Water Garden Design

Choose a site, which receives four to six hours of direct sunlight, every day, and one that is close to an area in which you can sit and enjoy the water garden. Avoid drainage into the pond. Scale the size to fit the location but make it as large an area as possible.


LINER: a pond, two feet in depth, is ideal for zone 6. In zone 5 or less, dig a three-foot hole around a waterfall for increased winter protection for any fish you may wish to include in the pond. Make shelves to support edge rocks only, or for pre-determined edge planting. Sides should be steep (10 to 20 degree angle). Level the edges. Water seeks its own level.  Clean excavation of stone and other projectiles. Line bottom with three inches of sand and damp pat the hole in the sides. Lay a fabric liner clothe over the bottom and sides. Lay pre-cut P.V.C. or EPDM liner loosely into the hole.  (Calculate liner size by measuring the maximum length and width, adding twice the maximum depth and at least two feet for edges). Fill with water and tuck the folds as the excavation fills. Edge with stones or plants and trim excess material.

PREFORMED: For in-ground ponds, dig a hole to fit the preformed pond, whether it is fiberglass or rigid plastic. Level the bottom and line with sand. Insert and fill with water. Back fill with sandy soil as it settles.  Edge with your choice of materials.

For above ground, any rigid watertight container is ideal fibreglass, wood frame supported plastic, wine barrels, etc. Place on decks, balconies or difficult to dig soils. Remember water weight 1 kg. /L.

Pumps, Water Falls and Fountains

Build rock waterfalls from the edge up. Use plastic liners to underlay and contain any excess run-off. Support rocks with rigid pieces of styrofoam.

Pumps are rated by gallons per hour or litres per minute. Choose one to fit the height and flow you need. A pump rated at 80 gph is minimum for a small water trickle or fountain. One rated at 1200 gph (with a one-inch discharge) is for larger flows at greater heights. Flow rate varies as height and number of connection splits.  A Ground Fault Interrupter (GFI) power source must be within six to 12 inches of the pump.

Planting and Maintenance

Plants: there are three types of water garden plants.

  • Underwater: Oxygenators are very important for water quality. They compete successfully with algae for nutrients and are a major contributor to the clearing of the water.
  • Floating Plants: Water lily pads, Floating Water Hyacinth, Floating Heart, etc. shade and cool the water, thereby contributing to algae control. Algae requires dissolved nutrients and sunlight to thrive, therefore about 60 per cent water coverage is ideal.
  • Marginal: Edge planting and moisture-loving perennials not only create a pleasing appearance; they also utilize soluble nutrients and thus, help starve off algae.

Fish: Add fish two weeks after plants have been established. Test water quality.  Introduce inexpensive gold fish first. Under stock the pond until a balance is found.  Do not feed or over-feed the fish as there is enough larvae, dead algae and vegetation to nurture them. Fish tend to over eat and contribute to an ammonia imbalance. Fish waste breaks down by beneficial bacteria into usable nutrients that the plants consume.

Algae: plants and fish in a well-balanced pond best control algae.  Algaecides are a temporary control.

Winter: remove fallen leaves and decaying plant material. Leave fish and hardy plants in ponds that are two feet deep. Marginal hardy plants freeze in winter and revive in the spring.  Tropical plants require tropical conditions indoors to survive.  Cover ponds that are less than two feet deep and install an oxygen bubbler for the fish. Empty shallow ponds and above ground containers.

Spring: clean out major bottom debris. Bacteria will take care of the rest. Do not replace old water. It is already conditioned. When plants grow, the pond will balance itself, e.g. Water lilies. Spring feed fish when water is above 10 o C.

Sit back and enjoy

If someone says that water gardens are difficult to build and hard to maintain, then sit back and watch them weed and fertilize their gardens.

Water Garden Design