Large or small, every garden pond can suffer from excessive algae growth under certain conditions. These plants may well be normal in moderation, but if they multiply to an extreme extent, they can affect the other inhabitants of the pond. We will tell you which pond plants have a cleaning effect and thus counteract the spread of algae.
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Purifying aquatic plants
Ultimately, algae are “only” plants, but with an extreme rate of reproduction and at the same time undesirable effects. Although various other plants rarely allow targeted action against an already existing, intensive algae growth, they help to ward off the beginnings and prevent the conditions for optimal algae growth. They do this through various measures, among which the absorption of nutrients from the pond water that are vital for the algae is one of the most important.
When choosing pond plants to protect against algae, you shouldn’t limit yourself to a single plant species, for example, underwater plants or water plants for the riparian zone – visual preferences aside. Despite the natural, thermally induced water circulation in the pond, there can otherwise be severe imbalances in the distribution of oxygen and nutrients.
underwater plants
The effectiveness of underwater plants against algae is probably the most obvious, as they thrive where the algae are intended to be prevented. During photosynthesis, they release oxygen, which is then released into the water. This oxygen contributes to good water quality and, for example, also promotes microorganisms that specifically counteract the growth of algae.
For low water levels around 20 to 40 cm water depth:
- Needle rush (Eleocharis palustris)
- Water Feather (Hottonia palustris)
- Milkhopper (Myriophyllum vertivillatum)
- Schwanenblume (Butomus Umbellatus)
- Tannenwedel (Hippuris Vulgaris)
- Pfennigkraut (Lysimachia Nummularia)
- “White-Green” (Shinnersia Rivularis)
- Water star (Callitriche palustris)
Pond plants for water levels up to one meter:
- Hornblatt or hornwort (Ceratophyllum Demersum)
- Common bulrush (Eleocharis palustris)
- Thick- leaved waterweed (Egeria Densa/formerly also known as Elodea Densa)
- Milkhopper (Myriophyllum aquaticum)
- Grundnessel (Hydrilla Verticillata)
- Flowerless swamp friend (Limnophila sessiliflora)
floating plants
Of course, floating plants are also among the aquatic plants that clean the pond. Because although they don’t contribute so much to the oxygen content of the pond water, they supplement the cleaning effect by intensively shading the pond with their mostly large-sized leaves or their large number of individuals. Sunlight is an elementary component of algae proliferation, so that the floating plants unfold a clearly growth-inhibiting effect. In addition, they are usually heavy feeders who simply deprive the algae of their food.
- Seerose (Fam. Nymphaea)
- Sea urchin (Fam. Nymphoides)
- Yellow water lily (Nuphar lutea)
- Froschbiss (Hydrocharis bite-frog)
- Three-furrowed duckweed (Lemna trisulca)
- Lesser Duckweed (Lemna Minor)
- Floating fern (Salvia natans)
- Thick- stemmed water hyacinth (Eichhornia crassipes)
- Swimming Wolf Milk (Phyllanthus Fluitans)
- Tufted fern (Limnobium auriculata)
swamp plants
Finally, one should not only include the free areas of the pond in the planning of algae freedom, but also not neglect the shoreline. In the transition area between land and water, however, marsh plants unfold their cleansing effect. Since they are only in the water-washed area with their roots, it is precisely this plant section of the aquatic plants that is responsible for the cleaning effect. The root network extracts nutrients from the water that would otherwise be available to the algae for uninhibited growth and thus ultimately contributes to its filtration.
- Binsen (Fam. Juncus)
- Igelkolben (Sparganius Erectum)
- Krebsschere (Stratiotes Aloides)
- Tube flasks (Typha Angustifolia)
- Common reed (Phragmites communis)
- Sumpfiris (Iris Laevigata)
Depending on the species, marsh plants either need real soil for their growth, or they can get by with common pond substrates. Here, before settling, it is worth obtaining information about the requirements of the specific plant in question.