Principles of swimming ponds
Popular because of the Kings Cross swimming pond these have been featured in magazines recently
Swimming ponds in a garden setting:
- Use plants to keep the water clear
- Have at least 50% of your total water area as a planted zone
- Create bacterial conditions in the planting area among the plant roots to help cleanse the water. Useful micro organisms like water fleas also thrive.
- Do not use chemicals or chlorine
- Brings the swimmer closer to nature
- Encourages many species of wildlife creature to colonise this new garden habitat.
- Exclude fish and ducks from your swimming pond as both create high levels of nutrient and bring a risk of unhealthy impurities
- Allow ‘swimming pools’ to fit into the garden rather than looking like a separate, functional item in the garden
- Can be a safety hazard for children and should be monitored carefully. Deep water in the swimming area is hazardous for the young who are instinctively drawn to water.
- On the upside children can see nature close up if they are supervised.
Constructing a swimming pond
- Usually built by specialist swimming pond contractors.
- Create a deep area for swimming (at least 2.4m = 8ft deep) with one liner
- Create a separate area for the plants of a shallower depth that has its own liner – called regeneration zone.
- Separate the 2 areas by a barrier that allows the water to flow across the top of the barrier between the 2 areas but not to allow materials like soil to spill from the planting zone into the swimming zone
- Contain a circulatory pump system to keep the water on the move around the system which could include a biological filter unit.
Planting a swimming pond
A range of aquatic plants are densely planted – submerged oxygenators, waterlilies, floating plants, shallow marginals, deep marginals, bog and waterside species.
- It is good to use indigenous Native plants as they are most adapted to our climates and grow vigorously but ornamental varieties can also be included.
- These will increase the range of colour and flower type and extend the season of interest and the period of active nutrient usage in the regeneration zone.
- Aim for at least 9 plants per m2 of planting area.
The shelf plants favoured for a swimming pond are:
- British Native – tall and structural – Cyperus longus, Iris pseudacorus (Yellow Flag Iris), Butomus umbellatus, Alisma plantago-aquatica, Lythrum salicaria, Caltha palustris, Carex riparia and Schoenoplectus lacustris
- Non Native plants – other Iris – pseudacorus, versicolor and louisiana Black Gamecock, Pontederia cordata, Anemopsis californica, Typha lugdunensis
- Rafting plants that grow out across the water surface – Myosotis scorpioides (blue or white), Veronica beccabunga, Mentha aquatica, Oenanthe javanica Flamingo or Menyanthes trifoliata
- Deep water plants to give surface cover and put shade across the pond surface and submerged plant growth are also essential:
- Oxygenators – Ceratophyllum demersum, Myriophyllum spicatum, Potamogeton crispus
- Waterlilies (any colour) and Aponogeton distachyos.
British Native structural plants suggested:
Non Native structural plants: