Texas AgriLife Extension Service
Texas A&M University, College Station, Texas

June 2008

Landscaping the Aquatic Water Garden: An Aquatic Primer

by Sally Ferguson

Well Landscaped pond
        Well Landscaped Pond

If the mere mention of fragrant night-blooming water lilies, Curly-wurly rush, or color-changing lotus sets your heart pounding, it's too late, you've already joined the legions of Americans now hooked on water gardening and wondering which of the assortment of aquatic plants a backyard pond puts within your reach.

Interest in exotic and native aquatic plants is booming as water gardening climbs the charts as a top gardening activity coast-to-coast. Statistics compiled by the National Gardening Association show water gardening growing at an annual rate of nearly 20% since 1997, with no sign of abating.

Greater demand means there's a lot more exciting aquatic plant material to be found out there. Today's water gardener has their pick of hundreds of aquatic and marginal plants from water lilies and lotus to papyrus, cattails, cannas and more. Water lilies alone now come as day-bloomers and night-bloomers, hardy and tropical, with flower colors ranging from white, pink, red, yellow, purple, blue and orange in hues from pale to vibrant. Some are intensely fragrant.

The Roles Plants Play

For water plant devotees, beauty isn't all that's at stake when it comes to landscaping a pond.

Aquatic plants are great and a lot of fun, but they're also essential elements in a healthy water garden. You need a mix of water plants to help keep the pond ecologically balanced and provide needed shade to keep fish happy and water cool and fresh.

For the average home pond, it's a good rule of thumb to have at least 40% to 60% of your water garden's surface covered in floating vegetation, plus a variety of underwater plants.

Water plants help keep water clear by playing a role in biological filtration. Through various means, aquatic plants draw away excess nutrients and waste products such as nitrogen, nitrates and ammonia out of water that would otherwise cause algae growth. Marginal and submerged plants play different roles in providing shade, food and protection for fish and other pond-side wildlife, while also providing spawning areas for fish and frogs.

A Quick List of Pond Plants

Following is a quick run-down of the major types of plants for use in and around a water garden from Chris Wilson and the experts at Aquascape Designs:

  • Water Lilies - The water lily is the crown jewel of the water garden and the most popular water gardening plant. Lilies provide a lovely floating carpet of leaves and flowers across the surface of a pond. They also provide fish with a shady awning from the summer sun while depriving algae of the sunlight needed for growth. There are winter hardy and frost-sensitive tropical varieties.

  • Hardy Lilies - Hardy lilies are reliably perennial from USDA zone 3 through zone 11. Hardy lilies typically bloom from May through September. When cold weather comes, the foliage dies and sinks to the bottom. New leaves will begin to arise from the submerged rhizomes the following spring.

  • Tropical Lilies - Tropical lilies produce fragrant and vibrant colorful blooms. The flowers, usually carried above the water surface on strong stems, come in brilliant whites, yellows, pinks, reds, and lilacs. Tropical lilies are only hardy in USDA zones 10 and 11. In colder zones, tropicals are most often treated as annuals, though they can be brought inside and over-wintered with proper care. Tropical lilies are either day bloomers or night bloomers. Day bloomers flower in the early morning and close in the late afternoon/early evening. Night bloomers open in the late afternoon/early evening and stay open until early next morning.

  • Lotus - The lotus is noted for its magnificent flowers. These exquisite flowers have circular leaves and fragrant flowers. Even their seedpods are interesting, and often are used in dried flower arrangements. This plant should be kept in a pot, as it is highly aggressive.

  • Hardy Marginal Plants - Marginal plants grow along the perimeter of ponds, lakes, wetlands, and streams. Marginals soften the hard look of rocky edges and create a smooth transition from the water to the planting areas surrounding the pond. Marginals help shade a pond and can be part of the natural filtration of a bog area. Most marginal plants like one to eight inches of water.

  • Tropical Marginal Plants - Tropical marginal plants originate from subtropical and tropical regions and are not perennial in cooler climates. A common practice is to leave these tropicals inside their pots and stack small cobblestones around the outside to disguise the pot.

  • Floating Plants - These plants, which float on the water's surface with their roots dangling below, provide shade for pond water and also absorb excess nutrients there thus making summer algae control easier. Most are tropical, but some are hardy. In colder climates, tropical floaters should be treated as annuals to be replanted each year or over-wintered indoors. In ponds with skimmers, avoid planting where floaters can drift into and clog the skimmer.

  • Hardy Submerged Plants - Submerged plants are often the most overlooked plants in the water garden. Because they are under water, they typically don't grab the onlooker's attention like the lilies and marginal plants do. Yet, these plants are important allies in creating a well-balanced water feature. Also known as oxygenating plants, submerged plants help reduce algae by directly competing for common food sources. Think of them as nutrient sponges. They also provide protection and coverage for small fish and fry. They can be planted by simply pushing a bundle of plants right into the gravel, or tucking them around the edges of a lily pocket.

Note: This article was reprinted with permission of AquascapeDesigns, Inc. View their website at www.aquascapedesigns.com

Earth Kind uses research-proven techniques to provide maximum gardening and landscape performance while preserving and protecting the environment. For more information on Earth Kind Landscape Management Practices see our web site: https://earthkind.tamu.edu