Plant varieties within these four categories are what you need to eyeball: deep-water, marginals, oxygenators, and floaters. (If you think these words are big words, just be happy we’re not talking about medicine.)
After you’ve diligently planted your new plants in plastic tubs, pans, or clay pots, packing the fertilizer- and chemical-free soil down tightly, load the container down with pea gravel to keep the soil from floating away. (Don’t ask why this works, but it does.) Plunk your plant into the water at the appropriate depth (You’ll read about that in just a minute) and you’re on ready to go!
Plant-dunking should be generally be done during the growing season. For new ponds, wait four or five weeks for the water plants to do their thing before you add your fish. If you just can’t hold your horses, or your fish, for that long, you can jump the gun a couple of weeks, but the idea is to let the plants first get established.
When picking your plants, you’ll no doubt be wowed by water lilies of the tropical persuasion. These aquatic wonders are popular compared to their hardier cousins with knock-out fragrance, big blooms day or night – depending on the variety – and a habit of blooming their little hearts out nearly every day during the growing season. They love their warmth, though, so unless you live in a year-round, warm-weather climate, be prepared to hasten them into a greenhouse or at least muster up some funds to buy them some “grow” lights to tough it out through the winter.
They will definitely bite the dust at freezing temperatures, but give them night-time temps of at least 65F and daytime temps of 75F or warmer, and your love affair with tropicals will only grow that much more torrid.
Hardy water lilies, while not the showboaters that tropicals are, are . . . well, hardier. Their big advantage is that they can stay in the water year ‘round unless it freezes so deeply the rootstock is affected. And being the tough guys they are, you can plant these puppies deeper than the tropicals, some living it up in depths of 8 to 10 feet.
Both hardy and tropical water lilies are real sun worshippers. At least 5 to 10 hours a day is what it takes, along with regular fertilization, to keep these plant pals happy.
Everybody and their brother with a water garden wants a lotus plant. (Sisters, too, no doubt.) These water-lily relatives come in hardy and not-so-hardy strains, so make sure you know what you’re buying. Much bigger than water lilies, lotus have huge, famously splendid blooms that not only will knock your socks off, but make you forget you have feet altogether. Their leaves and seed pods are so breathtaking, they’re a favorite in costly cut-flower arrangements. Big, bold, and beautiful, with water-depth needs of 2-3 feet, these shouters are really better off in big ponds that get plenty of sun.
Marginals (sometimes called “bog” plants by those less high-falutin’) are grass-like plants that strut their stuff in shallow areas no deeper than 6” that border the water garden. They also do well in mud. Cattail, bamboo, rush, papyrus, and many other plants fall into the family of marginals and grow best with a minimum of at least three hours of sun.
Some plants are there but not seen, working stoically under water and without fanfare to fight algae, oxygenate the water, and provide food for fish. (In lieu of these plants, if your pond is small, you can fake it fairly adequately with an aquarium pump.) Easy on the wallet, varieties of these plants can be bought in bunches and like their soil sandy and/or gravelly. Like hardy water lilies, they, too, will warrior it through the winter.
Water hyacinths have become a recent rage, especially for the lazy among us. No soil is required for these beauties. Toss them in the water and they’re “planted.” A water hyacinth ain’t just another pretty face, though; these plants do their part in the war against algae and blanket weeds by keeping sunlight scarce on the water’s surface. But one note of caution: This plant may take over the world if allowed. It’s invasive as all get out, so keep it under control or you (and your neighbors) may wish you’d never laid eyes on it.
A water garden isn’t a garden without plants. Take your time, know your climate, and choose wisely. Your rewards will be great in return.