Container Water Garden

A container water garden is a small aboveground pond that can provide a permanent source of water for birds, chipmunks, and squirrels. Even tree frogs may utilize a container that has 18" - 24" sides to lay their eggs among plants floating on the water's surface. To enable small birds to drink from the container, either keep the water level close to the rim or provide a branch on which they can land and perch.

Container: Most types of non-porous container will do. Select the appropriate size in ratio with the size of plants. Avoid containers that previously held wine or whiskey, as the wood can hold bacteria. Use a liner if you desire that style of container.

Plant Selection: Strive for a balanced selection of water plants—e.g., floating leaf aquatics, oxygenating grasses, bog, and marginal water plant species. Four to five plants can fill a pot that has a 16" diameter and is about 12" deep. For a focal point, a larger plant can also work.

Oxygenating grasses help maintain the proper pH balance of the pot's water. Examples include: anacharis (Egeria densa), fanwort (Cabomba caroliniana), feather grass, and blood grass.
Bog plants grow naturally in shallow waters so they can be propped up on rocks or upside down in a small pot so the larger pot's water just barely covers the roots and soil they are in.
Floaters, such as water lettuce, reduce algae. Please note that water hyacinths are invasive if released in natural watersheds.
Marginal plants sit at the bottom of the pot. In nature they are on the "margins" of bodies of water, such as marshes and swamps. Examples include horsetail and yellow iris (Iris pseudacorus).

Soil:

Aquatic soil is easiest to work with and is usually made up of kiln-fired clay particles. It holds nutrients well and provides a strong base for anchoring plants.
Clay soil is one of the best options for aquatic plants, as it holds nutrients and anchors all plants very well. However, too heavy a concentration of a clay can reduce healthy root growth.
Gravel can be used for short plants, but has no nutrients. Gravel is useful to help hold plants in place.

Note: Do not use potting soil—it has too many organics and will just float. Use fertilizer sparingly; water and soil provide plants with the nutrients they need.

Water and Pot Maintenance:

There are several options for mosquito deterrents:

Bubblers or fountains can be either solar- or electric-sourced and will eliminate mosquitoes by keeping water from becoming stagnant.
Mosquito dunks can be purchased at your local garden center. They consist of Bacillis thuringensis, a bacterium that is toxic to mosquitoes but is safe for wildlife and people. To use, simply float mosquito dunks in the pot.
Small gold and mosquito fish can also be used in pond pots. For example, Gambusia, a type of fish, actually eat mosquito larvae—however, they should not be released into natural watersheds, as they are invasive.

Prevent algae by covering two-thirds of the water's surface using water lilies, floaters, or other plants that shade the surface of the water. Reducing the amount of sunlight that penetrates the pot keeps the water cooler and starves the algae for sunlight. Drain and clean the pot, then pare down overgrown plants when two inches of decomposed matter builds on the bottom of the pond pot.