Pond Boss Forums AQUATIC VEGETATION Balance of plants in the environment Eelgrass

HELP WANTED: Does anyone else have eelgrass / wild celery in their pond?
Give us your comments and experiences.

Larry - Your answers will help me formulate my comments about using eelgrass in your pond.

I am familiar with Vallisneria americania since I have had it growing in my two ponds for several years (abt 6 yrs now).
It is also called wild celery or tape-grass.
It is an oxygenator in the pond but most oxygen in all ponds comes from the phytoplankton community which grows in illuminated upper zone and limits light visibility in most ponds to 1-3 ft deep. These guys are the real oxygenators of aquatic systems.
Two of the sources I have says the eelgrass leaves can get 6 to 7 ft long. I have not seen it get longer than 24" to maybe 30" in my ponds. Your observation of it growing abt 5 ft long in the river agrees with the first two books I have.
I think I have two varieties or growth forms in my pond. One has a little wider & longer leaves and does not grow as densely but seems to grow a little deeper than the second type. Second type, has shorter leaves 6" to 18" grows in dense beds; some of the leaves in shallow water have a reddish hue. It grows about canoe paddle deep (5Ft.) Smaller pond water has visibility abt 2-3ft; clearer in fall, winter & real early spring.
There are two other types of Vallisneria in books/cataloges; both are said to grow as far north as zone 6 (considered tropical). Jungle - which has wide leaves abt 1" and corkscrew which has narrow twisted or spiral leaves. Corkscrew is supposed to have a maximum heigth of 8-12". Both are sold usu as aquarium/water garden plants. I've been experimenting with corkscrew for about a year and I did get it to overwinter in my pond, growing it in a dish pan (zone 5) under 2 months of ice cover. A neighbor has jungle eelgrass growing in his pond for about 4 years now. His jungle has leaves 2.5-3 ft long and grows in about 4-5 ft deep. His bed is about 40 ft long after 4 yrs; starting with several plants. His water has been abt 2-3 ft vis.
I am convinced that eelgrass will grow in water 10-12 deep probably deeper if the water is very clear. I don't see this as a problem if the plants stay short. Like with corkscrew eelgrass max height 12". Keep in mind that it will send scattered small 1-2" long flower "pods" to the surface onlong thin spiral stalks regardless of its growing depth. These are not a nuisance in my opinion; they only add fish cover and are at the surface for only about a month.
The book I have "Water Plants for Missouri Ponds" says that "Any fishing pond would benefit for a healthy stand of wild celery. This is one of the few submerged plants that provides good fish habitat but dosen't become rampant or interfere with fishing. Because it grows thickly it may even crowd out other less desirable underwater plants." I agree with this. It crowds out curly leaf pond weed in one of my ponds and the curly leaf is forced to grow in the deeper water; eelgrass dominates the shallow water. In the other pond it is crowding out beds of Chara.
In my old pond (which was rebuilt 3 yrs ago) now called the new pond, I had eel grass, narrow leaf pondweed & Chara. White amur ignored the eelgrass until spring then they "mowed" it all off across the bottom & I dipped most of the leaves out each spring. Amur must not have been able to eat many of the leaves and lots of it got away from the fish. I don't think eel grass is a favorite food of amur but they will eat it when nothing else is avilable. So eelgrass if too thick could be thinned or eliminated by amur depending on how many fish are in the pond.
With a thick stand of eelgrass in my pond I have no filamentous algae. Eelgrass seems to use most all the nutrients none left for algae. Eelgrass would not work if you fertilized your pond; the plants would prob. prevent a bloom. But I think dense beds of eelgrass use most of the nutrients from the fish manure from fish food. You can't plant eelgrass in a pond with amur; they eat it as fast as it is planted; my friend have tried this.
I think eel grass is excellant cover for small fish/minnows. Both of my ponds always have abundant minnows/shinners and fingerlings. Most every pond around me cannot keep minnows in them due to lack of weed beds, even though they have rip rap concrete along the sides and water lilies.
Eelgrass spreads pretty slowly but not as fast of many of the other pond weeds/filamentous algae types.
A Michigan State University Fisheries dept professor likes eelgrass for sportfish pond/lakes; he said fish can hunt thru it. It does not get to be a tangled mass like so many other pond weeds.
Larry, if I lived farther south like you I would seriously try to plant some of the corkscrew eel grass. It stays shorter and may not ever be a pest at all. It could provide a living rug 8-10" high all across the bottom of your pond and not allow many other weed types to get started or grow. You can always plant the longer "wild" type later if you see a need.
If you plant it, don't expect it to grow fast at all, it spreads slowly. I'd guess about 2-6 ft each year. If you want it to be all around your pond you'll have to plant it in numerous spots along the perimeter. B. Cody - Pond Doctor