All round the world frogs are in serious trouble and loss of clean habitats is one reason why. We can help them survive by building a frog pond and it doesn't need to be big.

Best location

The best spot for a frog pond is somewhere partly shaded. Sun is needed to encourage the algae which feed the tadpoles but in full sun the water can become too warm. On the other hand, in too much shade there won't be enough light for plants.

Don't place the pond directly under deciduous trees or plants with poisonous leaves or berries as these will choke and pollute the pond. Remember, too, that frogs can be noisy at night so position the pond as far from yours and your neighbour's bedroom windows as possible.

Construction

You can make the pond any size you like but the depth should be between 40 and 80cm. Stepped sides let you grow plants which like different depths of water.

Remove all sharp or protruding objects from the hole then line with sand and plastic sheeting. Polythene rolls which are cheap will do, but won't last very long. Long-life pond liners cost more, but are better value. Line the edge of the pond with rocks or logs for a natural appearance or bricks or payers if you'd prefer a more formal look.

Clean water

Fill with water and either let stand for a week to allow chemicals in tap water to dissipate or add water purifier (from aquariums).

Pond plants

It's best to use mostly native plants in and around the pond because they are the ones which frogs have evolved to live with. But you can also use showy exotics such as water irises, river lilies, lotus and waterlilies.

You'll need a mixture of:

• underwater oxygenators such as myriophyllum
  plants which float on the surface such as waterlilies
  plants which rise out of the water such as club rush and river bamboo

If you can create areas of boggy ground around the edge of the pond, they will become additional habitats for marsh plants such as the grassy Restio, and for frogs, too. You can buy suitable aquatic plants from water garden specialists (see Yellow Pages under 'Fountains Statuary & / or Sundials') and some aquariums.

Fish

Without fish, the pond will breed mosquitoes but, whatever you do, don't add goldfish or mosquito fish because they'll eat the tadpoles, too. Instead use native fish such as rainbow fish, Pacific blue eyes, Australian smelt or cloud minnows. Fish which are naturally found in your area are the best choices so check with a good local aquarium.

Frogs

Frogs and tadpoles are protected and in many parts of Australia it is illegal to collect them. But frogs have a way of finding good homes regardless!

Tips

• Dense growth of rushes and iris on the edges allow frogs breeding sites.
  Edging rocks hide pond liner and allow frogs in and out.
  Waterlilies need a square metre of surface and sun.
  For best appearance, keep two thirds of the water surface clear of plants.
  Protect the pond from small children and the children from the pond! Lay a piece of heavy duty mesh just below the surface on bricks or rocks to make it safer.
  Discover the frog species in your area. Use field guides or contact local frog groups for help.

Plant suggestions

• Eriostemon
  Lythrum salicaria
  Iris
  Brachycome
  Callistemon
  Schoenoplectus
  Viola hederacea
  Kunzea ambigua
  Restio tetraphyllus
  Waterlilies
  Nardoo
  Caltha palustris
  Impatiens

How you can protect frogs

• Keep cats in at night.
  Create other frog refuges - rock piles, old logs and shrubby areas.
  Avoid fish which eat tadpoles, such as mosquito fish, goldfish and carp. Good choices include Pacific blue-eye, fly-speckled hardyhead and Australian smelt.
  Add a low-hung garden light to attract insects for frogs to eat.
  Reduce your use of pesticides and herbicides, especially near ponds. Weed by hand if possible.
  Use organic fertilisers such as manures and compost. Chemicals may burn frogs' sensitive skin.