Water Gardens Swim in Beauty

One of the biggest trends in landscaping today is the backyard water feature. The soothing sound of running water, the fish and other wildlife, and the lure of lotus and water lilies present an enticing image. Whether a whiskey barrel loaded with lilies or a fifteen-by-twenty pond full of fish, homeowners are discovering the pleasures of water gardens. Magazines like The Aquascaper, Water Gardening, Aquascape Lifestyles, and Watershapes seem to be emerging like string algae in a poorly balanced pond, and the internet is teeming with watergardening sites, including koi and water garden clubs.
What do we mean by water garden? There are ponds, pools and fountains. There are waterfalls, streams, and bogs. Although the use of water in the landscape has grown in all of these areas, it is the backyard water garden that gets the most attention. By water garden, we are referring to a balanced ecosystem involving plants, fish and water. Quite often the pond incorporates a bog edge, or a stream and waterfall, and some argue that the best ones must include all of these features.

The sudden popularity of water gardens has many reasons. First and foremost is awareness. Although people have long been drawn to water, until recently, the water feature was never considered a viable element in the landscape. With new technology, innovations in filtering techniques and research in plant and wildlife habitat, the back yard water garden has become an attractive amenity. More people in the industry are looking to make it easy for the homeowner, resulting in more innovation, and more attention paid to what plants work, how ecosystems work, and how to make these things work in a designed environment. Also, as Curator of Aquatic Plants, Bob Kirschner at the Chicago Botanic Garden states, “Designers are making them look better.

Elements of a Water Garden

In addition to the obvious, water, a naturalistic water garden typically has three key elements: fish, filtration, and foliage. This is as true for the back yard pond as it is for the smaller, balcony-or patio-friendly container water garden.

Whether you have fancy koi, or pet store goldfish, fish bring some life to the pond. Sitting or standing at water’s edge and hypnotically watching them is like watching a campfire. It is fascinating, and calming. Certain fish, koi in particular, have been known to disturb plants and muddy the water. It is said that koi and plants don’t mix, but that does not deter enthusiasts from combining them anyway.

You will definitely want plants in your pond. Other than the beauty that plants provide, they also contribute to the ecological balance of the pond. Plants like water hyacinth, water lettuce, and Silvinia, “all eat the same things as algae,” as Rick Walsh of Northbrook-based RikRock, Inc. states. So they will compete with algae for food. Since these plants are not cold-hardy, they cannot be placed in the pond before Man and must be removed before the first frost. Kirschner stresses the importance of removing these plants before they die for the same reason you should manually remove any string algae that develops: These plants feed on and store certain nutrients. When the plants die, the nutrients are released back into the water for next year’s algae to feed on. Walsh also recommends that two-thirds of the water’s surface be covered with plants. The shade helps cool the pond, and discourages algae growth.

Mechanical VS. Biological Filtration

Mechanical filtration is what happens in your coffee maker. It also happens in nature, but it takes a long time. Fortunately, it is easy to replicate in a man-made environment. One innovative product in recent years has changed the way back yard ponds are built and maintained. Its design is based on the concept of a swimming pool skimmer. The recirculating pump sits in a box that is adjacent to the pond. Water is pulled through mechanical filtration media before it reaches the pump. This effectively removes debris like leaves from the water before it can clog the pump. Because the pump and filter media sit outside the pond, it is easily accessible for maintenance. A skimmer box is “the single most important investment you can make in your enjoyment of a water garden”, states Walsh emphatically.

Biological filtration, which relies on an environment of plants and microscopic bacteria, also takes place in nature. Likewise, it is also fairly easy to duplicate, and in fact, biological filtration is used in waste water treatment plants. Biological filtration is achieved a number of different ways. There are external systems that sit outside the pond and pond water is recirculated through them via a pump. Other pre-fabricated systems consist of a plastic box that is designed to be the “header pool” for a waterfall. Walsh uses neither, but creates his own “header pool” which he believes gives him control over how it looks. In all cases, the biological filter serves as an environment for the colonization of microscopic bacteria that feed on nutrients in the water, and thus, compete with the algae. Combined with a skimmer box and the right plants, a biological filter will help keep your pond as clear as possible.

Misconceptions
There is a lot of information floating around regarding water gardening. Some of it can be a little misleading. Professional pond builders have heard them all:

“Raccoons will eat my fish.” This is something Walsh hears a lot. Though common with shallow, preformed ponds, he say that with a well designed pond with a rubber liner, one won’t have this problem.

“Won’t the fish freeze in the winter?” Actually, these ponds don’t freeze solid to the bottom. If it freezes more than six or seven inches deep, that is unusual. Most fish can stay in the pond all winter. You can even run the pump all winter, but make sure the water level doesn’t drop too much. And, don’t fee the fish in the winter.

“What do I do about mosquitoes?” Both Kirschner and Walsh confirmed that, as long as the water is moving, mosquitoes won’t breed there. Walsh recommends enough pumping capacity to “turn over” the entire contents of the pond every hour.

“Smaller ponds are easier to maintain.” Kirschner recommends that beginners start with the whiskey barrel version. “It is an ideal way to learn about aquatic gardening.” In fact, the Chicago Botanic Garden offers classes in this type of garden. Walsh, on the other hand, says that 35% of his clients are people who already have a pond that they are not happy with. Some he completely replaces and some are retrofitted with a filter system. Yet most are made larger. For a back yard pond, the bigger it is, the easier it is to keep it ecologically balanced.

“What about algae?” Filtering and balancing a pond properly helps a lot. But, as Walsh says, “You will always have some algae in a pond. It’s a good sign; it means there is life.” He adds, “Every water garden goes through an algae bloom once a year. Let it run its course and it should clear up in 10-14 days.” The “algae bloom” or plankton bloom, results in green water. The number one mistake people make when they have green water is to replace the water. Tap water is high in the nutrients that algae feed on. Both experts suggest that filamentous or “string” algae be removed manually. A rake is a good tool for this job. “Think of it as the equivalent of weeding in the aquatic garden,” suggest Kirschner. Removing the algae, like removing floating plants before the first frost, also removes the nutrients that they have taken in, thereby starving future generations of algae.

“We have a low, wet area in the yard that would be great for a pond.” This is the absolutely the worst place to build a water garden, according to Walsh. Not only do you not want storm water to muddy your pond, but it can collect under a rubber liner and create bubbles.

“Isn’t it a lot of work?” “With a well-designed and well-built water garden, using the latest technology, maintenance should only be five or ten minutes per week, as opposed to the two or three hours it used to take,” says Walsh. Obviously, leaves in the fall and perhaps a spring clean-out will take a bit more effort, but the day-to-day time spent with your water garden should be more enjoyable.

Article by Tim Thoelecke, Jr – Crain’s Magazine July 2001

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