Vallisneria, also known as eel grass or wild celery, is a freshwater aquatic evergreen perennial that is somewhat tolerant of salty conditions, albeit with lessened growth. It belongs to Hydrocharitaceae, the tape grass family, a largely tropical family that includes frogbit.
Vallisneria americana is, as its specific epithet may indicate, native to North and South America. However, it also occurs in portions of Asia (China, Japan, India, and Korea), where it’s considered naturalized and not invasive.
Nowadays, Vallisneria is most often cultivated and sold for the aquarium and pond industry. Its lengthy, flowy leaves make it both attractive to look at while also providing shelter for fish. The small, white or green flowers that float atop the water’s surface during the summer add to its appeal.
Facts, Benefits & Uses of Vallisneria americana
In nature, Vallisneria is an incredibly ecologically valuable plant. Typically found growing in calm waters like slow moving rivers, streams, lakes, and ponds, the long leaves help filter water while the root bundles and runners help stabilize sediment and banks.
Vallisneria americana is such an important food source to the canvasback duck that its Latin name, Aythya valisineria, was derived from the plant. Canvasbacks have been known to completely alter their migration routes so that they can rest at areas where there is Vallisneria to feed on. Other waterfowl and turtles also feed on the roots, tubers, shoots, and seeds of this plant, as well as aquatic insects that use the leaves for habitat.
Vallisneria americana Growth, Hardiness & Climate
Vallisneria is a fast grower, able to reach full height in two months of optimum lighting (full or partial sun) and pH conditions are provided. Typically, this plant will reach a maximum of three feet in height, with green, flowing leaves that range anywhere from an eighth of an inch to half an inch wide.
Once maturity is reached, small white or green 3-merous flowers will emerge from the tops of thin stalks and float atop the water. After pollination, the stalks coil and pull the flowers underwater, where they develop into fruits and eventually drop seeds. Dispersal is achieved via these seeds as well as stolons, which are less tenacious (and thus less potentially harmful) than rhizomes when spreading. Stolons are also much easier to cut and remove if you find that the plant is propagating more than you’d like.
Vallisneria do best in warmer conditions, so they can struggle in colder regions such as Britain, Canada, and the northern U.S. They can still both be found in nature and planted in these areas, but they may not grow as quickly or produce as many flowers. In mild areas, flowering can occur from April through September, but in cooler regions may be restricted to the warmest portions of summer.
If you’re growing Vallisneria from seed, the seeds should be simply placed atop well-draining soil in a pot. The pot can then be placed in water (but not submerged) to provide the seedling with ample moisture as it establishes a root system. Be sure to have this pot in a warm area, in a greenhouse (there are easy to build miniature greenhouse options available for those with limited space) if necessary. Move them to a pond or tank in the spring, after the last frost if outdoors.
If purchased as an already established plant, simply anchor the plant to the bottom of your pond on aquatic substrate, like gravel or sand. You can cover the roots gently, making certain to not cover the crown of the plant (this is the bottom inch or two of the leaves, which are noticeably lighter in color). Covering the crown will likely result in the plant dying, or stunted growth at the least. The roots should take hold within a week or two, at which point anchors, if used, can be removed.
These fully submerged plants need at least a foot of water to allow for proper growth, but can be planted in waters that are several meters deep so long as they’re still getting plenty of sunlight. Our advised depth range is 1 to 4 feet to ensure that your plants are getting enough direct or diffuse light to ensure proper growth. If you’d like to prevent these plants from putting out runners, you may consider placing them in aquatic baskets, though this isn’t necessary as new growth is easy to remove.
How to Care For Vallisneria americana
Suitable for beginner and veteran ponders alike, Vallisneria is considered one of the easiest aquatic plants to take care of. Provide at least 5 hours of sunlight per day, and make sure that you keep the pH above 6 as Vallisneria does not do well in acidic conditions. Other than that, just trim the stolons back as desired and you’re good to go! As always, be sure to clean up any trimmed or dropped foliage as needed to help maintain healthy water quality.
How to Winter Vallisneria americana
Vallisneria americana doesn’t need any special treatment to prepare them for winter. Any dropped seeds will remain dormant and safe until spring, while established plants will die down to tubers that were produced during the summer. These tubers are very energy rich due to the plant cleverly allocating much of its energy to them prior to winter hitting. Typically in March or April, the tubers will begin sprouting new plants. Waterfowl, particularly canvasbacks, are known to feed on these energy-rich tubers during spring migration.
Is Vallisneria Toxic, Poisonous or Invasive?
Vallisneria, as evidenced by its palatability to fish, ducks, and insects alike, is not toxic. While it’s not particularly tasty to us, it can technically be eaten by people as well. The tubers in particular can provide a valuable energy source in times of great need, if for whatever reason your find yourself lost outdoors and are able to find some eel grass.
There is little data on the invasiveness of Vallisneria. However, having any plant outside of its native range can pose threats to native ecosystems. Therefore, if you live outside of its native North and South American range, do exercise caution when planting to prevent it from spreading to natural areas and disrupting ecosystems. If grown outdoors, do use aquatic planting baskets to help deter spread via stolons, and make sure to plant only in garden ponds rather than natural ponds, lakes, or rivers where the native flora and fauna will be disrupted by its presence.
Is Vallisneria americana Edible? Will Fish Eat it?
Some fish, goldfish in particular, find Vallisneria leaves to be quite palatable. This shouldn’t be much of an issue, as typically this plant grows quickly and may benefit from some ichthyoid pruning to help control overgrowth. Eel grass leaves are also surprisingly tough, so it’s quite unlikely that fish would decimate it.
Where to Buy Vallisneria Plants & Seeds? (UK & US)
Vallisneria is easily and cheaply purchased from a variety of aquatic nurseries, pond and aquarium retailers (including aquarium fish shops), and online outlets.
In bc, Canada, 25’w x 35’l x 3.5’d, pond naturally fed in dec/jan then by cistern water to keep levels up. Have a lot of green algae, looking for pond plants that provide oxygen and kell off algae, any suggestions