Simple Aquascaping of Your Retention Pond Using Native Plants

By Ernie Franke

Someone recently called for advice on beautifying the retention pond next to her home. As I was discussing a few options I realized that she was trying to get it all down in notes. I also had a difficult time transferring the vision of what it could look like. It occurred to me that I could make it easier to understand aquascaping, the art of adding plants to a water environment. I spent some time thinking about it and came up with the top three rules of aquascaping and my top 10 favorite plants.

It takes a while to identify plants. The good news is that once you start identifying plants, the sooner you start noticing them everywhere — retention ponds, ditches, abandoned fields and local parks. We want to take you out of the textbooks and into the local state, county and city parks to see what the final results will be.

I also realized it takes a while to talk "plant language." At first it appears to be overwhelming with so many options — which plants to choose, where to buy plants, how to arrange the plants, and how to plant them. Many folks don't know where to start. Hopefully, these rules and recommendations will make it easier for non-experts to select and plant robust, non-invasive, Florida-native plants that will give their aquascaping project the greatest chance of success.

From large backyard ponds to retention ponds, there are many reasons for adding aquascaping — from providing a habitat for water fowl and other living creatures to providing a filtration system. Adding native, non-invasive plants literally brings a pond to life.

Florida's Retention Ponds

Florida has retention ponds everywhere. Some are maintained, others not so much. As the economy falters, we will see less maintenance and more reliance on chemical control of weeds and algae. The visual appeal of a lakeshore often includes aquatic plants, which are a natural, critical part of a lake community. Plants do more than give us pleasing vistas—they are havens for wildlife and birds. Fish rely on aquatic plants for food and habitat. Insect larvae, snails, and freshwater shrimp thrive in plant beds. Submerged plants also provide habitat for many insect species and other invertebrates that are, in turn, important foods for brooding hens and migrating waterfowl. Plants improve water quality by absorbing nutrients and pollutants. They protect the lake shoreline by holding soil on the lake bottom and water's edge—which in turn reduces erosion. Aquatic plants are an important part of the lakeshore environment. Exotic plants will have a much harder time taking root in areas where native plants are abundant. A pond looks prettiest when it's flanked with plants, and wildlife prefers the protection they offer.

The modern trend is to prefer absorption of stormwater run-off into the natural water table in a decentralized system, so many local governments impose retention pond requirements as a condition of development, even if storm sewer facilities are available. Many modern office park water features, such as small lakes with fountains, are actually government-required retention ponds. They are often created near development areas and have been gaining in popularity to the point they are typically required with new development of buildings, parking lots and roads.

Which brings us to the First Rule of Aquascaping: You need to get permission to do any work in a retention pond. Regional, county, city and residential authorities plan and control retention ponds.

Retention ponds are often fairly small in total acreage, typically less than an acre. They are also usually shallow with slow sloping bottoms, needed for safety if people happen to fall in. To imitate a natural pond and maintain a healthy ecosystem in your water garden pond, you will want a balance of submerged plants, floating plants and plants that usually grow at the edges of a pond. Each one has a different function and will help keep your pond clean and disease free.

What Plants to Choose

Selecting plants for your pond involves consideration of several factors, including the size of the pond, the depth of the water, and the amount of sunlight. We have chosen ten plants that can be used along shallow lake and pond shorelines in Florida. We have chosen these plants because they are native to Central Florida, love full sun, are robust and grow easily, and are readily available. These plants are perennials, but are dormant during our mild winters, where the roots or rhizomes remain alive. One problem with using native plants is that they're not very colorful. After a while, you'll start to notice the color more. Other people won't notice as much as you will, because you've been trained to notice.

Second Rule of Aquascaping: Always select native, non-invasive plants.

Plant a few, as they will naturally multiply fast. Selecting native plants promises that they will be robust and quickly multiply. A few canna plants, for example, quickly spread to fill in, and provide even more plants for dividing. Some plants, such as iris, may take a few seasons to really start growing. Another advantage to my "Top 10" plants is that they can be propagated by simply dividing the existing plants. You don't need messy pots, just divide the plant with a small shovel, stick the new plant in the muck, and lovingly pat it firmly in place at the same height as the original plants.

List of Recommended Plants: These perennial plants can withstand variable flooding. All are Florida-native, plus they like full sun.

1. Pickerelweed grows three to four feet tall in shallow freshwater. Usually, you only see one or two feet, because the rest is underwater. Its lance-shaped leaves are large, up to five inches wide, and are usually twice as long. Each flower lasts only one day. The easiest way to recognize pickerelweed is by its spike of violet-blue flowers, blooming from March to November.

Pickerelweed is commonly found growing in streams, marshes, ditches, ponds and lake margins nearly throughout Florida. It is a prolific grower that can cover large areas, blooming from spring to summer. The nectar of the flowers attracts many insects, including bees and butterflies. Rhizomes grow in the muddy bottom and spread with roots to send up more stems to the surface. The seeds are a good food source for ducks and muskrats, while the leaves and stems provide good cover for birds, swimming mammals, fish, reptiles, amphibians and insects. Apple snails lay eggs on stems; and butterflies are attracted to this plant. Pickerelweed reaches out from the shallow water to the water lilies in the deeper section.

2. Arrowhead / Duck Potato: Despite the name, ducks rarely consume the tubers, which are usually buried too deep to reach, although they often consume the seeds. Duck potato grows commonly in swamps, ditches, lakes, and stream margins. Its large, distinct arrowhead-shaped leaves and conspicuous three-petalled, white flowers make it easy to find in the wild. Flowers are extended on thick stalks that are often a foot or more above the leaves. Waterfowl and mammals feed on the seeds, while the flowers attract butterflies.

3. Alligator Flag / Fire Flag grows up to 9 feet tall from a thick rhizome, growing in swamps and wet ditches, blooming from summer to fall. Large simple leaves on long stalks are among fire flag's most notable features. The leaves are lance-shaped, with broadly rounded bases. Multiple small, three-petal purple flowers hang from the bracts, attracting butterflies.

4. Southern Blue Flag is a tall wildflower with pale green, sword-like leaves in strong, flat vertical fans. It occurs naturally in wet areas like ferns, marshes, bottomland prairies, and at the edge of ponds and streams. The showy flowers are deep blue-violet with yellow and white markings, growing on stems up to 3 feet tall. It prefers moist, rich soil where it forms colonies and can be used in bog or water gardens. Blue flag is a sturdy plant that is easy to grow and, once established, needs very little care. To propagate by division, divide the plants every three to five years to thin out the colonies, either after flowering or when the new leaves just begin to appear in the spring. Attractive flowers grow in clumps and attract butterflies.

5. Golden Canna is a showy, native plant which typically grows to four feet tall. Golden canna lily flowers are yellow, occurring naturally in wetlands, including marshes, savannas, and the edges of ponds and lakes.

6. Sand Cordgrass is a large bunch-forming grass that grows 4 to 6 feet tall. The leaves are rolled, almost wire-like and a little sandpapery (but not sharp) to the touch. The stems and leaves arise in a dense cluster and curve out and down to take up a space equal to the clump's height. The whole plant is brownish-green: more green in summer and more brown in winter, but never as brown as pampas grass gets in winter. Sand cordgrass grows in brackish marshes, but also in freshwater marshes and lake margins. Propagation is accomplished by dividing pieces of the root in summer. Birds feed on its seeds.

7. Horse Tail is an ancient, fern-like evergreen, reaching a height of 3 feet and forming colonies. It is dark green with jointed or segmented stems 1/4 to 1/2 inch thick with no true leaves. It grows in sandy soils of floodplains, lake edges and sloughs, providing food for waterfowl and mammals. Horsetails can be found standing in water or in wet areas. Horsetail stems contain silicon crystals (sand) embedded in its tissue. This gritty texture gives it the common name of "scouring rush." It is eaten by waterfowl and mammals.

8. Spatterdock (Cow Lily) commonly occurs in ponds, lakes and sluggish streams in Florida and blooms from spring to summer with large heart-shaped leaves. Spatterdock floating leaves are attached to long, stout stems which arise from large, spongy rhizomes. Spatterdock flowers are yellow and "half-opened" at or above the water surface. Flowers are attached to thick round stems that are often six feet long. Spatterdock may be confused with the yellow water lily. Spatterdock leaves tend to stand up, while water lilies lie flat. The spatterdock produces yellow buds, which never bloom forth. Waterfowl feed on its seeds.

Out of all the aquatic plants you might use in or around your pond, water lilies probably are the most easily recognizable and widely used. Although they come in many different colors, I have limited my list to only native plants, which includes the white fragrant and the mexicana yellow.

9. The White Fragrant Water Lily has white very fragrant flowers (spring to fall) and smooth leaves. Ducks and mammals feed on its seeds and stems. The roots of floating-leaved plants provide a stable surface for successful fish spawning.

10. The Yellow Water Lily is more robust, often crowding out the more elegant white fragrant. This plant is dormant in winter. Mammals and turtles feed on the leaves.

Native, non-Invasive, Central Florida, Emergent Plants

Where Can I Get Plants? Third Rule of Aquascaping: Don't get plants without permission, or you may get a free trip to jail.

If you want to buy a few plants, we recommend using one of the shops that support the Florida Native Plant Society, found at http://floridagardener.com/FLNatives/NPS.htm. For larger purchases of a dozen or so plants, it would be worth it to drive down to the Myakka area to visit Florida Native Plants Nursery, 730 Myakka Road, Sarasota, Florida 34240 (http://www.floridanativeplants.com/) or Aquatic Plants of Florida, Plant Farm (closed to the public, by appointment only), 8305 Wauchula Road, Myakka City, FL 34251 (http://apofl.com/).

Where Can I See Aquascaping?

As you drive, bicycle or walk, you start noticing the vegetation in ditches and retention ponds. You'll also notice what is done at city, county and state parks. You will notice several things; that plants occur in an orderly fashion and some plants dominate the setting. Also the plants provide an interface between water and land. Contrast that with the "dull" pond that merely has grass or weeds at the water's edge. What we desire is a natural, non-chemical approach, hopefully requiring less overall maintenance.

State, county and city parks are listed on local map books available at department stores, or simply by Googling the subject. The pond at Walter Fuller Park in St. Petersburg, an oasis in an urban setting, is a favorite example of aquascaping a retention pond.

Ernie Franke is a retired electrical engineer who aquascaped "his" pond at The Shores in St. Petersburg beginning in 2009. He wrote his first article for Bay Soundings in the summer 2010 edition. Email him with additional questions at eafranke@tampabay.rr.com or call 727-393-8639. He also recommends Aquatic Plants of South Florida from the Florida Fish and Wildlife Conservation Commission at http://myfwc.com/media/617887/AquaticPlantIdentifier.pdf.