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Yellow Water Lily (Spatterdock)


Ecological Importance

Fruits are eaten by waterfowl and muskrats; the underwater roots contain starch and are edible. Yellow Water Lily provides excellent habitat for largemouth bass and sunfish; highly decorative-often planted in water gardens. Yellow water lily also known as spatterdock, yellow cow lily, and pond lily.


Yellow water lilies (spatterdock) can grow and reproduce rapidly if not maintained correctly. This occurs when there is an excess of nutrients in the pond. With smaller ponds, water lilies can completely cover the surface in just a few short weeks reducing light penetration into the pond which can kill fish and other plants. Dense growth of yellow water lilies (spatterdock) in shallow water areas sometimes interferes with boating and recreation.

Plant Description

Spatterdock has large heart-shaped leaves, usually with wavy margins. Spatterdock floating leaves are attached to long, stout stems which arise from large, spongy rhizomes. Spatterdock submersed leaves are very thin, attached at the bottom rhizomes. Spatterdock flowers are yellow and "half-opened" at or above the water surface. Flowers are attached to thick round stems that are often six feet long. Spatterdock (yellow water lilies) reproduce through both seeds and rhizome spread.

Hints to Identify

Flower forms a yellow "ball" with petals that curve inward; flower rises several inches above water.

Homeowner Treatment Options
Imazapyr 4 SL
Renovate Max G
Shoreline Defense
Sonar AS
Sonar RTU
*Aquatic Biologists recommends implementing preventative management techniques and physical removal prior to, or in conjunction with treatment.


Common Application Questions

Q. When is the best time to treat?

A. Water temperatures ideally should be sixty degrees and above. Generally, as long as the plants are vibrant they will respond well to treatment.

Q. How often do I need to treat the Lilies?

A. Control can last anywhere from two to four years or more depending upon adjacent plant influence. Two applications may be required initially.

Q. How long before I see results?

A. Depending on the product used initial results will generally occur within ten days after which the edges will begin to yellow and curl. The plants normally drop from the water column within three weeks.