Grow and Care for American Eelgrass

Grow American eelgrass fully under sunlit freshwater. American eelgrass is Vallisneria, also sold as tape grass and wild celery. It is not the marine eelgrass of salt bays.

Keep it fully under sunlit freshwater

American eelgrass has to stay under water. Full sun or part sun in a freshwater pond is the usual home, and about five hours of light keeps the ribbon leaves green. [1] The leaves grow in a cluster from a short crown, not along a long stem. They are flat and tape-like, with rounded tips and a raised midrib, and the upper ends may trail on the surface in shallow water. [2] [3] Crowns that dry on a bench do not recover. In cold winters the tops collapse and the plant lives on winter buds, sometimes called tubers, then new leaves rise in spring. It is not a dry-bed grass.

Plant with the crown uncovered, a foot or more under water

Shop plants arrive as a rooted crown. Keep them wet from the bag to the pond. Set the roots in sand, fine gravel, or aquatic soil, and leave the pale base of the leaves uncovered. If you bury that crown, it rots. In a home pond, at least a foot of water over the crown is enough, and one to four feet is the usual range so light still reaches the leaves. A mesh aquatic basket slows runners if you need the stand to stay in one spot.

1. Keep the plant wet from the bag to the pond. Discard mushy leaves in the trash, not in a ditch.
2. Push the roots into sand, fine gravel, or aquatic soil. Leave the pale crown, the bottom inch or two of the leaves, in the open water.
3. Lower the plant so at least a foot of water covers it. One to four feet is the usual home-pond depth.
4. Use a mesh aquatic basket if you need to slow runners. Cover the soil with a little gravel so fish do not root it out.
5. Bag extras. Do not toss crowns, runners, or mud into a lake, a ditch, or a storm drain.

Snap runners for new plants, and bag extras

New plants start from runners that creep along the pond floor, not from a seed packet. Wait until a daughter has its own leaves, then snap the runner and replant that crown the same way, or bag it. Clip extras before the stand mats the surface, and bag every piece you do not keep.

1. Wait until a daughter has its own cluster of leaves.
2. Snap or cut the runner between the parent and the daughter.
3. Replant the daughter with the crown uncovered, or bag it the same day.
4. Bag what you do not keep. Runners start new plants in the next pond they reach.

Not marine eelgrass — and not pond arrowhead

Marine eelgrass is Zostera, a seagrass of salt bays, not this freshwater plant. A tag that says eelgrass on this shop card is still American eelgrass. Pond arrowhead is Sagittaria, with pointed leaf tips and three white petals on a stalk above the water — see How to Grow Pond Arrowhead. Tape grass has rounded tips and a raised midrib, and the female flower stalk coils after pollination. [4] American bur-reed is Sparganium, an emergent with round bur heads — see How to Grow American Bur-Reed. Hydrilla and Canadian waterweed have small leaves in whorls on a stem, not a basal ribbon cluster — see How to Grow Canadian Waterweed. Tank light and a gravel crown are on American Eelgrass in an Aquarium.

Keep American eelgrass fully under sunlit freshwater, set the crown uncovered a foot or more deep, and bag extras instead of tossing them into a lake.