northern states, they are treated as annuals as they die out below 200 to 250 F.

Procuring the Plants

Many garden centers have water hyacinths in stock. Buy only a few plants at a time as they reproduce rapidly. Most people will gladly give away excess plants. A small offshoot is enough to start growth. They can be propagated from seeds too, but they should be planted before they go into dormancy. Water hyacinths come in seven different species, but the flower color remains light pink to lavender, although it can sometimes be white. A few popular ones include:

  • Eichhornia crassipes is the common water hyacinth.
  • Eichhornia azurea, or Peacock hyacinth, likes to be potted and has fragrant flowers.
  • Eichhornia paniculata, or Brazilian water hyacinth, is smaller and less invasive.

They are prohibited in Florida and Texas, and discouraged in California. Check whether growing from existing wild stock is permitted.

Cultural Requirements

water hyacinths

Eichhornias can be grown in pots, tubs, and ponds of any size. Just put them in the water in spring after removing damaged leaves and some of the darker colored, older roots. They do well with guppies, minnows, and turtles.

  • Warmth is the main requirement for growth; they flower best in summer months.
  • A sunny location will ensure a continuous supply of flowers. In shady areas plants become taller and darker with few flowers.
  • Nutritional supplementation with a potash fertilizer may be necessary, especially in small ponds with limited animal life.
  • Neutral or near neutral water is preferred.
  • Though free-floating, adding a little soil to the container is good for them.

Maintenance and Care

Yellow leaves indicate nutrient deficiency. Fertilizers that are not harmful to aquatic animals can be added directly into the pond. Standing the plants in Miracle-Gro for a day or two and returning them to the pond will also help.

In areas with cold winters, the plants will wither and turn to slush. Removing the plants completely in late fall will help avoid a mess. Save a few for the next growing season by keeping them in a tub in a warm, bright place indoors.

Uses

Besides being esthetically appealing, the plants have a few uses.

  • Cleaning water
  • Preventing algal blooms and purifying water contaminated with heavy metals and other toxic chemicals
  • Providing bio waste for compost - Eichhornia mats, raked off the water and allowed to dry for a day or two, can be added to compost heaps with great results.

Food Source

Rich in proteins, water hyacinths make good cattle feed. The leaves and flowers are considered good for human consumption too, but only after cooking as they contain high amounts of calcium oxalate crystals, which cause itching. Only plants growing in clean water, uncontaminated by chemical effluents, should be used.

Aquatic Life Protection

The hairy roots offer a safe zone to fish eggs and tiny fries. They are good recyclers of nitrogenous waste generated by fish and other aquatic animals. Some fish nibble the roots.

Common Problems

Eichhornias provide an ideal home for mosquitoes to breed. Solutions include keeping the water agitated with a water pump, growing larvae-eating fish such as guppy and gambusia, and using mosquito dunks.

Vigorous growth makes the plant a menace in ponds and lakes in warm areas. They destroy oxygenating plants by reducing light and nutrition, killing animals that depend on these plants for food and oxygen. However, in a garden setting, just pull out excess plants and add them to the compost heap. Never discard them in or near a water source.

Enjoy Water Hyacinth Beauty Cautiously

Having a few of these hyacinths will brighten up your pond or water feature. Don't go overboard with them and provide proper maintenance to keep everything in control.

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Water Hyacinth