How to Grow and Care for Myriophyllum

Parrot's feather (*Myriophyllum aquaticum*) is a perennial that gets its name from its leaves, which are vaguely reminiscent of a parrot’s feathers. It comes from the Amazon River basin in South America. However, it has been imported to every continent on the planet, except Antarctica. It came to North America in the nineteenth century, first reported in the United States in the 1890s.

Alternate water milfoil is an aquatic plant found growing submerged in streams and ponds. It is considered invasive in many temperate regions because it removes vital oxygen from the water it inhabits and obstructs water flow. It spreads quickly via vegetative stem fragmentation.

Whorl-leaf watermilfoil is an aquatic species that grows primarily in slow-moving or still waters and is hardy enough to overwinter even under ice. Unlike many aquatic plants, all of its leaves remain submerged in the water. It is considered invasive in some areas; in others, whorl-leaf watermilfoil offers advantages because it helps oxygenate the water and creates a refuge for young fish and amphibians.

Widely distributed in almost 60 countries, the spiked water milfoil (Myriophyllum spicatum) is an aquatic plant that can be extremely invasive. Spiked water milfoil can crowd out the native plants and damage the habitats of native fish.

Twoleaf watermilfoil is a fast-spreading water plant that is classed as an invasive species in locations such as the state of New England, USA. Its import and sale are banned in the European Union. An Eastern USA native, this plant has spread across many countries in Western Europe and its profuse growth starves ponds and lakes of light and oxygen. In good conditions, this plant's stems can grow as quickly as 2.5 cm per day.