Gardening for Wildlife

Build a pond

Related Terms: water, pond, insects, amphibians, frogs, toads

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 pick unsafe places like 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 need to hibernate every winter, and it takes at least three years for tadpoles to develop into adult frogs. So, you'll have to provide them with a permanent body of water - with at least one section 2 m deep - if you want these amphibians to survive beyond their first summer.

how to|upkeep

How to

• First check with your local by-laws inspector to see that there aren't any restrictions on building this type of pool in your area.
• Find a partially shaded (not deep shade) spot in your backyard that gets no more than four hours of direct sunlight a 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 or 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, which will draw plenty of bugs and keep amphibian occupants well fed.
• Excavate a hole at least 3 m x 3.5 m x 0.5 m deep, giving at least one side a gradual slope. (For overwintering frogs it must be at least 2 m deep in spots or you will need to install a pond aerator to keep it from completely freezing in winter.)
• 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 little soil on top. Weigh down the outer edges of the liner with flat stones and enough soil that vegetation will grow around the border.
• If using preformed ponds, which often have steep sides, add rocks or logs to allow frogs and toads to climb out of the pond.
• Fill the pond with water. If your water is chlorinated, let it stand for a week before proceeding.
• Add aquatic plants. Aquatic vegetation can be planted in pots, then submerged at varying depths in the pond.
• 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 more than three kilometres to return to the pond where they grew up.
• If the safety of small children is a concern, you may want to install a fence around the pond.

Upkeep

• Top up the pond water during dry spells. Freshen the water if it becomes stagnant in late summer. It is best to let the water sit for a week before adding it to your pond to allow the chlorine to evaporate. Alternatively you could use water collected in a rain barrel.
• Remove fallen leaves in the spring and fall to prevent fouling of your pond.
• If you use a recirculating pump, remember to clean the filter once a week. (These pumps, which create the sound of running water, will attract birds to your pond.)