Oxygenating, floating, and bank plants: understanding their role in the natural balance of the pond according to Aquazolla
F. MattierFor a balanced pond, with or without fish, aquatic pond plants play an essential and irreplaceable role. Let’s discover together how their missions are distributed.
Because between the oxygenating plants, the floating plants, and the bank plants, roles and locations are precisely distributed.
It is the whole that creates an autonomous and harmonious ecosystem, aesthetic and sustainable, as advocated by Aquazolla.
Why aquatic plants are essential to the pond’s balance
No plant does everything! But all together, they cover all the ecosystem functions that facilitate maintenance and the natural biological balance of the pond.
Oxygenation, anti-algae, and natural purification
Oxygenating plants are those whose leaves are submerged.
Even if they sometimes end up protruding from the surface, all parts that are underwater oxygenate the pond water.
The more light they receive, the more they grow by producing oxygen and consuming nitrates.
This is how they purify the water, much better and more completely than pond filtration.
By purifying the water, they fight algae by competing with them and depriving them of nutrients.
Regulation of light and temperature
Floating plants like the famous three-lobed duckweed or floating frogbit do not oxygenate the water, since their leaves are above the water.
On the other hand, they help oxygenating plants purify it, since their roots are underwater and absorb nitrates and phosphates.
But above all, they filter the light and thus help moderate the water temperature during heatwaves.
The key is to know how to contain them, so they don’t cover the entire surface!
This is especially true with the magnificent Azolla, for example.
Stabilization of the bottom and edges, attraction of biodiversity
Finally, the bank plants are complementary, since they are almost entirely out of the water.
But their sometimes strong roots, like those of iris or purple loosestrife, hold the soil of the banks.
Smaller, they cover the ground and thus protect it from erosion, like the pretty water mint for example.
These plants flower very easily and thus attract a whole entourage of insects: pollinators, butterflies, or dragonflies!
Focus on the major families of pond plants
Oxygenating plants
The principle: they have access to depth and grow in open water.
Roles: natural purification, oxygenation, capture of excess nitrates, algae control.
Examples: elodea, Hornwort, Egeria najas, Water milfoil, Najas…
Aquazolla Tip: vary species, most do not need to be planted in the soil. Make sure they have light penetrating the water.
Floating plants
The principle: they float on the surface, roots in the water and leaves in the air.
Roles: natural purification, refuge for microfauna and fry, capture of excess nitrates, algae control, regulation of light and water temperature, aesthetics.
Examples: floating frogbit, duckweed, large duckweed, Azolla, three-lobed duckweed…
Aquazolla Tip: be sure to limit the occupied surface to let light through, vary species to increase biodiversity.
Bank plants
The principle: they only have their feet in the water or in the wet soil of the banks.
Roles: bank stabilization, bank filling, ground cover, refuge for biodiversity (frogs, insects, toads…), colorful flowering.
Examples: marsh iris, purple loosestrife, water mint,
Aquazolla Tip: vary plant heights, so that tall flowering plants (iris, purple loosestrife) rise above lower vegetation.
Also consider: ground cover plants
How many plants to plan for in a natural pond
- Make sure to have the three families so that all functions are fulfilled in the pond ecosystem.
- Choose the maximum number of different species to increase your chances that several will succeed and establish themselves sustainably.
- Plant abundantly: the fight against algae or green water is only won by the natural filters that are plants. No artificial filtration can do this. The more plants there are, the more algae will be disqualified.
- A heavily planted pond is a reassuring oasis for many small garden animals: toads, hedgehogs, birds, etc.
Aquazolla selection: our pond plants to prioritize if you are a beginner
3 oxygenating plants:
- Elodea: powerful anti-algae, very fast growth, no need to plant it in the soil.
- Hornwort: dense refuge for aquatic microfauna, fast growth.
- Crisped Water milfoil: truly original, it sticks its head out of the water and grows fast.
3 bank plants:
- Marsh iris: very strong roots to hold the bank, magnificent yellow flowers in spring, medium growth.
- Purple loosestrife: superb and long-lasting pink-mauve flowers, fast growth.
- Lobelia: long blooming intense red, medium growth.
3 floating plants:
- Three-lobed duckweed: naturally feeds your fish and shades the water, very fast growth.
- Azolla: creates a sumptuous velvety carpet on the surface, very fast growth.
- Floating frogbit: very long diving roots, original, medium growth.
3 ground cover plants:
- Aquatic mint: fragrant, its melliferous flowers attract pollinators, medium growth.
- Marsh isnardia: reddening and dense foliage, fast growth.
- Water hyssop: medicinal, "succulent plant" appearance, pretty flowers, medium growth.
Aquazolla tips for a healthy pond:
👁️Observe constantly: it’s a pleasure, and it will help you better understand your pond as a harmonious whole.
🐌 Think of auxiliaries: water lice or freshwater snails are an essential link between organic waste and plants, by decomposing them. They are the pond cleaners. Here too, vary the species as they will be complementary.
🦔 Make sure some gently sloping banks allow an animal that has fallen into the water to get out easily: hedgehog, young clumsy bird, etc.
🌞 Do not let floating plants take over the entire surface. The oxygenating plants would then have no light to function.
🐟 If you have carp or goldfish, they will regulate three-lobed duckweed by eating it, as it is an essential and valuable food for them (including the aphids it often attracts!).
FAQ — Oxygenating, floating, and bank plants (Aquazolla)
➡️Should all categories of plants be put in a pond?
Yes, they are all complementary: oxygenation, shading, filtration, bank stabilization, aesthetics, and shelter for aquatic and terrestrial biodiversity.
➡️Are oxygenating plants enough to purify the water?
They contribute strongly, but must be combined with floating and bank plants for a complete cycle. The roots of floating and bank plants also absorb a lot of nitrates.
➡️Which plants should be avoided in a pond?
Some plants are prohibited because they are likely to be invasive in nature. This is the case with water lettuce (the Pistia), which is forbidden to sell, give away, or exchange.
➡️Do bank plants attract insects?
Yes, and it is beneficial: they participate in pollination and serve as refuge for amphibians. They attract dragonflies whose aquatic larvae will get rid of mosquitoes for you!
➡️Should aquatic plants be fertilized?
No, aquatic microfauna and natural waste are more than enough for their growth. If you fertilize, you will first help the algae that your plants work every day to starve!
➡️What to do in winter ?
Bring back plants that cannot tolerate the cold or plant them deeper. Make sure your fish and plants have spots deep enough to overwinter safely beneath the surface ice layer.