Constructing your pond
Most pond lining material is made from either polythene or butyl rubber, but some ponds are clay or concrete-lined. You can buy pre-formed plastic liners from garden centres, but, for wildlife, many of these are more trouble than they are worth: they are difficult to fit and level and tend to be very steep-sided. They are also very expensive for their size.
Having dug the basic hole for your pond, line it with a smooth layer of newspapers, sand or old carpet to prevent the plastic liner being punctured. Lay the liner in the hole, but do not stretch it too tight. You must allow room for it to expand. Make sure the liner is large enough to overlap the edges, and weigh it down. These edges can be covered by turf to give a pleasing appearance and to protect them from sunlight. Add a further layer of sand or soil over the liner once you have laid it to prevent it being broken down by sunlight.
Fill your pond with water, and allow it to stand for a couple of days before stocking it to allow any chlorine in the water to dissipate.
Stocking the pond
You may be surprised just how rapidly insects, frogs and plants colonise your new pond. A bucket of water from an established pond will help to boost the wildlife of your own more quickly. At GardenAdvice.co.uk we have two designers/advisors specialising in wildlife ponds to assist you with any planting questions or advice you might need.
It is best to have a mixture of submerged plants, floating plants and emergent plants, those that are rooted in water but whose foliage extends into the air. Native plants to look out for are:
Submerged Water-milfoil Myriophyllum, curled pondweed Potamogeton crispus, hornwort Ceratophyllum, water starwort Callitriche.
Floating White water-lily Nymphaea alba, ivy-leaved duckweed Lemna trisulca.
Emergent Yellow iris Iris pseudacorus, meadowsweet Filipendula ulmaria, purple loosestrife Lythrum salicria, rushes Juncus, sedges Carex, greater spearwort Ranunculus lingua, water mint Mentha aquatica, water forget-me-not Mysootis scorpidides.
Some plants, especially non-native ones, can take over a pond and are best avoided. These include New Zealand stonecrop Crassula helmsii and water fern Azolla filiculoides.
Pond management
In the early years, blanket weed can cover ponds in warm weather. This can be pulled out carefully, but once the pond has settled down blanket weed will usually be kept in check by the pond animals. Other plants can also threaten to take over, and again these are best cleared out. Do not remove more than one-third of any species in a year because the pond creatures need them. You will cause least disturbance to most pond animals if you only remove the plants in the winter. Generally, pond management should take place between October and January.
Keep the water level topped up, but do not worry too much if it drops a bit during the summer. Most pond plants can cope with this.
Try to keep a hole open in the winter ice so that birds can wash and drink. A tub of hot water placed on the ice will melt a hole.
