A container water garden is a great way to create a miniature oasis for wildlife and to bring the sound of moving water to your landscape without needing the space, time, or energy required for an in-ground water feature. Containerized water gardens are easy to make and maintain. They are miniature water gardens that host plants, birds, frogs, and insects. You can even place a few small fish in them to add another element of interest. This article offers inspiring ideas for container water gardens, tips for maintaining them, and shares simple instructions for DIYing your own.
What is a container water garden?
A container water garden is basically a mini water garden. It’s a small pond that’s contained in a decorative vessel. Container gardeners know how growing in pots simplifies the gardening process and reduces the maintenance required of the gardener (no weeds!). It’s the same with water gardens in pots. They’re low maintenance and easy to set up. Within a couple of weeks, your mini water garden will become an established habitat for water-loving creatures, and you’ll come to look forward to spending evenings sipping wine with the sound of moving water from your mini-pond in the background.
A container water garden can be simple or complex. It can be large or small. There are only a few essential elements needed: a watertight container, a few aquatic plants, water, and the perfect location. Let’s talk about how to combine these four elements to make your own water garden in a pot.
What kind of pot to use for a water garden
For containerized water gardens, my first choice is to use a glazed ceramic pot, but any water-tight container will do. In the project plans below, I tell you how to seal any drainage holes in the bottom of the pot before you use it. The other option is to select a pot that has no drainage holes in the first place.
Avoid porous pots, such as clay pots, because the water will quickly seep out through them unless you take the time to apply a spray sealant to the interior and exterior. If you want to build a water garden in a half whiskey barrel or another wooden container that may also slowly leach water, line the interior with a double layer of pond liner at least 10 mm thick before filling the container with water.
There are many types of decorative pots you could use for your container water garden. Avoid plastic containers if you plan to have fish in your mini pond because of the chemicals they might leach. And skip dark metal options if possible because the water housed inside of them can get very warm if the pot is kept in the sun.
Where to place your container water garden
A small container water garden is a great addition to a patio, deck, porch, or even as a central feature of your vegetable or flower garden. Unlike ground ponds, containerized mini ponds can easily be moved from one location to another from year to year or even within the same season (though you’ll likely have to drain it before moving). Ideally, choose a sunny location that receives direct sunlight for about 4 to 6 hours per day. In places where there is a higher amount of direct sunlight, algae growth can become problematic, and the water can get too warm for fish and plants. In shadier conditions, many pond plants will not grow well. 4 to 6 hours is the perfect “sweet spot.”
One item of note regarding location: rectangular container ponds with shallow waters on one end or graduated margins of pea gravel that gently slope into deeper water should receive more shade than straight-sided containers since the water in its shallow end will heat up very quickly.
What kind of water to use in a container water garden
When filling your mini pond in a pot, rainwater is an ideal choice. It’s free of dissolved salts and chlorine – plus, it’s free. However, tap water is a fine alternative. Let tap water sit for 24 to 48 hours before adding plants to give the chlorine time to dissipate. If the water level drops and you need to top-off your container pond from time to time, use harvested rainwater or a bucket of tap water that’s been left to rest for 24 to 48 hours.
Is still water or moving water best?
A water container garden can contain unmoving water and still host plants and even frogs but using small pumps or bubblers to cycle the water reduces the chances of algae growth and mosquito larvae. It also infuses the water with oxygen which is required to support fish and keep the water from getting “funky.” A small submersible fountain or pond pump with adjustable flow control works just fine if you have an electric outlet nearby. A pump that produces a flow of 100 to 220 GPH (gallons per hour) placed in the bottom of the pot pumps water up a tube to height of 3 to 5 feet. If your pot is deeper than that, choose a pump with a higher flow rate.
Hook the pump’s tube to a fountain or make your own bubbler using the plans found later in this article. Alternatively, a small floating pond bubbler or mini fountain is another great choice. If it’s solar powered, you won’t need to plug it in which is great for a container water garden that’s far away from an outlet. Anchor the floating bubbler or fountain to the bottom of the pot by tying it to a brick or another heavy object. If you don’t anchor it, it will migrate to the edge of the container and bubble all the water right out of the pot!
If you opt for ummoving water, use mosquito dunks to manage mosquito larvae. These round, donut-shaped “cakes” are made from Bacillus thuringiensis var. israelensis (Bti), a natural larvicide. They float on the surface of your water garden and eliminate mosquito larvae without harming fish or plants. Replace the dunk every 30 days.
The best plants for a container water garden
There are many different aquatic plants that grow well in a containerized water garden. Options include bog plants, aquatic plants, marginal plants (which are species that would be found at the edges of ponds and streams), and floaters, which are floating plant species that drift on the water’s surface.
Select three to four plants from the following list if your water garden holds around 10 to 15 gallons of water. For pots that hold 5 gallons, choose only one or two plants. Really large container water gardens can sustain a half dozen or more different species, depending on their size.
Here are some of my favorite plants for a patio water garden.
- Anacharis (Egeria densa)
- Arrowhead (Sagittaria latifolia)
- Dwarf cattail (Typha minima)
- Dwarf papyrus (Cyperus haspans)
- Dwarf umbrella palm (Cyperus alternifolius)
- Fanwort (Cabomba caroliniana)
- Floating heart (Nymphoides peltata)
- Lotus (Nelumbo nucifera, N. lutea, and hybrids)
- Parrot’s feather (Myriophyllum aquatica)
- Taro root (Colocasia spp.)
- Variegated sweetflag (Acorus calamus variegatus)
- Water iris (Iris louisiana, Iris versacolor, or Iris pseudacorus)
- Water lettuce (Pistia stratiotes)
- Water hyacinth (Eichhornia crassipes)
- Water lilies (many species)
Most of these aquatic plants are available at pet stores, water garden supply centers, and some garden centers. Often they are available from various online sources, too.
Can you have fish in container water gardens?
Small fish are delightful additions to a container water garden. Speak with the experts at your local pet store to find out which species is best for outdoor life in your region. One good option is the mosquito fish (Gambusia affinis), a small species of freshwater fish that eats mosquito larvae. Like other backyard fish, mosquito fish should not be released into natural bodies of water to prevent them from becoming invasive. In my backyard container mini pond here in Pennsylvania, I have 2 small goldfish every year to enhance our water garden’s habitat. We feed them a small amount of pelletized fish food every few days and keep the water moving through a small fountain. The pet store can provide more specific care instructions for whatever type of fish you decide to include.
If you put fish in your container water garden and you live in a cold climate, when cold fall temperatures arrive, the fish need to be moved into an indoor fish tank or into a deeper in-ground pond or outdoor water feature. Yes, regular old goldfish do very well in outdoor ponds and survive the winter just fine, as long as the water is at least 4 feet deep. Like their larger cousins koi, goldfish stay inactive at the bottom of the pod where the water temperature is more consistent. Most container water gardens are not deep enough, hence the need to move them to another location at the end of the season. Thankfully, we have a neighbor with a large outdoor pond and waterfall who always takes our two goldfish at the end of every season and adds them to their large collection.
Have a plan in place for end-of-season care for any fish in your container pond. You don’t want cold temperatures to arrive without a new homebase for your fishy friends. Keep reading to discover DIY plans for building a container water garden of your own.
DIY Plans for a container water garden for a patio, deck, or porch
Here are instructions for building a beautiful mini water garden of your own. It only takes a few hours and will give you months of enjoyment every growing season.
- 1 large non-porous container. Mine holds 30 gallons and is made of glazed ceramic
- 1 tube silicone caulking and a caulking gun if your pot has a drainage hole
- 1 small submersible pond pump with adjustable flow control up to 220 GPH and a ½” tubing adaptor (typically comes with the pump)
- 3 to 4 feet of rigid, 1/2″ diameter clear polycarbonate tubing
- 3 to 4 aquatic plants from the list above
- Bricks or blocks to prop up plants
- Rocks to weigh down pots
If your container has a drainage hole in the bottom, seal the drainage hole with silicone caulk and allow it to dry for a minimum of 24 hours.
Locate the exit valve on the pump. Put the 1/2″ adaptor on it and slide one end of the clear poly tubing over the adaptor.
Place the pump at the center of the bottom of the pot and run the cord up the side and out of the pot in the back. Cut off the rigid tubing so the end sits at a height 2 inches beneath the rim of the pot.
Place blocks or bricks in the bottom of the pot. Arrange the containerized plants on them so the rims of the plant containers sit 1 to 3 inches below the rim of the large pot. Use the plants to hide the electric cord.
Add water to your container water garden until the level covers the top of the clear poly tubing by about a half inch to an inch. Use rocks to weigh down the plant pots if any of them start to float up. When the pot is full of water, add any floating plants such as water hyacinth or water lettuce.
Plug the pump in and give it a moment or two to prime. The water should bubble up out of the tube just below the surface of the water. If the flow rate is too heavy and water shoots out the top of the pot, unplug the pump, lift it out of the water, and adjust the flow rate valve until you reach the correct flow rate. Sometimes this takes a little experimenting. Always unplug the pump before taking it out of the water. Never run pumps when they’re not fully submerged and never adjust the pump while it’s plugged into an outlet. Safety first!
Wait 3 to 5 days before adding any fish. There’s no need to fully swap out the water in your mini pond, but you will have to top it off from time to time. As mentioned earlier, use rainwater or dechlorinated tap water.
How to take care of a container water garden in winter
At the end of the growing season, you have two options. The first is to completely drain the pot and overwinter the plants in a tub of water in a cool basement or garage. They’ll shift into dormancy and just sit there until spring.
Believe it or not, you can opt to keep your water garden pot outdoors all winter long. Use a floating pond de-icer to keep the water surface from freezing solid. Hardy varieties of aquatic plants can be left in the pot without a problem. If you plan to leave your container outdoors all winter, opt for an acrylic, fiberglass, or other frost-proof container. When cold temperatures arrive, turn the pump off, remove it, and take it indoors. Don’t forget to remove the fish as directed earlier in this article if you choose this option.
I hope you’ll consider adding a containerized mini pond to your garden. It’s a fun and beautiful project that enhances any outdoor space.
For more on creating a wildlife-friendly landscape, please visit the following articles:
- Build a pollinator palace
- Create a year-round wildlife garden
- The best plants for butterfly caterpillars
- How to clean a birdbath
- How to maintain birdhouses
- Tips for attracting hummingbirds