NON-NATIVE NOXIOUS
THE FRAGRANT WHITE (and pink) POND LILY
Nymphaea Odorata
pond_lily
Non-Native Noxious Invasive Fragrant White (and pink) Pond Lily - Photo 8977 - Nymphaea Odorata
June 14, 2010
The fragrant white (and pink) pond lily (nymphaea odorata) has recently been introduced to the sunny part of our lake water at both the dam end and at Otter Run. This plant and the Yellow Flag Iris are classified as Class C plants, the most invasive noxious weeds. Now that it may photosynthesize at an accelerated rate it could take over our lake quickly. According to the Department of Ecology, shallow lakes are particularly vulnerable to being totally covered by fragrant pond lilies within twenty years. Their dense growth can inhibit swimming and boating, as well as result in low levels of dissolved oxygen, negatively affecting fish. (See http://www.ecy.wa.gov) Yes, the native watershield and yellow pond lily that have been here for years are numerous, but it could be worse. The entire lake could be without visible water. Someone admiring this pretty pink and white lily, not knowing of its invasive characteristics, probably planted it. It is now in the sun and growing rapidly.
Of all ways of eradicating this noxious weed, cutting and harvesting them several times a year is the most feasible for us. Herbicides require getting permission and hiring someone with a herbicide permit. This and covering them with an opaque fabric and anchoring it on the lake bottom takes much time and expense, and therefore doesn’t seem satisfactory.
lake_weeds
lake_weeds
Photo above is of patches that drifted into the sun and are a threat. At left are patches that have been there for several years and below are Yellow Flag Iris, also a noxious weed on the shores of our lake.

In 2010 the LSCC Board approved of a committee of volunteers to harvest (cut flowers and pads on the surface) the lilies in the sunny part of the lake (not those on the shoreline) several times during the summer to keep them from spreading. For the last two summers volunteers have cut and removed the large weed patches three times each season. We collected all loose plants as we did not want them to float elsewhere to propagate. This has not eradicated these lovely invasive water lilies, but has kept them from spreading in size and to other parts of the lake.

For more information on aquatic plants, the Washington Department of Fish and Wildlife has a pamphlet called Aquatic Plants & Fish: Rules for Aquatic Plant Removal and Control. You can see it here.

If you see this lily, in areas other then those mentioned, please contact me, Renee Bellemere (830-4231; rbellemere@wavecable.com).