Water gardening in containers is easy gardening. After all, a pond is simply a big container.
You have to pick your container (obviously you pick something you like the look of) and it has to be waterproof.
I personally like clay pots and I glue-gun some plastic to the bottom hole to make it more or less waterproof. I say “more or less” because clay “sweats” and it will look damp and stain a deck or indoor floor pretty quickly. If you want full water-tight conditions, then use the same glue-gun on a plastic pot. You can find these that look like clay and they work well.
Bigger Is Better
Get the biggest container you can.
You’ll find that large containers look better, they hold more plants, don’t need filling as often and make more of a garden impression. In my opinion, unless you are gardening on a balcony, then bigger is better.
If you are water gardening in containers on a balcony, remember that water weighs approximately 10 pounds per gallon; it’s heavy stuff.
You have two options when it comes to putting in plants. The first is to grow them in the container they were purchased in (or move them into something slightly larger) and place that pot in the water-feature.
Or, you can plant them directly into soil in the container.
I like a combination of the two. The bigger plants such as lilies get planted on the bottom. I put a layer of heavy clay soil or gravel on the bottom of the pot and plant the lily directly into this. I prefer the clay as it gives more food to the plant (lilies are greedy feeders) and I can stick in a feed-stick with no problem (or put compost below the clay). Gravel is pretty porous and putting compost below it or feed-sticks into it is irrelevant — they’ll both leach out quickly to turn your water green immediately.
Do not use a soilless mix of any kind with water garden containers. The light particles (perlite etc) float to the top and they’re a pain to remove. Also water lilies tend to float away with light soils. Use the heaviest clay you can find for best results.
The smaller plants I’ll leave in their pots and sometimes — in larger containers — I’ll stand these pots on upside-down pots to bring them to the proper growing height in the water.
Those heights below the water line are the same for container growing as they are for pond growing (and are generally available on the plant care tag).
Care For Water Garden Plants
Water gardening in containers requires the same care for your plants as for those grown in larger ponds — both for pruning and feeding.
Algae In The Water
A problem you may have is with algae in the water. You simply don’t have enough bio-filtration (if any) going on. I solve this problem by tossing in several bundles of oxygenators from the pond shop. These plants will assist the water in keeping clear.
You can also use barley straw and this can often be purchased at water garden shops.
Control Mosquito Larva
Mosquito larva are controlled by putting in a few fish. Guppies (the cheap kind) and Rosy Barbs are two that I’ve found work very well.
I never feed the fish but allow them to live on the algae and small insects that live and breed in the water.
Do ensure the chlorine is well removed from the water garden container water before you install any fish. The upside to this is that both the guppies and rosy barbs will breed like mad and you’ll have more than enough fish to populate a home aquarium.
Plant selection is water gardening in containers is the same as in-pond growing.
I prefer to grow dwarf tropical lilies in my container water gardens (grow lilies in the full sun if you want to see blooms).
Full-sized hardy lilies make terrible container plants as they don’t have enough room to spread their leaves and gather energy for flowering. They stunt when grown in small containers.
Some waterside plants such as parrot feather can be allowed to twist and turn over the edge of the container.
Floating plants such as water lettuce are good choices for shadier gardens (remember lilies require a full, hot 6 hours of sun a day to bloom).
Tropical foliage plants can be grown as shallow water plants (always assuming they don’t mind wet feet). I personally love growing huge clumps of papyrus in tubs.
And lotus are the queens of the water gardening in container crowd. You can grow superb specimens in a container much to the envy of your neighbours.
With the exception of large, spreading, water lilies — you can grow any water plant you want in your water gardening containers.