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How to Grow a Specialty Garden

Planning a Water Garden

Until recently, water gardens were beyond the reach of many gardeners. Concrete -- expensive and difficult to install -- was the main material used in construction. Concrete also required special care to use and maintain. Most people had little choice but to call professionals for planning and installation, adding to the expense. A water garden was something one dreamed of but did not actually own.

Times have changed. With more modern pool lining materials -- PVC and fiberglass are currently the main ones -- material costs have dropped enormously and installation is easily carried out by anyone. You don't even have to know how to nail two boards together to be able to install a water garden.

Although water gardens can be placed just about anywhere, you may find the choice of sites limited depending on the type of plants you want to grow. If your goal is a simple reflecting pool, the choice of a location is up to you. But most people dream of a water garden brimming with water lilies and other aquatic plants.

This places a major limit on where the water garden can be placed, since water lilies require at least six hours of full sun per day to grow well (a few species will tolerate as few as four hours). Most other flowering aquatic plants also require abundant light; plants grown for their foliage alone are more tolerant. If you want to get the most out of your water garden, select a sunny location.

The amount of space available is also a factor. Even the tiniest yards have room for a small water garden (people have been known to raise goldfish and a single dwarf water lily in a tub on a balcony), but a truly balanced water garden with a variety of plants and animals takes a fair amount of space.

Pool depth is also a consideration. For a simple reflecting pool, you'll need only a few inches of water, but very shallow pools are subject to extreme temperature change, which is not conducive to living organisms such as plants and fish. A minimum depth of 18 inches for much of the pond's area is desirable. To overwinter plants and fish in cold climates, at least part of the pond should drop to three feet.

The shape of the pond will depend a great deal on the effect you wish to create. Square, rectangular, round, or oval ponds give a formal appearance to the yard, an effect heightened by using fountains. If you keep your yard neatly mowed, if shrubs and hedges are carefully trimmed, and other plantings are in formal beds, a geometric pond will suit it perfectly. If, on the other hand, your yard is composed of mixed borders and naturalistic plantings, a formal water garden would look out of place.

An irregularly shaped pond, perhaps with a border planting of bog plants to soften its appearance even further, would be more appropriate. Sometimes rectilinear or circular pools fit perfectly into matched settings. If you're unsure, try laying out the pool shape of your choice with a piece of garden hose, then look at it from every angle. It is far easier to spend a day or so testing different pond shapes and locations with a hose than to move an established water garden.

The topography of the site should also be considered. Ponds should not be placed in the lowest section of the yard: Any overflow could quickly turn the area into a bog. Make sure there is some possibility for drainage. If you plan to include a naturalistic cascade or waterfall, a yard with a somewhat abrupt slope is most fitting.

Finally, check with your municipality concerning zoning laws and fencing codes. Many cities and towns make no distinction between a water garden and a swimming pool. Security fencing may be required. For further security, you might want to wait until your children are past the toddler stage before you install a water garden.

Installing Your Own Pool

Many people these days choose to install their own garden pools. If that's your choice, there are two main alternatives: flexible liners and prefabricated pools. Both are inexpensive and can be installed by two people in a single weekend. Concrete pools are more expensive and require greater skills: It is generally best to contact a professional landscaper for planning and construction.

The pool surface itself must be perfectly even (one edge can be a bit lower to allow rainwater to drain away). If your yard is on a slope, you may have to dig further down at the higher end or even shore up the lower one to obtain the desired effect. Use a level throughout the installation process to make sure your pool remains on the level.

An even pool surface made the constuctioin of this pond a success.
©2006 Publications International, Ltd.
An even pool surface made the constuctioin of this pond a success.

Installing a flexible liner is the easiest and least expensive process for the nonspecialist. Be sure to use a liner specifically designed for water gardens, not just any sheet of plastic. Currently, PVC liners are most popular; dark shades will give the most natural effect. The thicker your liner is, the longer it will last and the more it will cost. Since light degrades plastic, look for liners with enhanced UV protection, especially if your pond is a shallow one. Rubber liners are the most durable but also the most costly.

To calculate the proper size for your liner, measure the width and length of the planned pool at the widest points, add twice the pool's depth and then tack on an extra foot for overlap. For example, a pool 10 feet long, 6 feet wide, and 2 feet deep would require a liner 15 feet long (10. + (2 ( 2.) + 1.) and 11 feet wide (6. + (2 ( 2.) + 1.).

Installing a Flexible Liner
  1. Outline the pool with a piece of garden hose. If your pool will be square or rectangular, use string staked carefully into place to do the outline. A framing square will be necessary to get a 90% angle at the corners.

  2. Dig out the pond to two inches more than the desired depth. Leave shelves about 6 to 18 inches (9 inches is average) deep in areas where you intend to place emergent plants such as cattails. Don't cut the edges perfectly perpendicular or they may collapse: A slight angle (about 20%) is best. As you dig, use a straight board with a level to make sure the pond's edge is perfectly level. If you'll be edging your pond in field stone, remove a further layer of sod from around its edges so the stones can be set evenly with the surrounding soil.

  3. Remove any stones, sticks, or other debris from the pool bottom and sides, then line the entire surface with two inches of damp sand. You may want to install a piece of landscape fabric over the sand for further protection against piercing, especially if you are using an inexpensive grade of liner.

  4. Spread the liner carefully over the excavation, folding it carefully at corners or curves. Mold the liner to the hole by pushing with your feet (remove your shoes first). Use stones to hold it in place.

  5. Slowly add water, smoothing out wrinkles as the pool fills.

  6. Cut away any excess liner, leaving six inches of liner overlapping at all points. Cover the overlap with soil or paving stones.
Installing a Prefabricated Liner
  1. Outline the pool's position with a piece of garden hose. Dig out the hole two inches wider and deeper than the required depth, making sure to take into account any built-in shelves. The final excavation should be a perfect image of the liner's form.

  2. Line the excavation with two inches of wet sand, checking as you go to make sure the base is level. Place the shell in the hole.

  3. Add water slowly, filling in the area around the shell with sand as you go. Add edging if desired.
In the next section, we'll discuss how to plant a water garden.