Frogs and toads drink by absorbing moisture through their skin. They also need just the right amount of water to raise their young. They're often so hard-pressed for water that they choose unsafe places - such as swimming pools - as living quarters.
Building a pond can be an ideal way to attract toads, salamanders, and frogs to your backyard. Keep in mind that frogs hibernate every winter, and that it takes at least three years for tadpoles to develop into adult frogs. You will have to provide these amphibians with a permanent body of water - at least half a metre deep - if you want them to survive beyond their first summer.
- Check with your local bylaw inspector to see if there are any restrictions on building this type of pool in your area.
- Find a partially shaded spot in your backyard that gets no more than four hours of direct sunlight per day. Otherwise, the algae growth in your pond could get out of hand.
- Before you start digging, make sure the pond will be within reach of a garden hose. You'll need to add water during periods of low rainfall, and freshen up the water if it gets stagnant in late summer. It's also a good idea to build your pond close to a garden or unmown section of your lawn; this will draw plenty of bugs and keep amphibian occupants well fed.
- Excavate a hole at least 3 m x 3.5 m x 50 cm deep, giving one side a gradual slope.
- Remove any stones or sharp objects and line the bottom with sand to a depth of 5 cm.
- Cover the surface with a 45 mil EPDM rubberized pool liner, black in colour, and put a bit of soil on top. Weigh down the outer edges of the liner with flat stones and enough soil that vegetation will grow around the border.
- Fill the pond with water.
- Add aquatic plants and fish. Aquatic vegetation can be planted in pots before being submerged at varying depths in the pond. If your water is chlorinated, let it stand for 24 hours first.
- Plant grasses around the edge of your pond to attract insects for hungry amphibians.
- Place a small island of rocks about 1 m from the edge of the pond as a resting spot for frogs and dragonflies.
- Don't be disappointed if amphibians don’t take up residence in your backyard pond right away. Sometimes they're slow to expand their ranges.
- Never catch frogs or toads and relocate them to your pond. Amphibians have been known to travel over three kilometres to return to the pond where they grew up.
- For more ideas on building a backyard amphibian habitat, the Metro Toronto Zoo’s Guide to Restoration and Frog-Friendly Backyards is available online.
- Add to the pond water during dry spells. Freshen it up if it becomes stagnant in late summer.
- If you use a recirculating pump, clean the filter once a week.