Don’t Plant a Pest!


Invasive Aquatic Plants in All Regions

  • Eichhornia crassipes (water hyacinth)

    Eichhornia_crassipes_ by By Wouter Hagens
    Eichhornia crassipes
    Eichhornia crassipes water hyacinth

    Reputed to be the fastest-growing plant in the world! Can double in size in a week during hot weather. Forms dense mats that impede water flow. Seeds can live 15-20 years. The State of California has spent $45 million over 15 years to control water hyacinth in the Sacramento-San Joaquin Delta.

    Invasive: Do Not Plant

  • Hydrilla verticillata (water thyme)

    Hydrilla verticillata
    Hydrilla verticillata hydrilla; water thyme; Florida elodea

    Illegal to sell or possess in California. Has arrived in California mixed with shipments of water lilies and as a mislabeled aquatic plant. Fragments quickly start new colonies.

    Invasive: Do Not Plant

  • Lythrum salicaria (purple loosestrife)

    Lythrum salicaria
    Lythrum salicaria purple loosestrife

    Invades streambanks and wetlands throughout the U.S. Persists year to year from root buds and from the root crown. Although not commonly sold in California, this plant is available for purchase on the internet. One plant can produce 2.7 million seeds. Has the potential to infest rice fields.

    Invasive: Do Not Plant

  • Ludwigia (waterprimrose)

    Ludwigia hexapetala
    Ludwigia hexapetala creeping waterprimrose; Uruguay waterprimrose
    Ludwigia peploides
    Ludwigia peploides floating water primrose; California waterprimrose

    Crowds out native plants and reduces water quality. Dense mats slow water movement and create habitat for mosquito larva, which can carry West Nile virus. Although there are native Ludwigia, do not collect them from the wild.

    Invasive: Do Not Plant

  • Iris pseudacorus (yellowflag iris)

    Iris pseudacorus_yellowflag iris flower_ JM Di Tomaso
    Iris pseudacorus
    Iris pseudacorus yellowflag iris; pale yellow iris

    Forms colonies along streambanks. Listed as a noxious weed in Nevada, Expanding in the Pacific Northwest. Uncommon in California, but causes serious problems in other regions with similar climates.

    Invasive: Do Not Plant

  • Salvinia molesta (giant salvinia)

    Salvinia_molesta_Issempa_Wikimedia Commons
    Salvinia molesta
    Salvinia molesta giant salvinia; karibaweed; water velvet; African pyle; aquarium watermoss; water fern; koi kandy

    Illegal to sell in the US. Floating mats up to 3 ft. thick reduce light and dissolved oxygen in the water so that few living things can survive. Common salvinia (Salvinia minima) may be sold, but species are difficult to tell apart.

    Invasive: Do Not Plant

  • Egeria densa

    Egeria densa
    Egeria densa Brazilian egeria; egeria

    Infests 7000 acres in the Sacramento-San Joaquin Delta. Aggressively invades natural waterways, displacing native aquatic plants and forming dense mats that impede water flow.

    Invasive: Do Not Plant

  • Myriophyllum spicatum (spike watermilfoil)

    Myriophyllum spicatum
    Myriophyllum spicatum spike watermilfoil

    The most widespread submerged invasive aquatic plant in California and a serious problem in Lake Tahoe. Stems are brittle and break easily, starting new infestations when spread by boats or water birds.

    Invasive: Do Not Plant

  • Myriophyllum aquaticum (watermilfoil)

    Myriophyllum_aquaticum_By André Karwath
    Myriophyllum aquaticum
    Myriophyllum aquaticum parrotfeather; Brazilian watermilfoil; parrotfeather watermilfoil; thread-of-life;

    Forms dense mats that impede water flow. Stems are brittle and break easily. Spread by boats or migrating water birds. Uncommon in California but has the potential to spread.

    Invasive: Do Not Plant

  • Arundo (aquatic)

    Arundo donax_Giant reed_ JM Di Tomaso
    Arundo donax
    Arundo donax giant reed

    A serious problem in coastal streams. Dense growth damages habitat, while creating a fire and flood hazard. Variegated varieties are also problematic and are not recommended.

    Invasive: Do Not Plant

Recommended Aquatic Plants

  • Sagittaria spp.

    Sagittaria latifolia arrowhead
    Sagittaria montevidensis
    Sagittaria montevidensis arrowhead
    Sagittaria lancifolia white swan, red swan

    Pond Margin or Bog . Striking arrow-shaped leaves and white flowers. Grows in moist soil or water 6 inches or more deep. S. latifolia grows 12 to 20 inches; S. montevidensis to 4 feet. Also try S. lancifolia (white swan or red swan) for a specimen plant with green or red stems and a 7-foot flower spike.

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  • Mimulus aquatics

    Mimulus guttatus
    Mimulus guttatus common yellow monkeyflower

    Pond Margin or Bog. Annual or perennial. Fills out a 4 feet x 4 feet space in spring and summer. May die back then return the next year. Yellow flowers with reddish spots resemble snapdragons. Hummingbirds like it; deer don't. Also try M. cardinalis for red flowers.

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  • Nuphar polysepalum

    Nuphar polysepala
    Nuphar polysepala yellow pondlily

    Floating or Rooted Emergent Plants. A native plant with a dramatic yellow flower and round leaves up to a foot in diameter. Foliage is submerged in winter and emerges in spring. May take more effort to find for sale.

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  • Polygonum amphibium

    Polygonum amphibium var. stipulaceum
    Polygonum amphibium var. stipulaceum water smartweed

    Submerged Plants. A versatile, creeping plant that does well in water depths ranging from moist soil to 4 feet of water over the crown. Long, narrow, floating leaves, and bright-pink flowers.

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  • Pontedaria cordata

    Pontedaria cordata
    Pontedaria cordata pickerel weed

    Pond Margins. Heart-shaped leaves surround dramatic flower spikes. Excellent filtration ability. Place in containers in 1 foot of water. 3 to 4 feet tall, 2 to 2 1/2 feet wide.

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  • Iris ensata

    Iris ensata 'Variegata'
    Iris ensata 'Variegata' Japanese iris

    Pond Margin or Bog

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  • Iris laevigata

    Iris laevigata and cultivars
    Iris laevigata and cultivars laevigata iris

    Pond Margin or Bog. A true water-loving iris that will do well in 6 inches of water. Flowers in white, purple, lavender, and pink. Yellow-blooming varieties are available, but rare. Leaves to 18 inches tall.

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  • Iris missouriensis

    Iris missouriensis, I. longipetala
    Iris missouriensis, I. longipetala western blue flag iris

    Pond Margins. A native iris with flowers ranging from white to blue to lavender. Leaves to 2 feet tall. Likes open, sunny, moist areas. Smaller in scale than yellowflag iris.

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  • Iris sibirica

    Iris sibirica and hybrids
    Iris sibirica and hybrids Siberian iris

    Pond Margin or Bog.

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  • Juncus effusus

    Juncus effusus common rush

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  • Ligularia wilsoniana

    Ligularia wilsoniana
    Ligularia wilsoniana Wilson's ligularia

    Pond Margin or Bog. A tall and showy wetland perennial with spikes of bright yellow, daisy-like flowers. Stems grow to six feet tall.

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  • Lobelia spp

    Lobelia cardinalis
    Lobelia cardinalis lobelia
    Lobelia fulgens lobelia
    Lobelia siphilica lobelia

    Pond Margin Plants. A spectacular blooming bog plant. Tubular flowers resemble honeysuckle or salvia and attract hummingbirds. L. cardinalis and L. fulgens to 6 feet with red flowers; L. siphilica grows 2 to 3 feet with blue flowers.

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  • Lysochiton americanum

    Lysochiton americanum
    Lysochiton americanum yellow skunk cabbage

    Pond Margin or Bog

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  • Marsilea spp.

    Marsilea spp. water clover

    Floating or Rooted Emergent Plants.

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  • Elodea canadensis

    Elodea canadensis
    Elodea canadensis waterweed

    Submerged Plants. One of the best oxygenating plants. Has dark green leaves and provides food and shelter for fish. Dies back in winter. Grows best in fine sand but may need to be controlled in small ponds. (Sometimes also sold under the name anacharis.)

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  • Brasenia schreberi

    Brasenia schreberi
    Brasenia schreberi watershield

    Floating or Rooted Emergent Plants.

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  • Ceratophyllum demersum

    Ceratophyllum demersum
    Ceratophyllum demersum coontail

    Submerged Plants. A rootless, deciduous perennial with slender stems and forked leaves. Tolerates shade and hard water. Good oxygenator.

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  • Chondropetalum aquatics

    Chondropetalum tectorum
    Chondropetalum tectorum Cape thatching reed

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  • Cornus sericea

    Cornus sericea
    Cornus sericea redtwig dogwood
    Cornus sericea 'Flaviramea'
    Cornus sericea 'Flaviramea' yellowtwig dogwood

    Pond Margin or Bog. Brilliant red or yellow foliage and colorful winter twigs. Provide good screens where water is present. to 8 feet tall and 10 feet wide. Cut roots to control spread.

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  • Alisma plantago-aquatica

    Alisma plantago-aquatica
    Alisma plantago-aquatica common waterplantain

    Pond Margin or Bog. Herbaceous perennial with flowers heads arranged in whorls of white, pink, or lavender. Blooms form a pyramid-like shape. Suitable for medium to large ponds, but may overwhelm a small one. 12 to 36 inches tall and up to 18 inches spread.

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  • Aponogeton distachyon

    Aponogeton distachyon
    Aponogeton distachyon cape pondweed

    Floating or Rooted Emergent Plants. Crisp white flowers with a vanilla scent are held on the water surface. Prefers cool water. May overwhelm a small pond.

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  • Azolla filiculoides

    Azolla filiculoides
    Azolla filiculoides Pacific mosquito fern, fairy fern

    Floating or Rooted Emergent Plants. Tiny, free-floating perennial fern. Excellent pond cover for fish and other wildlife. Turns reddish-purple in the fall. To 1/2 inch high, with a spreading habit. May overwhelm a small pond.

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  • Baccharis salicifolia

    Baccharis salicifolia mulefat

    Pond Margin or Bog.

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  • Bambusa aquatics

    Bambusa multiplex 'Alphonso-Karr'
    Bambusa multiplex 'Alphonso-Karr' 'Alphonso-Karr' bamboo
    Bambusa multiplex 'Golden Goddess'
    Bambusa multiplex 'Golden Goddess' 'Golden Goddess' bamboo
    Bambusa multiplex
    Bambusa multiplex bamboo (clumping species only)

    Pond Margin or Bog. Useful as a hedge or screen. Rhizomes of clumping species stay close to the plant and will not invade surrounding soil. Height varies by cultivar, up to 35 feet. Do not plant running bamboos, which spread aggressively.

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