- Parrot’s Feather
- Parrot’s Feather
- Garden Plans For Parrot’s Feather
- Parrot’s Feather in Water Gardens
- Parrot’s Feather Care
- Parrot Feather Planting: Learn About Parrot Feather Plant Care
- Parrot Feather Information
- Growing Parrot Feather
- Parrot’s-feather Myriophyllum aquaticum
- Parrot Feather (Myriophyllum aquaticum): A Non-Native Aquatic Plant in New Jersey Waterways
- Impacts to the Aquatic Ecosystem
- Prevention and Control
- Mechanical and Physical Control
- Biological Control
- Chemical Control
- References and Resources
- Parrot Feather
- Mechanical Control
- Chemical Application Best Practices
- Ask an Expert
Parrot’s feather is a versatile plant for ponds and water gardens. Grow it underwater to oxygenate water, provide fish a place to hide, and reduce on algae. Or let parrot’s feather float on the water to provide shade. It can also be grown in wet soil at the water’s edge. It earned its moniker from its dense plumes of fine-texture foliage. Parrot’s Feather has both submerged and emergent foliage. The emergent stems will root near the shoreline via rhizomes.
Check local restrictions before planting parrot’s feather because it is considered an invasive species in some areas. It can reproduce rapidly in natural areas, clogging waterways and crowding out native species.
Garden Plans For Parrot’s Feather
Parrot’s Feather in Water Gardens
Its fine, almost fernlike texture makes parrot’s feather a beautiful contrast to lotus, water lily, and other big-leaf water-garden plants. It grows equally well in ponds and container water gardens.
Plant parrot’s feather with papyrus; its upright growing habit looks good with a carpet of low-growing parrot’s feather at the base. Or place parrot’s feather near water lily’s big, flat pads and attractive blooms to contrast with the fine texture of parrot’s feather.
The plant is especially useful for improving water quality: It efficiently absorbs excess nutrients, ensuring water purity and helping reduce the growth of unsightly algae. Unfortunately, it’s also valued by mosquitoes, who like to lay eggs around the plant as it floats in shallow water.
Parrot’s Feather Care
Parrot’s feather grows fastest in full sun (6 to 8 hours of direct light per day), but it tolerates sites with only morning sun. The less sun it gets, the slower it grows and the less efficiently it improves water quality.
In water gardens, plant its delicate rhizomes in soil in shallow water. It will quickly root and begin to spread. Its ability to root also makes parrot’s feather a good transitional plant for shorelines.
In cold-winter areas, parrot’s feather dies back to the rhizomes, so it should be pruned to the ground or water level after hard frost so the dead foliage doesn’t decompose over winter.
Get creative with these water garden landscaping ideas.
Parrot Feather Planting: Learn About Parrot Feather Plant Care
The attractive, feathery fronds of parrot feather plants (Myriophyllum aquaticum) often encourage the water gardener to use it in a bed or border. The delicate appearance of growing parrot feather compliments other foliage in your water feature or bog garden.
Parrot Feather Information
Stop: before you make the mistake of planting this seemingly innocent specimen in your landscape, you should know that parrot feather information indicates that these plants are highly invasive. Once planted, they have the potential to readily escape cultivation and overwhelm native plants.
This has already happened in numerous areas in the United States. Only female specimens of the plant are known to grow in this country and multiply from root division and plant pieces in a process called fragmentation. Tiny bits of the plant have moved through waterways, on boats and located themselves aggressively in many areas. Several states have laws that prohibit growing parrot feather.
Growing Parrot Feather
Growing parrot feather began innocently enough in the United States. The South and Central American native came to the country in the 1800’s to decorate indoor and outdoor aquariums. The attractive, feathery plumes of parrot feather plants took hold and began to choke out native plants.
If you choose to use parrot feather plants in your pond or water garden, keep in mind that parrot feather plant care will consist of keeping the plant under control. Keep growing parrot feather in bounds by only using in lined ponds and water features or in containers.
Parrot feather plants grow in fresh water areas from rhizomatous roots. Cutting the plant encourages it to grow, so control can be complicated if it grows to restrict your drainage pipe or begins to destroy beneficial algae. Aquatic herbicides are sometimes effective in parrot feather plant care and control.
If you choose to grow parrot feather plants in or around your water feature or pond, make sure it is legal to grow it in your area. Plant only in a controlled situation, such as a container or indoor water feature.
Parrot’s-feather Myriophyllum aquaticum
Banned From Sale after April 2014. A non-native invasive plant.
This very popular pond plant produces long stems and floating mats of attractive feathery leaves. It is still available from many outlets, where it may be sold as Brazilian water-milfoil, Myriophyllum brasiliense or Myriophyllum proserpinacoides.
What’s the problem?
It can root from small stem fragments and readily escapes into the wild, where its vigorous growth allows it to become dominant in ponds, lakes, reservoirs, ditches and canals. It grows to such an extent that it can choke water bodies and out-compete native vegetation, blocking light and altering patterns of flow. It is mainly sound in southern England but is spreading in the wild, possibly assisted by our warmer winters.
Rapid Risk Assessment
***** Critical Risk
Plantlife campaigned long and hard to have this species banned from sale. As of April 2014 it will be in England and Wales. This species is also listed on Schedule 9 of the Wildlife and Countryside Act in England and Wales therefore, it is also an offence to plant or otherwise cause to grow these species in the wild.
Removing parrot’s feather
Regular cutting (at least every 6-9 weeks during the growing season – cut more frequently if necessary) will help to weaken the plant. In your garden pond you can thin using a rake. Cut material must be removed from the water as soon as possible and all fragments need to be removed to prevent regrowth (or spread downstream if you are clearing an area of river). Careful pulling out of stems by hand will help eradicate small colonies and after cutting.
Parrot Feather (Myriophyllum aquaticum): A Non-Native Aquatic Plant in New Jersey Waterways
A member of the water-milfoil family Halogragaceae, Parrot feather is a perennial rooted aquatic plant that has both a submersed and an emergent form which can extend up to 30 cm (12 in) above the water surface. Submerged leaves are often decayed or limp with a more reddish appearance and are 1.5–3. 5 cm (0.5–1.5 in) long, with 10–15 leaflet pairs per leaf. Sturdy, sparsely branched stems grow up to 2 m long and 5 mm in diameter. When shoots reach the water surface, plant growth changes to a horizontal pattern with extensive lateral branching followed by vertical stem growth (Fig. 1). Emergent leaves are stiff, bright green to bluish green, 2–5 cm long arranged in whorls of 3–6 leaves around the stem (Fig. 2). The leaves themselves are divided into 12–35 leaflet pairs giving them a featherlike appearance (Fig. 3). They sprawl along the water surface or wet soil and can rise up above the water and look almost like small fir trees up to 30 cm (1 ft) tall. Tiny 0.5 mm, four sepal white flowers are produced on short stalks at the base of emergent leaves. In South America, male and female flowers are on separate plants, but in North America only female plants are produced. Plants spread by rhizomes and growth from plant fragments. Adventitious roots emerge from the stem nodes allowing the plants to grow vegetatively.
Parrot feather may be confused with bladderworts, hornworts and other leafy milfoils; however the stiff, finely-divided featherlike emergent leaves are distinctive.
Parrot feather is native to Central and South America and has been introduced into Southeast Asia, Australia, New Zealand, South Africa, Japan and North America. It was first introduced in the United States due to its attractiveness as an aquarium or water garden plant. In the United States it has spread to 26 states including Hawaii, as far north as New York, west to Washington State, and all southern states but widely distributed in Alabama, Arizona, Louisiana, Mississippi and Tennessee.
Parrot feather is found in slow-moving freshwater lakes, ponds, streams and ditches and responds well to a high nutrient environment. It will grow in shallow water and on wet soil along a shoreline, so is well-adapted to moderate water fluctuations. It tolerates some salinity and is able to colonize brackish coastal waterways. The plant grows best in an environment where light can penetrate to the bottom but can occur as a floating plant in the deep waters of nutrient rich lakes. The perennial rhizomes exhibit an annual growth pattern and shoots begin to grow rapidly after overwintering. In the fall, plants typically die back to the rhizomes. Parrot feather appears to prefer warmer, milder climates but is not seriously affected by frost; although in northern latitudes emergent shoots and leaves have been killed by a hard frost. Once established, Parrot feather usually persists despite variations in the environment.
Impacts to the Aquatic Ecosystem
Parrot feather has escaped cultivation and has spread into water bodies through intentional plantings and growth of plant fragments. The brittle nature of stems results in many fragments that root easily in moist soils to establish new colonies. Plant fragments with their robust leaves and stems, and thick waxy cuticle, can survive periods out of water. Fragments can spread by currents, water fowl, and by boats. Parrot feather is present year round and may provide cover but has very little food value for wildlife. It can form dense, monotypic stands that clog waterways, irrigation and drainage canals and can alter the physical and chemical characteristics of a water body through shading and by slowing the water flow. This dense growth leads to competition with native vegetation, potential flooding problems, and impedes recreational activities including boating, fishing, and swimming. Parrot feather has also been shown to provide excellent habitat for mosquito larvae.
Prevention and Control
While prevention of Parrot feather infestation is the best line of attack, in many cases it is too late as the species is already present. To help stop the spread of aquatic invasive plants including Parrot feather, some steps to follow include:
- Remove all plant fragments from the boat, propeller, and boat trailer to prevent introduction into new lakes and rivers.
- Rinse mud and debris from equipment and wading gear and drain all water from boat before leaving access area.
- Allow all equipment to dry for at least five days before transporting it to a new water body.
- Do not release aquarium or water garden plants into the wild; seal them in a plastic bag and dispose in trash.
Protecting water quality can help control overabundant aquatic plants and is best accomplished by limiting, reducing, or redirecting the input of external nutrients (primarily nitrogen and phosphorous) into waterways. Potential nutrient sources include runoff from lawns and golf courses, barnyards, agricultural fields, waste from livestock, pets and wildlife, and poorly functioning septic systems. Reductions can be achieved by planting low maintenance lawns, applying less fertilizer near waterways, using phosphorous free fertilizer, maintaining vegetated riparian buffers to absorb nutrients, increasing bank stability to reduce soil erosion, and maintaining proper aeration and good water flow. Not addressing the nutrient issues will lead to a perpetual need to control plant growth. The two challenges of Parrot feather control are to minimize damage to native plants and to develop a long term control.
Mechanical and Physical Control
Physical removal of Parrot feather is limited due to the plant’s ability to rapidly spread through fragmentation. Mechanical controls such as cutting, raking, and underwater rototilling tend to increase the rate of infestation. Hand-pulling small areas may be effective, but care must be taken to remove the entire plant including emergent shoots, submersed shoots, roots and rhizomes, as well as all fragments or regrowth will occur. Dredging is expensive and usually not feasible for management. Physical barriers prevent growth by shading the bottom but will inhibit native aquatic growth.
Lake water lowering (drawdown) is sometimes used in cold winter climates to control Parrot feather. In this method, the lake water surface is lowered by several feet to expose the bottom sediments and Parrot feather plants to freezing conditions. Drawdown has been shown to be effective in the winter when the exposed plants are frozen (Wersal et al., 2013). In New Jersey, any drawdown of a waterbody may be subject to permitting from the New Jersey Division of Fish and Wildlife: state.nj.us/dep/fgw/fishperms.htm#lowering.
Introduced biological organisms have had limited success in the control of Parrot feather. Triploid sterile Grass Carp (White Amur) are herbivores that consume aquatic plants, but find the tough woody stems and high tannin content of Parrot feather to be unpalatable, so they are not a control option. In South Africa and Argentina, native leaf-eating beetles like Lysathia spp. have shown some promise in significantly reducing shoot biomass (Cordo and DeLoach, 1982; Cilliers, 1999). There have also been instances of native fauna like the North American beaver reducing Parrot feather biomass through herbivory (Parker et. al., 2007).
Herbicides are the most common and effective means of controlling Parrot feather, but it is difficult to achieve complete control. Due to the waxy cuticle of the emergent leaves and stems which repels many herbicides, a surfactant mixed with the herbicide may be required that can penetrate this cuticle. Care should be taken when applying herbicide spray. Researchers have found that the weight of the spray can cause the plant to collapse into the water, allowing the herbicide to be washed off before the chemical can be absorbed into the plant (Washington State, 1994). Herbicide formulations that can be used to control Parrot feather include: 2,4-D and imazpyr (Excellent result; broad spectrum systemic); diquat and glyphosate (Good result; broad spectrum contact); triclopyr (Fair result; selective systemic); and endothall (Fair result; broad spectrum contact) (Wetherdahl and Getsinger, 1988; Madsen et. al. 2007). A more detailed review of aquatic pesticide use can be found in Rutgers Cooperative Extension fact sheet FS386, “Aquatic Weed Control” (Hart, 2001). Treatment is most effective when applied to young actively growing plants, and no herbicide has been shown to be totally effective without repeat applications. The most appropriate means of selecting a specific treatment plan is to consult a licensed aquatic herbicide applicator that can provide treatment options and associated cost. When using chemical controls remember the following guidelines:
- The algae must be properly identified. Most herbicides control only certain plant types as indicated on the product label. You should contact an herbicide applicator to determine the appropriate method.
- Consider the use of the waterway to be treated. Most herbicides restrict the use of water until the herbicide has been degraded, inactivated, or dissipated.
- In New Jersey, the Department of Environmental Protection administers the regulations regarding application of chemicals to waterways. Applications require a permit and certified applicator that can be found at nj.gov/dep/enforcement/pcp.
- Calculation of water area/volume to be treated is needed for proper dosage.
- Method of application may affect your choice if a certain type of equipment is needed for treatment to be effective.
- Timing is important when deciding which herbicide to use. It is best to treat early in the season when just beginning to grow and not firmly established. This will reduce the amount of algae needed to be killed and reduce the chance of fish kills due to low dissolved oxygen caused by decaying plants.
- Water temperature affects the efficacy of some herbicides. Apply herbidcide when algae is actively growing with a compatible temperature. Label recommendations should be followed.
References and Resources
Figure 1. (Left): Parrot feather showing growth form. Courtesy of University of Florda Center for Aquatic and Invasive Plants.
Figure 2. (Center): Growth of parrot feather, Myriophyllum aquaticum. Courtesy of Vic Ramey, University of Florda Center for Aquatic and Invasive Plants.
Figure 3. (Right): Photo courtesy of Mike Haberland.
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Parrot Feather is a submerged plant that frequently trails along the ground or water surface of ponds, lakes and canals. It is native to South America and blooms from the spring to fall. It is easy to see why this plant is called Parrot Feather: its delicate, feathery, bright green leaves grow in profusion. Leaves are oblong, deeply cut and feathery looking. The leaf color is bright blue-green. Like most Watermilfoils, Parrot Feather leaves are arranged in whorls about the stem. Its leaves are in whorls of four to six. Stems can be five feet long. Stems trail along the ground or water surface, becoming erect and leafy at the ends.
Parrot Feather can be removed by cutting and raking from the pond. It will regrow from remaining roots and seeds.
Pond Dye can be used to limit sunlight into the pond. With reduced sunlight, photosynthesis cannot occur so growth will be stunted.
Selective herbicides, such as Aquathol®, should be used to treat Parrot Feather.
Chemical Application Best Practices
Anytime you use chemicals treat weeds or algae, please keep in mind the following:
- Treat your pond in sections. Treat only half the pond’s surface at a time. During hot weather or when treating heavy growth, it is important to treat no more than ¼ of your pond at a time and wait the full 14 days before re-applying. This helps lower the risk of fish loss during hot weather or when treating heavy growth.
- Once the weeds have browned & died, use a weed cutter & rake to remove as much dead material as possible. This prevents an accumulation of dead plant material and muck.
- Take a proactive approach to pond management. Use PondClear™, MuckAway™ and Pond Dye to keep your pond looking great. For more information, see our article on the Airmax® Ecosystem™
Ask an Expert
If you are unable to identify your pond weed(s) using our Weed ID Guide, follow this article to email us a photo.