Collection: Pond Plants

There are many plants that help clean pond water, and they can generally be broken down into two main categories: oxygenators and nitrate filterers. Oxygenators are plants that release oxygen into the water and compete with algae for resources, reducing the latter’s presence in the pond as a result. An excess of nitrates in a pond can lead to algal blooms, and while all pond plants filter nitrates out of the water, some are better than others as they’re faster growing and can therefore remove nitrates at a greater rate. Watercress and flag irises are two good examples.

Yes, you can have too many oxygenating plants in a pond. While oxygenating plants are generally beneficial for a pond, helping to keep it clean and free of algae, too many can actually lead to depleted stocks of oxygen within the water, which can affect wildlife like fish living within the pond. If you see a sudden increase in algae and start smelling an unpleasant odour, your pond may have too little oxygen.

The best time of year to plant a pond is late spring into early summer. The warmer water conditions at this time of year will give your plants the best chance of establishing. Planting in late autumn, winter or early spring should be avoided, as the water temperatures won’t be conducive to the establishment of new plants.

Whether your pond plant should be fully submerged depends on the type of pond plant. Oxygenating pond plants, such as hornwort, for instance, are often grown fully submerged with the help of weights, while other pond plants, like water lilies, grow floating on the pond surface with a rhizome anchoring it beneath the surface.

Yes, there can be too many plants in a pond. Too many plants can lead to issues like oxygen depletion, an imbalance of nutrients and too much debris floating around the pond. This, in turn, can result in an overproduction of algae.

Fully-submerged plants are often supplied in the form of bunches which can be weighed down to keep them fully submerged within the pond. Other pond plants, like marginals, which are grown at the shallow edges of the pond, typically make use of aquatic baskets. These are baskets with mesh sides, which are filled with aquatic compost/soil, planted up with the aquatic plant, then topped with a layer of aquatic gravel to help weigh it down. These baskets help more vigorous plants from spreading and also help keep plants nice and secure. Check out our guide to pond planting for more information.

No, pond plants don’t automatically always need to be planted in soil. Sometimes, they can be planted directly into gravel (or some other inert medium) in an aquatic basket. Heavier feeders, like water lilies, will benefit from being planted in a loamy, aquatic compost. Take care not to use regular compost as this won’t be heavy enough and may have chemicals in it that could leach out into the water.