By the Editors of Ponds USA & Water Gardens
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Oxygenating plants are beneficial to the fish in the pond. These plants will also compete with algae. |
- Monitor the pond’s pH at different times of the day to make sure that oxygenating plants do not drastically change the pH throughout the day
- Goldfish and koi may eat some of these plants, but fast growth can compete with hungry fish.
- Crop back excess plants during spring and summer
- Remove dead stems in autumn
- Dispose of waste material correctly, as oxygenators may be invasive
- Make sure these plants are legal in your area
Canadian pondweed (Elodea canadensis)
- Tolerates cold, but it does not do well with mild winters and little change between seasons
- Can be grown rooted in pots or as a floating plant at the surface
- Needs bright light
- Fast growth in spring and summer
- Can grow to 4 feet long
- Can be invasive
Other Elodea species
- E. callitrichoides and E. nuttallii are two most popular species
- Elodea species are similar to Canadian pondweed in appearance and care
- Does not grow as fast as Canadian pondweed
South African curly pondweed (Lagarosiphon major)
- Doesn’t grow as quickly as Canadian pondweed
- Often sold under the Latin name Elodea crispa
- Care is similar to Canadian pondweed
Brazilian pondweed (Egeria densa)
- Also called Anacharis or Anacharis densa
- Also an aquarium plant
- Robust, bushy-looking plant
- Care similar to Canadian pondweed, but less tolerant of long, hard winters
- Can become invasive in temperate zones
Hornworts
- Floating plant that looks feathery, having a spiny, crispy texture
- The coontail (Ceratophyllum demersum) is the most popular hornwort species
- Will do well in any properly maintained ponds
- Flowers are small, produce quarter-inch fruit with spines
- Will die back during winter and will grow from the fruit when the weather warms
Water Milfoils
- Feathery-leaved
- Grow it rooted
- Needs good light
- Has whorls of white flowers that rise above the water
- Popular species include alternate-flower milfoil (Myriophyllum alterniflorum), European milfoil (M. spicatum) and whorled water milfoil (M. verticillatum)
- Tolerant of hot summers and cold winters
Curly pondweed (Potamogeton crispus)
- Not common
- Pink stems and large leaves (3 to 4 inches long)
- Grows rooted and can grow canopies that float just below the water surface
- Does not grow as quickly as Canadian pondweed
- Good for smaller ponds
Fanwort (Cabomba carolina)
- Feathery green or reddish-purple leaves
- Won’t survive freezing temperatures
- Soft and acidic water with not too much water flow
- Silty water ruins these plants
Water violet (Hottonia inflata and H. palustris)
- Don’t often do well in ponds
- Tolerant of cold winters
- White or purple flowers
- Plant in pots and put in bright spots
Willow mosses (Fontinalis spp.)
- Aquatic moss
- Fontinalis antipyretica most popular species
- Does well in ponds grown on rockwork or in gravelbeds with good water flow
- Grows slowly
- Good for small ponds