I love the look of giant leaves of aroids like Colocasia (shown) and Alocasia looming over the surface of my various water gardens, but always found the “planting” of them difficult: Everybody always wanted to set themselves free and float to the surface, even if I set rocks inside their rims. Naughty babies. So here’s what I do:
First, I hold the plant, black plastic nursery pot and all, under water until it stops bubbling and is fully soaked. Then I simply stuff it, black nursery pot and all, into the heaviest terra cotta pots I have that they barely fit into. (Again, stuff is the operative word, so tight they cannot get loose.) Not your basic flower pots, but the heavy-duty kind, with thicker walls, usually made of slightly coarser clay like those from Impruneta, Italy, or thereabouts.
And next I just lower the whole thing into place in the water trough or pool or pond it’s meant for, sometimes setting it on top of a shelf made from bricks and slates to get it to the right level. (Want to hide the glimpses of the pot rims from view, like you can see in my photo? Dye the water black with fish-safe dye, which also limits sunlight penetration and therefore helps thwart algae buildup.) If you think big-leaved beauties like taro grow well in the ground, you should see them on a steady water diet.