Cardinal Plant

Most of my plant purchases have been impulse buys - not exactly the best strategy when dealing with chain pet stores. Quite a few of their "aquatic plants" are grown emersed (above water) meaning that their foliage will die off in the process of converting to immersed growth, if the plants are even capable of that. I got suckered by a PetSmart potted "Cardinal Plant" - helpfully labelled "true aquatic" - which is a lie. The plants in those little plastic pots are emersed growth - cardinal plants are native bog-dwellers - you can tell by the pretty purple-red that the underside of the leaves have. True immersed growth of a cardinal plant lacks the red pigmentation and is instead a bright green. However, rather than returning the plant, I decided to keep it and see if it would make the transition. The main root mass died away, but I spotted some aerial root growth, so I uprooted what was left in my sand substrate and cut the plant stem apart to form many smaller plants, which are actually putting on the proper bright green leaves of immersed growth. Here's how they look now:



There's still some emersed-growth leaves hanging on, but I read that stem plants such as cardinal plant have to be pruned rather aggressively to maintain good aesthetics. That's certainly true of Hygrophilia difformis, or water sprite, as you can see in some of my previous photos, where they look like trees with bare lower stems. I ended up following the "aggressive pruning" strategy, whereby one cuts off the leafy tops and replants them to achieve nice-looking bushy growth. Since switching to a shop light, I think the growth has become even bushier - the plants no longer seem to be rushing towards the light. (In fact, one of the stems kinked sideways of its own volition about the time that I switched from T12 lighting to T8 lighting.) I hope the higher light will allow thicker growth from now on.