Wildlife Ponds: Benefits and Design

Written by David S., Green Thumb Nursery contributor.

Quick answer: A wildlife pond is any contained water feature, from a simple birdbath to an in-ground pond, designed mainly for the creatures it serves rather than for fish. Water is scarce in Southern California, so even a small pond becomes an oasis where birds drink and bathe, bees and butterflies sip safely, dragonflies hunt mosquitoes, and native frogs and toads come to breed [1] [2].

Wildlife ponds vary in size, from lakes and large natural ponds to the tiny five-gallon oasis in our gardens. A straightforward example of a wildlife pond is a birdbath. It is nothing other than water set out for birds to use. In this article, we cover why wildlife ponds are so beneficial, what animals they attract, how to build one safely, which plants belong in them (and which to avoid), and how to keep mosquitoes from moving in.

What Is a Wildlife Pond?

A wildlife pond is a water feature whose first job is serving the surrounding biota, which in science means the living things of a region. That is what separates it from a koi pond or a decorative fountain, where the water is really there for us. Most backyard wildlife ponds are preformed containers designed to hold water for many years, such as galvanized tubs and rigid plastic pond liners, and they can be installed above ground or in the ground. The simplest ponds can be a hole in the ground with a flexible liner, and a five-gallon bucket can become a frog habitat simply by burying the bucket and placing stones around the rim. The National Wildlife Federation notes that even a barrel sunk into the ground is enough water for frogs to use [3].

From the human perspective, a wildlife pond should be aesthetically pleasing, functional and safe, and low maintenance. From the perspective of the surrounding biota, it should simply be a place where water is available consistently. The key ingredient is water. What we do from there is up to us.

Why Are Wildlife Ponds Beneficial?

Ponds are important because most animals need water to drink, and many also use it for feeding, bathing, breeding, regulating body heat, and cover [1]. In an environment where water is scarce, a wildlife pond becomes an oasis to the animals that visit your yard:

Songbirds drink and bathe in the shallow edges [1], and you can pair a pond with plants that attract hummingbirds year round
Bees and many other beneficial insects need a safe, shallow water source, especially in dry weather [2]
Butterflies gather moisture and nutrients from wet sand and mud at the pond edge [1]
Nearly all amphibians return to water to breed [3]
Dragonflies lay their eggs in ponds, and both the young and the adults eat other insects, including mosquitoes

As a species, humans take a lot from the natural world, and we give back very little. So, on the subject of tiny contributions, these small ponds are an easy way to give back to and support the smaller forms of life that share our yards. As the gardener, you decide and design the types of critters who benefit and come to your pond. The tools you use are plants, the size of the pond, and its location.

What Animals Live in Ponds?

A backyard wildlife pond in Southern California can attract a surprising range of visitors and residents:

Frogs and treefrogs. Our local Baja California treefrog (formerly grouped with the Pacific treefrog) is found throughout Southern California and breeds in quiet water between roughly November and July [4].
Toads. The western toad lays its eggs in still or barely moving water such as pools and ponds [5].
Dragonflies and damselflies. They spend most of their lives underwater as larvae and patrol the garden for flying insects as adults.
Birds. Everything from finches to hawks will stop at reliable water, and a pond pairs beautifully with a winter bird garden.
Lizards. Fence lizards and alligator lizards hunt the insects that water and fruit attract.
Mammals. Raccoons, possums, skunks, and in some neighborhoods even deer will visit for a drink. Be aware that raccoons are skilled fishers and occasionally prey on koi in backyard ponds [6], another reason a wildlife pond is happier without expensive fish.

If you want more of the helpful visitors, ponds work hand in hand with beneficial bugs and organic pest control, since many predatory insects need water just like the pests they eat.

How Big Should a Wildlife Pond Be?

Some beautiful wildlife ponds are tiny, and some range to a thousand gallons or more. Size does not matter nearly as much as matching the pond to the creatures you want to serve. If you do not mind deer roaming the yard, a large in-ground pond is perfect. If you want dragonflies and treefrogs, a small container pond does the job.

The considerations for sizing include the space you have, the creatures you want to attract, whether you have small children (more on safety below), and expense and maintenance. One factor people forget is weight. Water weighs 8.34 pounds per gallon [7], so even a 100-gallon pond holds roughly 834 pounds of water, and a 500-gallon pond is carrying well over 4,000 pounds. Small container ponds up to about 50 gallons are fine on a sturdy deck, but anything larger belongs on the ground or in it.

Wildlife pond type	Best for	Placement	Care notes
Birdbath	Songbirds, bees, butterflies	Anywhere, in sun or part shade	Refresh weekly and scrub regularly so it stays clean and mosquito-free
Buried bucket or barrel	Frogs, toads, dragonflies	Sunk into the ground, rim at soil level	Add a rock ramp so wildlife can climb out; one potted plant and a Bti dunk
Container pond (tub or rigid liner, roughly 20 to 50 gallons)	Dragonflies, birds, treefrogs	Patio or sturdy deck, remembering water weighs 8.34 pounds per gallon	Potted marginals plus a submerged oxygenator; Bti or a small pump
In-ground pond (100 gallons and up)	The full habitat, from pollinators to visiting mammals	On or in the ground only (100 gallons is roughly 834 pounds)	Thin the plants once or twice a year; mostly looks after itself

Wildlife pond options for Southern California yards, from simplest to most involved.

How to Build a Simple Wildlife Pond

You do not need a contractor for a wildlife pond. Here is the basic process we recommend:

Pick a spot with 5 to 6 hours of sun. Most pond plants and the wildlife that use them do best with at least five to six hours of sunlight a day [1]. Some afternoon shade is a plus in our hottest inland areas.
Choose your container or liner. A galvanized tub, a rigid preformed liner, or a hole with a flexible liner all work. Pond kits make this easy, and we carry them at our stores.
Give one side a gentle slope. A gradual “beach” lets birds bathe and lets small animals climb in and out safely. A drop of about 6 inches for every 3 horizontal feet is a good slope, with sand or small rocks for footing [1]. Containers with vertical sides need a ramp of stacked rocks or a piece of untreated wood, because steep smooth sides can trap and drown beetles, small mammals, and songbirds [2].
Vary the depth. Shallow shelves around the edge hold marginal plants and give songbirds a bathing spot, while a deeper middle zone stays cooler and gives pond life a refuge.
Add plants in pots. Potting your pond plants in containers of heavy soil keeps them where you put them and makes pond care much easier [1].
Let it find its balance. A planted pond largely takes care of itself. The plants help clean the water, and the water sustains the plants. Thinning the plants once or twice a year is usually the biggest chore.

If you plan to use the pond as a sitting area, you might enjoy the shade of a small tree or a pergola with a vining plant on it. Strawberries are another plant that does well around a pond. Lizards will eat the fruit and prey on the insects the fruit attracts. Surrounding the pond with native flowering plants multiplies the habitat value, since natives feed the local insects that pond visitors hunt.

How to Attract Dragonflies with a Dragonfly Pond

If you want to attract dragonflies to your yard, a pond is the way to do it, because dragonflies need water to complete their life cycle. They spend most of their lives underwater as nymphs, called naiads, for several months and in some species up to three years, then emerge to live as adults for only about six weeks [8].

A good dragonfly pond is sunny, has shallow planted edges, and includes emergent plants such as rushes, sedges, and grasses that stand up out of the water. Adults use the tall stems as perches, and the naiads climb them when it is time to emerge [1]. The Xerces Society publishes a free guide to building backyard ponds for dragonflies and damselflies if you want to go deeper [9].

Here is the honest trade-off: fish and dragonflies do not mix well. Fish eat the eggs and larvae of amphibians, dragonflies, and other aquatic species, so a fish-free pond supports far more breeding wildlife [1]. If mosquitoes are your worry, the dragonflies themselves help, since a benefit of a dragonfly pond is that dragonflies eat other insects, such as mosquitoes, and there are fish-free mosquito controls we cover below.

The Best Plants for a Wildlife Pond

Pond plants fall into three working categories [10]:

Submerged plants, also called oxygenators, grow entirely underwater and release oxygen into the water. Hornwort, also called coontail (Ceratophyllum demersum), is the classic example, and planting it is as simple as weighting the stems so they sink.
Floating and floating-leaf plants shade the water. Water lilies belong here, rooted in a pot at the bottom with leaves floating on the surface. They are not marginals, a common mix-up.
Marginal plants sit on the shallow shelves at the pond edge, living with wet feet. Iris, sedges, and rushes are favorites, and they double as dragonfly perches.

A few cautions from our own experience and the invasive plant lists. Skip water hyacinth and water lettuce entirely. Water hyacinth is rated High on the California Invasive Plant Council inventory [11], and water lettuce carries a Moderate rating with an Alert flag because its floating mats can expand rapidly and starve the water of oxygen [12]. Duckweed reproduces so prolifically it can cover an entire pond surface and block sunlight [13], so think twice in a small pond. And horsetail, while striking, spreads vigorously by underground rhizomes and is very hard to remove once established [14], so keep it confined to a pot.

For a full walk-through of our favorite choices, including what to avoid in California, see our guide to the best pond plants for small ponds.

How to Keep Mosquitoes Out of a Wildlife Pond

This is the number one question we hear about ponds, and the good news is that a healthy wildlife pond is not a mosquito factory if you follow a few rules:

Keep the water moving. Moving water discourages mosquitoes from laying eggs [1], and many birds are actually drawn to the sound of a small fountain or dripper.
Use Bti mosquito dunks in still water. Bti is a naturally occurring bacterium that kills mosquito larvae but does not affect people, pets, wildlife, or plants, according to the University of California’s statewide integrated pest management program [15]. Follow the label.
Consider free mosquitofish for larger contained ponds. Mosquitofish (Gambusia affinis) are not guppies, though they are small members of the same family [17], and they eat mosquito larvae. Many Southern California vector control districts, including the Greater Los Angeles County district, provide mosquitofish free to residents for backyard ponds and fountains [16]. One important rule: it is against California Department of Fish and Wildlife regulations to release mosquitofish into creeks, streams, or any natural waterway [16]. Remember the trade-off above, though. Any fish, including mosquitofish, will also eat dragonfly and amphibian young, so the most wildlife-rich ponds rely on Bti and moving water instead.
Refresh small water features weekly. UC’s pest management guidelines recommend changing the water in birdbaths, pet dishes, and similar containers every week so mosquito larvae never mature [15].

What about goldfish? Goldfish are coldwater fish, and since warm water holds less dissolved oxygen than cold water [18], a small, sun-warmed pond is a stressful home for them. The UC Master Gardeners also caution that large koi and goldfish damage water plants and attract raccoons [19], and fish of any kind will quickly eat the tadpoles you were hoping to raise [3]. For a true wildlife pond, we suggest leaving the fish out.

Wildlife Pond Safety and Maintenance

If you have small children, treat any pond with the same respect you would a pool. Children are naturally curious, and the Consumer Product Safety Commission has documented child drownings in landscape ponds and fountains, not just swimming pools [20]. Supervision is the real answer, and the National Wildlife Federation suggests adding a fence if small children play near your pond [21]. Placing the pond where young kids cannot access it unsupervised is critical.

Beyond that, most wildlife ponds require very little maintenance. The key is balancing the water with the plant life so the pond achieves a biological balance. A reduction in plant populations once or twice per year is usually all it takes. Birdbaths are the one exception that need regular attention: the Audubon Society recommends refilling every other day and scrubbing with nine parts water to one part vinegar, skipping soaps and cleansers, because dirty baths can spread diseases such as salmonellosis among birds [22].

There are almost no limits to what you can do with a small pond and landscape design. For more inspiration, please stop by any of our five Southern California Green Thumb Nursery locations and browse the pond kits we carry. While you are here, investigate the many plants that are suitable for ponds or around ponds. We even have pergola kits. Our plant experts are here to help you too. If you need recommendations about plants, ponds, or pond products, they are happy to help.

Wildlife Pond FAQs

How do you attract dragonflies to your yard?

Add a sunny pond with shallow edges and emergent plants such as rushes and sedges for perching, and skip the fish, which eat dragonfly eggs and larvae [1]. Dragonflies spend months to years underwater as naiads before emerging, so a permanent water source is the single best attractant [8].

Do ponds attract mosquitoes?

Still, stagnant water can breed mosquitoes, but a well-run wildlife pond does not have to. Keep the water moving with a small pump, use Bti mosquito dunks, which UC’s pest management program notes kill larvae without harming people, animals, or plants, and refresh birdbaths weekly [15]. Dragonflies and other pond predators eat mosquitoes too.

Where can you get free mosquitofish in Southern California?

Most Southern California mosquito and vector control districts, including the Greater Los Angeles County Vector Control District, give mosquitofish away free to residents for contained backyard ponds and fountains [16]. Contact your local district, and never release the fish into natural waterways, which is against California Department of Fish and Wildlife regulations [16].

How deep should a wildlife pond be?

Varied depth beats one deep hole. Give the pond a shallow sloping beach of a few inches for birds and small animals, shelves around 6 to 12 inches deep for marginal plants, and a deeper central zone that stays cool and sheltered [1]. A good slope is about 6 inches of drop for every 3 horizontal feet [1].

Can a wildlife pond work without a pump?

Yes. A well-planted pond with submerged oxygenators, floating leaves, and marginals can reach a natural balance where plants keep the water clean without any equipment. The trade-off is mosquito control, so a pump-free pond should include Bti dunks, since still water is where mosquitoes lay eggs [15].

Do wildlife ponds attract rats?

Any reliable water source can draw thirsty animals, and in a dry year that occasionally includes rodents. Good housekeeping is the answer: UC pest management guidelines note that removing food sources such as fallen fruit, garbage, and accessible pet food is the foundation of keeping rats away [23]. A tidy pond area gives rats no reason to linger, and the owls, hawks, and other predators a healthy habitat attracts help keep rodents in check.

Is a wildlife pond safe with small children?

Only with precautions. Even shallow landscape ponds and fountains have been involved in child drownings [20]. Supervise children near water, consider a fence around the pond [21], or stick to a raised container pond or birdbath until the kids are older.

What is the easiest wildlife pond for a beginner?

A container pond or a buried bucket. A five-gallon bucket sunk into the ground with stones around the rim makes a genuine frog habitat, and even a barrel sunk in the ground will serve breeding amphibians [3]. Add a ramp of rocks so wildlife can climb out, one potted marginal plant, and a Bti dunk, and you have a working wildlife pond for under an hour of effort.

Sources

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