As anyone who has snorkeled can attest, the cool aquamarine light underwater casts an enchanted glow on everything in its domain. Perhaps this explains the allure of water gardens. Small freshwater gardens are fun to create and simple to care for. And all you need are a few floating or submerged greens in a vintage aquarium, an apothecary jar, or a sleek glass cylinder. You’ll find appropriate containers at antiques shops, garden centers, or in your own cupboards. Aquarium suppliers and specialty nurseries sell a variety of suitable plants.
Those that can remain entirely submerged in water, such as anubias and parrot’s feather (Myriophyllum), are known as true aquatics. Semiaquatics, such as sweet flag (Acorus americanus) and umbrella palm (Cyperus papyrus), like to have their roots submerged and their foliage above the surface. Floaters, such as water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes), drift freely on the water’s surface. A few plants, including dwarf arrowhead (Sagittaria natans) and parrot’s feather, are so adept at converting carbon dioxide into oxygen that they are referred to as oxygenators. They help to keep water free of algae, which can loud the water and kill the plants. You can use any of these-singly or together-in a water garden.
When choosing plants, keep in mind that some will need twelve hours or more of bright light daily. Place these beneath fluorescent grow lights from an aquarium supplier. Avoid using incandescent lights, which can overheat the water and burn foliage. A few species, including sweet flag and arrowhead, can survive on a bright windowsill. Some water-garden favorites, including lace plant (Aponogeton) and sword plant (Echinodorus tenellus), have difficulty setting down roots in soil; place them in gravel or in other loose substrates available at aquarium suppliers.
Read more at Marthastewart.com: Indoor Water Gardens – Martha Stewart Home and Garden