Here you’ll find which water garden plants are best for you.
We’ll talk about three general types: Surface and Potted plants, Oxygenators, and Marginal or Bog plants.
Then we’ll also address what sorts of fish might be good for container water gardening and how to acclimate them to their new homes.
First up are Potted or Surface Container Water Plants:
Water lilies are the most popular water garden plants, of course. But most water lilies are usually too large for a small container planting. Look for water garden plants such as dwarf lilies specially developed for small spaces.
Try these varieties: Nymphaea ‘Laydeken Lilacea’ or Nymphaea ‘Paul Hariot.’ The first one I listed here is hot pink, and the second is white with hot pink flairs. You’ll find more water garden plants in the resources below.
Other water garden plants you can try for surface dwellers include Lotus, Water Hyacinth, and Water Hawthorne.
I’ve grown lots of water hawthorne. It’s very easy to manage and spreads fast, blooming with pretty lavender-blue flowers.
As mentioned in the general set up and planting guide for container water gardening, oxygenating plants help keep algae down and help balance the water’s nitrogen levels.
Typical oxygenating plants include fanwort, hornwart, and anacharis. Anacharis is by far the most prevalent oxygenator you’ll find. It grows completely underwater and you’ve got to keep an eye on it because it spreads.
Marginal or Bog Water Garden Plants:
These grow usually at the edges of bogs, and so prefer their roots and lower parts beneath the water. These include sweet flags (which have thin, vertical leaves), miniature cattails, and aquatic dwarf canna (pictured here).
Other water garden plants include dwarf iris (which I love), pickerel weed, which contrary to how ugly its name sounds, actually has pretty blue flowers. And you might try arrowhead—it has an interesting triangular leaf structure.
Below the dwarf canna is a pretty container water plant called a ‘Snowflake.”
Fertilizing your Container Water Plant:
Fertilizing is tricky. You can very easily over-fertilize because many plants draw their food from nutrient-rich water.
Buy aquatic fertilizer, and follow the directions for best results. Personally, I haven’t used fertilizer at all, but it’s certainly an option.
And if you do fertilize, don’t get concerned if the water is not perfectly clear. That’s normal. 10-12” visibility below the surface is just fine.
One word of caution: Don’t get carried away with the number of container water plants. You can only raise up to about four plants in a pot about 16-18” in diameter. If you aren’t planting a marsh water garden, be sure yours is at least 12 inches deep.
Container Water Garden Fish:
I always let the container water pond sit for a week before adding fish. I’ve also heard you should let it sit for much longer, say 4-5 weeks. The point is to allow the water and the water garden plants to establish a healthy, stable system before you introduce the fish.
You can de-chlorinate the water with supplies from an aquatic nursery or aquarium shop. Still, it’s best to let the pot pond establish itself—good ph and oxygenated levels are essential to the health of your water plants and fish.
If you have a smallish pot, don’t try to raise fish at all.
You should have about a one-and-a-half inch fish for every square foot of water surface. As you can see, in a container water garden, there’s not much room to keep fish healthy.
To be blunt about it: If the pot’s too small it will stress out the fish and they’ll die. An 18-inch pot, for example, will only comfortably house a few small fish.
I’m still waiting for my big water pond because I love koi. For now, little goldfish, guppies, and mollies from the aquarium store will have to satisfy me.
But we can still look at pictures of koi, right? I think this guy has a lot of personality!
Three things are very important if you have fish:
First, make sure to change the water. It refreshes it and also cools down the surface—important in hotter climates.
Second, thin the plants. Both submerged and surface water garden plants (water hawthorne for example) are fast spreaders. Since you don’t want the whole surface covered, thin those plants!
Third, make sure your pond is in a shady place. Full afternoon sun will overheat the water and kill your fish.
Acclimating Your Fish:
When you bring them home from the aquatic nursery, don’t just dump them into the water garden. As in adding new fish to an aquarium, you need to slowly acclimate the fish to the new water.
Begin by adding a fourth-cup of pond water to the plastic bag the fish are in and float it on the surface for about 15 minutes. Then slowly begin to add in more pond water, letting the fish rest in the newly added water each time.
After there is nearly equal amounts of aquarium and pond water, release the fish into the pot.
The fish will feed on submerged material, but you should supplement that with flakes or fish pellets. Just follow the directions.
And take note—I’ve lost lots of fish to night-marauding critters. If you live in an area that has raccoons, for example, don’t leave your fish food out, and cover the container water garden surface with netting or something else open, but secure, at night.
Wintering Over your Container Water Garden:
In a pond, the fish drift to the bottom and hang there in a suspended state during the cold months.
That’s not possible, of course, when you have small container water gardens.
I have wintered over a small in-ground water garden, though I had to discard the container water plants. I think the fish managed well because my water garden was deeper than the minimum fourteen-inches, and I had very small fish.
Just to be on the safe side, the best advice is to bring in your container water plants (or discard them) and the fish. The fish will be fun to watch over the winter in an aquarium and then they’ll be ready for the next season.