Invasive plants are listed in red boxes. Alternatives are listed below in green.
Invasive plants that are also a fire hazard are identified by this symbol:
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.
The fastest-growing plant in the world. Forms dense mats that impede water flow. Can double in a week in hot weather. Seeds can live 15-20 years. The Sacramento-San Joaquin Delta and several of its associated rivers are heavily infested.
commonly grown near wet areas. Persists year to year from root buds and from the root crown. Erect stems, 2 to 4 feet tall, produce purple flowers on spikes. Although not commonly sold in California, this plant is available for purchase on the internet. Invades streambanks and wetlands throughout the U.S. One plant can produce 2.7 million seeds. Has the potential to infest rice fields.
Ludwigia hexapetala, L. uruguayensis, L. peploides
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.
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.
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.
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.
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.
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.
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.
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.
'Alphonso-Karr' bamboo, 'Golden Goddess' bamboo or clumping bamboos
Bambusa multiplex 'Alphonso-Karr', Bambusa multiplex 'Golden Goddess' or Bambusa multiplex
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.
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.)
Submerged Plants. A rootless, deciduous perennial with slender stems and forked leaves. Tolerates shade and hard water. Good oxygenator.
common rush
Juncus effusus
Pond Margin Plant or Bog. A perennial rush with evergreen foliage. Easy to grow in wet spots. To 2˝ feet tall and wide. California native. J. effusus ‘Spiralis’ has coiled stems.
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.
Sagittaria latifolia, Sagittaria montevidensis or Sagittaria lancifolia
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.
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.
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.
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.
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.
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.
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.
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.
Lobelia cardinalis, Lobelia fulgens or Lobelia siphilica
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.
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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