A Plant-Only Aquaria

You find them in doctors’ and dentists’ offices, as well as Thai and Chinese food restaurants. They also often have a place in elementary school classrooms. The allure of an aquarium is nearly universal. Most aquaria are designed to keep their finny occupants happy and healthy. Plants may be included to help with that but usually are not the stars of the show. Given the ease of keeping the plants growing and the problems that can develop to threaten fish, I propose that aquaria that are devoted solely to plants can be just as colorful and interesting as those that include exotic fish.

Almost any clear vessel can serve as an underwater plant display. The traditional glass and acrylic tanks are easy to find (check out the swap meet and Craig’s List before buying new). “Fish” bowls come in many sizes as do glass cylinders and tubes normally used as vases for floral arrangements. Once you start looking, you will find lots of options for your new endeavor.

The variety of plants available these days is truly astounding. Mail order suppliers list dozens of kinds of dozens of species. Here are a few easy ones to start with. Most of these will require nothing more than the water and some gravel to hide their bottoms (many submerged aquatic plants don’t really have roots). Suppliers will note which ones need a more fertile substrate and be happy to sell you some. Placed in a bright window, most species will grow quite well. You may want to invest in an aquarium light if you don’t have a bright enough spot.

Some of my favorites are in the genus Vallisneria. They are generally strap-leafed plants that grow in a clump and are sometimes called eel grass or tape grass. Vallisneria gigantea is the largest with leaves that can reach three feet in length or more-best suited for the outdoor pond, perhaps. Its smaller cousins, though, can grace your tabletop display. Corkscrew vallisneria (V. americana) has nicely twisted leaves that top out at two feet or less, V. spiralis is also somewhat contorted and a little smaller at under two feet. The most twisted of all is V. asiatica, whose very narrow leaves make many revolutions.

An easy-to-grow genus with many species to choose from is Echinodorus. Although there are some species that emerge from the water with leaves and flowers, there are many more that remain underwater all or most of their life. All are generally known as “swords” referring to their sword-shaped leaves. Most are under a foot in height, but there are some that grow to nearly two feet. Their leaves are varying shades of green as well as a few displaying red spots or reddish leaves overall.

Cryptocoryne wendtii is another beginner’s plant. It grows well under many conditions, from low to moderate light and in acidic to slightly alkaline water, and in a wide range of temperatures (from 68 degrees F to 92 degrees F). Anubias ‘Nana’ is another small favorite. Its spatulate leaves grow in a dense clump. The Java fern, Microsorium pteropus, is a true fern that lives its life below the water’s surface. Its leaves are undivided but somewhat translucent, and the sporangia (reproductive structures that produce spores) line the edges of the leaves with tiny black dots.

Some aquarium plants have two distinct types of leaves, the submerged ones and another form that reaches the surface of the water to float there. Aponogeton natans is one such species. The below-surface leaves are wavy-edged and sword-like, while the floating leaves are boat-shaped and attached to the roots by slender stems. One species of tropical water lily can be coaxed to make mostly underwater leaves if the floating ones are consistently removed. Nymphaea zenkeri is sometimes known as the tiger lotus or tiger lily. There are spotted-leaf and red-leaf forms that grow quickly and put on quite a show.

The most common aquarium plants for many years were those that have many tiers of fine leaves radiating from the central stem. An example of these is Limnophila indica, sometimes known as ambulia. Anacharis (Egeria densa and E. naja) is very forgiving and widely available. Cabomba is not a new Latin dance, but rather a very fine-leaved underwater plant, Cabomba caroliniana. Hornwort (Ceratophyllum demersum) is a good candidate for the cooler aquarium.

Whether you grow a single specimen eel grass in a tall vase or create an entire aquascape behind glass, growing these aquatic plants is easy and rewarding.