How to Be Plant Wise & pick the right plants for your garden pond

Invasive species

An invasive species is ‘any non-native animal or plant that has the ability to spread, causing damage to the environment, our economy, human health and the way we live’. Check if a species is native to your region here. Invasive species can cause damage in different ways including, out-competing local species, introducing diseases and physically altering local ecosystems. Once established, invasive species can be very difficult to control and it may be impossible to reverse damage caused to the environment. To reduce the threat of invasive species, some species cannot be sold in the United Kingdom as they may pose a risk to native environments. Since most plant species that are sold for ponds have to survive all year in native conditions, they may be able to survive in other environments outside of the garden pond. Some plants sold for aquariums may have the ability to tolerate local conditions, so we do not recommend using aquarium plants in outdoor ponds. Below is a list of species, some of which have historically been sold for ponds or aquariums, but are now considered invasive and their sale is not permitted:

• American Skunk Cabbage (Lysichiton americanus)
• Australian Swamp Stonecrop/New Zealand Pigmyweed (Crassula helmsii)
• Cabomba (Cabomba caroliniana)
• Canadian Waterweed (Elodea canadensis)
• Chilian Rhubarb (Gunnera tinctoria)
• Curly waterweed (Lagarosiphon major)
• Floating Pennywort (Hydrocotyle ranunculoides)
• Giant Salvinia (Salvinia molesta)
• Nuttall’s Waterweed (Elodea nuttallii)
• Parrot’s Feather (Myriophyllum aquaticum)
• Senegal tea plant (Gymnocoronis spilanthoides)
• Water Fern/Fairy Moss (Azolla filiculoides)
• Water Hyacinth (Eichhornia crassipes)
• Water Primrose (Ludwigia grandiflora)

More information on these species, including helpful identification guides, can be found at here. If you purchase any of these plants by accident, it is best to return it to the place of sale. If this is not possible, invasive aquatic plants should be disposed of in the most appropriate way, which may include composting, burning or burying plant material. See the Be Plant Wise campaign for more details. If in doubt on correct methods of disposal, email the GB Non-Native Species Secretariat using nnss@apha.gov.uk.

Good practice

There are three simple steps that all those involved with pond plants can take to easily and effectively reduce the risks posed by invasive pond plants.

Choose the right plants for your garden, pond and water features

• Ensure that you only buy plants which are suitable for your set-up and are not considered invasive. A good way to do this is to choose native species, although you must not take any plants from the wild since this may damage the environment and is illegal unless you have the landowner’s permission and the species can be taken.
• Be careful when sharing garden plants because you may accidently pass on invasive species or plant diseases. It is illegal to share and sell some species, so always check that you have correctly identified your plants.

Keep your plants in your garden, don’t plant them or allow them to grow in the wild

• Let local native plants flourish by not introducing or disposing of any plants into wild habitats. This is also true for species which may be native in other areas of the country. Position new plants away from the edge of your garden so they cannot spread into the wild. Always regularly deadhead seed heads/pods of invasive species and dispose of them carefully. If going to other gardens or volunteering at a different location, always wash your tools and boots to prevent the spread of any unwanted plant material.

Dispose of your unwanted plants, roots, weeds, seeds and seed heads responsibly

• Make sure that nothing from your aquarium or pond gets into wild habitats: you could be breaking the law and cause irreversible environmental impacts if it does. Some invasive species cannot be composted (e.g. Crassula helmsii), so check before putting them in your garden heap. Always make sure that any compost has been broken down properly before it is used again in the garden. In addition, some invasive species cannot be put in your council garden waste, so always check before putting them in the waste bin. Burning may be the only effective option for some species, but this should be done safely and in appropriate areas.

There are several other tips that you can follow when specifically dealing with aquatic plants:

• When buying a new plant, remove the surface layer of compost and wash the plant in a bucket to remove any seeds or unwanted plant fragments before positioning it in your pond.
• Use this and any other wastewater from your pond or aquarium on your lawn or to water plants in your garden, away from water bodies (or drains that flow into them) as it could contain fragments of invasive plants.
• If your pond is near a wetland or water body, avoid using any plants which are not locally native and if any invasive plants appear, remove them before they spread into the wild.
• Use unwanted aquatic plants in your garden as mulch, keeping this away from water bodies or drains.
• Protect your pond life by leaving any plants you have removed on the edge of the pond to drain for a few hours to allow any wildlife to return to the water before disposing of them.
• Pond animals and fish must never be released into the wild: it is illegal, they may not survive and if they do, they could harm native wildlife.