Creating a pond

The January 2014 meeting of the Garden Club of PEI featured Chris Prouse, who has many years of experience creating his own ponds and other water features in his own back yard.  He says he has built 10 ponds, and nine were mistakes!

There are many types of ponds:

• natural
• cement
• pre-formed
• liner (Chris says this is the best choice)
• container (Chris says old bathtubs or discarded satellite dishes make a great container)

Site selection

Choose a site where you can dig at least 2 feet deep.  In a shady site, the pool will develop fewer algae problems.  You want to avoid being too close too close to overhanging trees, because falling leaves will have to be cleared out.  Decide if you want your pond to be the centrepiece of your backyard, or if you want it to be a hidden surprise.

Building the pond

The best site has a backslope.  Dig a hole at least 2 feet deep in front of the slope, and put a berm in front.  The pond should have two levels.  One level is about 6 inches deep, which will be for plants such as rushes.  The second area should hold at least 18 inches of water.  Use a sheet of styrofoam to stabilize the slope. Cover the bottom of the hole with old carpeting.  That will cushion the liner and protect it from punctures.  Buy a good quality pond liner that is at least 1/3 larger than the size of the hole, to allow for the depth and the overhang.  The liner must be one piece, to avoid leaks.  

An 18-inch pond will allow plants to overwinter, but will not support fish over winter.  Fish in a shallow pond must be brought inside for the winter.  Chris says his biggest mistake in building ponds was to not make them deep enough.  He says 18 inches is good, and 2 feet deep is better.  Other mistakes include a cement bottom that cracked, buying a cheap liner, and creating a pond that did not have a level bottom.  The bottom of the pond must be perfectly level, or the water will not be level.  

A submersible pump keeps the water flowing.  One option is to use a UV light to kill bacteria, and to build a filter box to keep the water clear.  You need an outside electricity source to plug in the pump.  Make sure the electrical source has a ground fault interrupter.  If you bury the electrical lines, feed them through a PVC pipe first to protect the wires from damage. Bury wires at least 6 inches deep.

Access

People, especially kids, are naturally drawn to ponds.  Make it easy to get close by building a small platform that slightly overhangs the edge of the pond. 

Plants

Submerged plants:  Waterlilies taken from the Agriculture Canada lily pond are very hardy. He contains the plant roots in nylon stockings, which will stretch to accommodate root growth.   

Floaters:  duckweed, water hyacinth

Wetland plants:  arrowhead plant, bull rushes, native grasses, elephant ear (taro), yellow flag iris.  

Around the margin of the pond:  Willow, siberian iris, lupins

Wildlife

Chris does not find that mosquitoes breed in his 18-inch deep pond, but they do appear in his shallower, smaller container water features.  The pond attracts birds, pond insects such as dragonflies, amphibians such as newts and salamanders and frogs.  The salamanders appear in the spring, lay eggs which hatch into a form that has external gills and walks on the bottom of the pond.  The mature salamanders disappear into the woods after breeding season.  Frogs appear for a short time, but do not lay eggs in the pond.  Racoons visit too.  Chris suggests stocking the pond with feeder goldfish, which grow quickly and are not expensive.  

Maintenance
Chris says in the 17 years of owning a pond, he has had to drain it only three times.  He drained it to tackle his waterlily plants, which were growing so profusely they had to be divided.  He says that the pond's water will eventually settle into a natural balance with little algae forming.  He does not use chemicals.

Container ponds
An old bathtub can become a bog garden or a water pond.  It can be planted with arrowhead and water plantain, which are free to dig up.