Elodea can help keep your pond healthy and your fish happy.

Elodea Information

by Megan Martin

Elodea (Elodea canadensis), also known as common water weed, grows in ponds in U.S. Department of Agriculture plant hardiness zones 5 through 9. Depending on how you use your pond, elodea can be a blessing or a curse. While it benefits pond life, when overgrown it can make even the most gorgeous backyard pond look unsightly.

1. Identification

Elodea is an underwater plant that has many branches and thin, dark green, waxy leaves. Unlike many water plants, elodea stays green, even in winter. It may also have waxy, white floating flowers.

2. Benefits

If you have a small backyard pond with fish, elodea may benefit the ecosystem. In moderation, elodea serves as a food source and gives fish hiding spots. It also feeds smaller insects and invertebrates that fish may eat. If your pond enjoys visits from small amphibians, elodea or the insects that eat it may attract them.

3. Problems

Dense growth of elodea is usually caused by excessive nutrients from overuse of fertilizers in your own or your neighbors' lawns. If you think fertilizer runoff is reaching your pond, avoid using fertilizer nearby. If your pond contains koi or other fish, too much elodea can reduce available oxygen and potentially kill them. If you think fertilizer is getting into your pond, you can build a barrier to keep runoff out of the pond. If fertilizers still get into the pond, the elodea will continue its fast growth rate.

4. Management

For small ponds, you can remove elodea by hand by reaching in and pulling up as much of the plants and roots as possible. To remove elodea from a larger pond, use a rake. Drag the rake across the surface of the water until you have pulled out as much as you want to remove. This will not keep elodea at bay permanently and you will have to remove it consistently. You don't need to use chemicals, and the chemicals may kill your fish.

Photo Credits

  • Ryan McVay/Photodisc/Getty Images