If you’ve only grown plants on dry land, you’re in for a treat. Water garden plants are fascinating, fun, and beautiful. Their needs are quite different from other plants. Plants play an important role in water gardens. They take up excess nitrogen in the water (often produced by fish) and filter and purify the water. They shade the water to prevent algae growth and keep any fish cool on hot days.
There are four groups of water garden plants:
Water Lilies and Lotuses
Plant these in pots that sit on the bottom of the pond. Their long stems grow upward, with signature leaves that float on top of the water. They produce stunningly beautiful flowers and some are fragrant.
Marginal Plants
These grow in the “margins” or shallow parts of a pool or pond. They also are planted in pots that rest on a ledge or a stand so that the soil level is anywhere from just an inch to several inches below the surface of the water. Marginal plants also can be grown as bog plants, that is, planted in a lined bed filled with soil retains water to keep the soil extremely wet at all times, mimicking bog conditions. Popular marginal plants include arrowhead, canna, creeping jenny (moneywort), yellow flag, papyrus, and taro (elephant’s ear).
Submerged Plants
These also are planted in pots, placed at the bottom of the pond. Their long stems with leaves trail upwards, but they remain underwater—sort of like the plants you might see in an aquarium. They are very helpful to a pond with fish, since they add oxygen to the water and provide natural cover for fish. Popular submerged plants include parrot’s feather and hornwort.
Floating Plants
These simply float on the water surface, their roots dangling downward into the water. They spread rapidly in warm water and shade the pond, keeping it cool for fish and preventing algae growth. Popular floating plants include water hyacinth, water lettuce, and duckweed.
How to Plant Water Garden Plants
There are special pots made for water garden plants, but you can also use ordinary plastic pots. However, use only black plastic since it blends with the black liner for a more natural look. Plant with ordinary garden soil (not potting soil—it’s too light and will float) or potting soil made specifically for water garden plants. Once you’ve potted a water garden plant, it’s a good idea to add a layer of gravel or small stones to help keep the soil in place.