Water is a precious commodity for all forms of life in our hot, dry climate. You will undoubtedly spend hours watching dragonflies, fish, birds and other wildlife that reside in or visit the oasis of a water garden of any size.
Finding an ideal location for your pond should be your first consideration. It is possible to have a water garden in considerable (although not dense) shade, but leaves falling from nearby trees are a maintenance headache. Your largest selection of aquatic plants are those that grow in plenty of sun.
A pond can be constructed with a full scale, permanent concrete shell, reinforced with rebar and wire mesh, or it can be made with a more temporary, plastic liner that lasts from 10 to 20 years or more. These are most often decorated with rocks around the perimeter. A simpler alternative can be to use a galvanized metal stock tank (set directly on the ground or buried), or even a washtub, or a sealed clay pot.
After your reservoir is in place, the next thing to do is add water. If you are using city water, to give the chlorine time to evaporate, allow the water to sit for a minimum of 36 hours before adding plants or fish. If you have rainwater or water from a well, you may add fish immediately. Note that well water may be low in oxygen that is necessary for most organisms to survive. You can let well water sit for a day or you can oxygenate the water by spraying it into the pond as you add it.
You are now ready to add plants. For aesthetic and functional reasons, you should include a variety of plants that stand upright, trail or float, and a few that remain submerged under the surface (these are typically good for adding oxygen). Tall vegetation, such as horsetail, makes excellent perches for resplendent dragonflies. These insects provide captivating lessons on courtship and territorial behavior. Trailing and floating plants, like water lilies or coastal water hyssop, make good platforms where frogs, butterflies, and other insects can rest, sun and drink from the edge. Ideally, during the summer, vegetation should cover about 70 percent of the water's surface. Providing a diversity of plant forms with flowering periods that range throughout the growing season will make the most interesting and ecologically balanced arrangements.
Unfortunately, most aquatic plants currently available are not native to our area. While the majority of non-natives are harmless, many have the potential to escape or already have escaped cultivation to become noxious and aggressively invasive. Some of these are even illegal to possess such as water hyacinth and water lettuce. The relative scarcity of moisture that limits terrestrial plants does not affect aquatic plants. Thus, non-native wetland plants have a greater chance of becoming invasive. Moreover, they are able to spread easily and quickly through connecting water channels. Even though native aquatic plants are beautiful and diverse, finding them in nurseries is not yet easy. Only through customer interest will garden centers be compelled to offer them.
Fish are the key to a successful pond garden. If you have a healthy fish population, you will not have mosquito problems or stagnant water. The fish will breed until there are too many to be supported by the available resources; at this point a few may die until sustainable numbers are again reached. When you are ready to add fish, consider stocking with Mosquitofish, which are hardy, native fish. Ask a friend for a few to start you off or inquire at pond nurseries. Once you get them to your pond, set the container they are in into the water to allow the water temperatures to assimilate. Slowly add small amounts of pond water to the container to acclimate the fish to the new water chemistry. This process should take at least 15 minutes. When the water temperatures are the same in the container and in the pond, let the fish swim free.
It is not necessary to feed your Mosquitofish at all and doing so may lead to water quality problems. The fish will eat mosquito larvae and other insects as well as algae.
Filters are optional. A pond with a diverse and balanced system of plants and fish creates an ecologically harmonious pond habitat. If you use fish other than Mosquitofish, they may need feeding. In this case, it is recommended that you use one of various types of filters on the market. The water quality, with or without a filter, should stabilize over time as the pond becomes established. Periods of murkiness are to be expected. Consult pond experts if you are concerned.
Maintaining your pond involves only a few activities:
Fountains are not necessary for aeration if you have established plants and a balanced population of fish. Moving water, however, is attractive to people, birds and other animals. Use a calm trickle, stream, or water bell fountain. Too much splashing is detrimental to some plants and will repel some insects such as butterflies.
A flat rock sloping gently into the water can serve as a birdbath and a resting/rescue platform for animals. It can provide access to the water for animals such as turtles, frogs and insects. This should be protected from heavy splashing also. Be aware that these animals may be put in danger if you have pets that like to hunt.