Aquatic & Wetland Alternatives for Eastern WA
Below, you will find non-invasive alternatives to common invasive or noxious weeds.
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Purple Loosestrife and Garden Loosestrife
Full List of Recommended Aquatic & Wetland Alternatives
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Alternatives to Purple Loosestrife and Garden Loosestrife

INVASIVE: Purple Loosestrife and Garden Loosestrife
Lythrum salicaria & Lysimachia vulgaris
Class B Washington State Noxious Weed
Both garden and purple loosestrife are common additions to flower gardens. These invasive plants are a major threat to wetlands due to their ability to tolerate saturated soils and spread rapidly into non-disturbed areas. Purple loosestrife is notorious for forming dense, uniform stands; it crowds out all native plants and reduces wetland habitat. Garden loosestrife is a new but serious concern in both eastern and western Washington where it has been observed out-competing the noxious purple loosestrife in some wetlands.
More choices: Red columbine (Aquilegia formosa), hardhack (Spiraea douglasii), lady’s thumb (Polygonum amphibium), all of which are WA natives.
Learn more here:

Recommended Alternative: Gayfeather
Liatris spicata
Gayfeather is an eye-catching, purple-spiked perennial.
- Its tall spikes of purple flowers are similar in appearance to purple loosestrife.
- This plant blooms July through September, around the same time as purple loosestrife.
- Unlike purple loosestrife, it likes well-drained soils.
- Gayfeather takes full sun.
USDA Zones 3-9.
Image Courtesy of Alice B. Russell, North Carolina State University

Recommended Alternative: Jabob Kline Bee Balm
Monarda didyma ‘Jacob Kline’
The foliage and flowers of Jacob Kline differ from the loosestrifes but are wonderful in their own right.
• Cheery crimson, shaggy flower heads attract bees, butterflies, and hummingbirds.
• It blooms between June and July and provides excellent cut flowers.
• The habit is upright and spreading and can reach 4 feet in height.
• Deer reportedly do not like bee balm, so it may be useful to screen other plants.
• ‘Jacob Kline’ is very mildew-resistant.
USDA Zones 4-10.
Image Courtesy of Alice B. Russell, North Carolina State University

Recommended Alternative: Cardinal Flower & Hybrids
Lobelia spendens, L. x speciosa, L. x syphilitica, L. x gerardii
These striking plants are well suited to damp places.
• Bright red flowers are held in upright spikes above the foliage.
• Hummingbirds are attracted to the blooms.
• Some cultivars of L. splendens have deep purplish-maroon foliage.
• They behave as annuals or short-lived perennials but self-seed in moist soil without becoming weedy.
USDA Zones 3-9.
Image Courtesy of Alice B. Russell, North Carolina State University
Alternatives to Yellow Flag Iris

INVASIVE: Yellow Flag Iris
Iris pseudacorus
Class C Washington State Noxious Weed
With its showy yellow flowers and dense, lance-shaped leaves, yellow flag iris has been a popular addition to ornamental ponds and water gardens. However, this emergent wetland plant quickly spreads through underground rhizomes and rhizome fragments. It is naturalizing along streams, canals, and shorelines throughout Washington, particularly near developed areas. Yellow flag iris can completely displace native wetland plants along the shoreline. Its dense, root-like mat collects sediment and severely reduces water flow, affecting plants, fish, and other animals.
More choices: Arctic iris (Iris setosa), blueflag iris ( I. versicolor), I. virginicum, bearded iris (Iris x germanica), and native species Rocky Mountain iris (I. missouriensis), western skunk cabbage (Lysichiton americanum), and golden-eyed grass (Sisyrinchium californicum).
Learn more here:

Recommended Alternative: Japanese Iris
Iris ensata, ‘Variegata’ & cultivars
This is a beautiful iris for pond edges and bogs.
• It is ideal for wet boggy areas and is an easy to grow edge-of-pond plant.
• Elegant large flowers of white, purple, and violet-blue form in late spring and early summer, a little later than yellow flag iris.
• Foliage can reach 16 inches, and the scale of the plant is smaller than Iris pseudacorus.
• Foliage of the cultivar ‘Variegata’ offers a creamy white and green foliar accent to pond plantings.
USDA Zones 5-8.
Image Courtesy of Laura Burton

Recommended Alternative: Laevigata Iris
Iris laevigata & cultivars
Laevigata iris is a true water-loving iris which is beautiful in and out of flower.
• This plant is an ideal replacement for yellow flag iris in pond plantings. Laevigata iris will grow well in 6 inches of water. It is also good for wet boggy areas and is easy to grow.
• Its flowers are large white, purple, lavender, and pink. Yellow blooming varieties are rare.
• This plant blooms later than yellow flag iris.
• Foliage can reach 18 inches, so the scale of the plant is smaller than yellow flag iris.
USDA Zones 2-9.
Image courtesy of Pat Woodward, Pacific Rim Native Plant Nursery

Recommended Alternative: Siberian Iris
Iris sibirica & hybrids such as ‘Butter & Sugar’, ‘ Sunfisher’ (both yellow blooming)
Siberian iris is a very versatile, easy-to-grow iris and the perfect choice, other than a bearded iris, if you want yellow flowers.
• It is good for mixed borders with normal water needs; also suitable for damp sites, but not for standing water.
• The flower colors range from white to purple to blue-purple to yellow.
• With foliage usually 2 feet or less, and taller flowers, the plant is smaller than yellow flag iris.
• Blooms May-June, but its lovely foliage makes this iris beautiful in and out of bloom.
USDA Zones 4-9.
Image courtesy of Pat Woodward, Pacific Rim Native Plant Nursery
Alternatives to Parrotfeather

INVASIVE: Parrotfeather
Myriophyllum aquaticum
Class B Washington State Noxious Weed
This South American native has been a popular plant for ornamental ponds as its emergent stems are bright green and attractive, and its submerged stems act as a natural filter and provide oxygen for fish. Like many nonnative, invasive aquarium and pond plants, parrotfeather has been carelessly released into our natural aquatic systems where it forms dense mats that out-compete native submerged plants and can reduce water flow. Until recently, escaped populations were limited to areas west of the Cascades; however, at least one new population has been documented in eastern Washington.
Please remember, never dump water garden or aquarium plants and fish into natural water systems.
Learn more here:

Recommended Alternative: Mare's Tail
Hippuris vulgaris
Mare’s tail is an attractive native plant with a similar habit to parrotfeather.
• Stiff emergent stems are 6 to 12 inches tall with whorls of small, rigid, needle-like leaves.
• Submerged stems are softer with longer, more flexible whorled leaves.
• It prefers shallow, non-acidic, cool water.
• This plant can be propagated through stem cuttings and can spread through rhizomes.
• It prefers full to part sun.
USDA Zones 4-9.
Image courtesy of San Marcos Growers

Recommended Alternative: Coontail
Ceratophyllum demersum
Coontail is an excellent, easy-to-grow, oxygenating plant for ornamental fishponds.
• Submersed plants lack true roots but stems can be anchored to the substrate or left loose.
• Whorled, needle-like leaves cover the stem and are densest at the tip.
• This plant provides habitat, oxygen, and some filtration for fish.
• It is tolerant of frost.
USDA Zones 4-10.
Image courtesy of Richard Old, www.xidservices.com

Recommended Alternative: Canada Elodea
Elodea canadensis
This plant is a submersed native that does well under a variety of conditions.
• Bright-green leaves are whorled around stems in groups of three.
Careful! The noxious weeds Hydrilla and Brazilian elodea look similar. The leaves of Canada elodea appear in whorls of three. Hydrilla and Brazilian elodea leaves appear in whorls of four.
• Small, white flowers appear between June and September above the water’s surface.
• It is native throughout much of the United States and Canada.
USDA Zones 5-10.
Image courtesy of Richard Old, www.xidservices.com
Full List of Recommended Aquatic and Wetland Alternatives

The following is a list of recommended plants for wetland and aquatic areas in Eastern Washington. You can find more suggestions of non-invasive plants from your local nursery, WSU Master Gardeners, and at www.GreatPlantPicks.org.
- Gayfeather, Liatris spicata
- Jabob Kline Bee Balm, Monarda didyma ‘Jacob Kline’
- Cardinal Flower & Hybrids, Lobelia spendens, L. x speciosa, L. x syphilitica, L. x gerardii
- Red columbine, Aquilegia formosa
- Hardhack, Spiraea douglasii
- Lady’s thumb, Polygonum amphibium
- Japanese Iris, Iris ensata, ‘Variegata’ & cultivars
- Laevigata Iris, Iris laevigata & cultivars
- Siberian Iris, Iris sibirica & hybrids such as ‘Butter & Sugar’ Sunfisher, both yellow blooming
- Arctic iris, Iris setosa
- Blueflag iris, I. versicolor, I. virginicum
- Bearded iris, Iris x germanica
- Rocky Mountain iris, I. missouriensis
- Western skunk cabbage, Lysichiton americanum
- Golden-eyed grass, Sisyrinchium californicum
- Mare's Tail, Hippuris vulgaris
- Coontail, Ceratophyllum demersum
- Canada Elodea, Elodea canadensis