Water gardening made easy: an in-depth look

Flower & Garden Magazine, July, 2002

8. In all cases, add a layer of gravel to the top of the pot. This will help keep the soil from floating out and prevent fish from digging in the soil.

9. Slowly place the pots in the pool to keep soil from floating out. Place pots on bricks to get the desired height.

10. Floating species can be placed directly into the pond with no other care needed.

Plants should cover 50 to 70 percent of the water surface. Native plants usually do not need fertilizer, but for some exotic water lilies, limited fertilizing once yearly may be required. Check with your nursery for care of plants and how deep to place potted plants. Be aware that over-fertilizing may cause unwanted algae blooms that can rob the water of oxygen.

* ADD FISH & SCAVENGERS

Consider stocking your backyard pond with native fish. They are fun to watch and help keep the pond free of unwanted insects. Most small ponds will warm up quickly in the summer, so be sure to stock with fish that can tolerate elevated temperatures.

You'll also need scavengers, such as aquatic snails and tadpoles, to help control algae. In cold climates, a heater may be necessary for fish to survive the winter. However, this uses a significant amount of electricity and, in most cases, probably is not justified. A better option may be to set up an indoor aquarium in which to over-winter fish and plants.

* MAINTENANCE

Algae are a common problem in many newly established ponds. The water often becomes an unsightly green after a few days. While your first instinct is to drain the pond and start over, this only prolongs the problem. Once a pond is "balanced," algae usually are kept at an acceptable level. A balanced pond is one in which the nutrients are at the appropriate level for the plants present. Excess nutrients and light are needed for algae. Reducing the nutrients and decreasing the amount of light entering the water will help reduce algae. Floating plants, or those with broad leaves, such as water lilies, will help reduce the amount of light available for algae and compete for available nutrients. Scavengers, such as snails, will help clean up wastes from the bottom of the pond.

Pond filters can help reduce algae but require maintenance, as filters need to be cleaned frequently if algae are a problem. Chemicals can also be used to control algae, but use cautiously, as they can be toxic to other plants and aquatic life. The need for algaecides should decrease as plants become established.

Excessive plant growth, especially of free-floating plants, may be a problem. Periodically skim off excess growth of duckweed, water lettuce and other floating plants. Monthly, prune dying plant material. In the spring, clean out some of the decaying plant material that has accumulated in the bottom of the pond. Remember: a natural pond is not a swimming pool, and too much cleaning can do more harm than good.

* SAFETY

Locate the backyard pond where it is unlikely to attract unattended children. Check local safety ordinances to determine if a fence is required for the specific depth and size of your pond, and check local building ordinances for depth and safety restrictions and permits. Equip outdoor outlets with a ground-fault circuit interrupter. Unplug the pump before cleaning the filter.