Once you’ve chosen a spot for your container water garden – remember, 6 or more hours of direct sunlight a day, no overhanging trees, and a nearby water source (and power source if you’ll be using a circulating pump for a waterfall) – you get to the fun part. Most home and garden supply store chains carry all the materials you need to create small ponds, including plastic liners – but you’re only limited by your imagination and a few basic rules in choosing a container for your water garden.
It must be easy to drain.
It must be non-porous.
It must be deep enough to support the plants you want to grow.
I’ve seen water gardens that use everything from old bathtubs to an assortment of terracotta pots (with plastic liners) to large baskets (also with plastic liners).
For a container water garden, you won’t actually be planting the plants in the bottom of the ‘pond’. Instead, each plant will be planted in its own separate pot and submerged in the water.
Assemble your equipment
You’ll need your containers, plants, bricks or terracotta pots, gravel, heavy soil, aquatic plant fertilizer tablets and a garden hose.
Pot your plants
If they’re not already in suitable pots, you’ll need to pot your plants. Do not use potting soil, vermiculite or peat moss – all of which will wash out of the pots and foul the water. Instead, you want a very heavy, mud-clay like soil. Fill the pot 2/3 full with soil. Push a fertilizer tablet into the soil, then carefully spread the roots of the plant over the surface of the dirt. Add a few inches of dirt and lightly tamp it down, then cover with an inch or so of pea gravel. Repeat until all of your plants are potted.
Arrange your plants in the container
This is where the bricks come in. The tops of the plant pots should be no more than a few inches below the surface of the water. Stack bricks, upended terracotta pots or construction blocks in the container and place pots on top of them to vary the heights of the plants.