Design a soothing water garden
When it comes to having a successful water garden, one of the best investments a gardener can make is to buy a fishing license. Planning a water feature to look natural takes a bit of observation of naturally occurring ponds. Water features are popular in many gardens because they offer enjoyment for many senses and add an element of adventure to the yard.
Well-designed ponds use moving water to create a restful and soothing sound. The secret is to design the moving water portion of the feature to sound like a brook-like trickle, not like a reminder to go to the restroom. Typically, this can be accomplished by adjusting the water pressure on the pump to will allow enough water to flow over the rock or out of the fountain to mimic the sounds of a natural creek. Most pumps have speed adjustors to help regulate the flow, and gardeners should keep in mind that pump size is everything. Too often pumps are undersized for the amount of water that needs to be moved in the pond, resulting in fountains that dribble water, rather than triumphantly jet it.
There are a number of fun plants to investigate for backyard ponds. A good balance of plant cover to open water will help the pond develop an environment that will host a healthy ecosystem for fish and other aquatic visitors. Water lilies, with broad leaves and cup-like flowers, are a favorite, but gardeners should carefully check the space requirements for the type of lily they are buying. If the package indicates that the plant requires 6 to 12 feet of room, they mean across the surface of the pond. Should the water feature be smaller, such as a large container or barrel, water poppies with lily-pad-type leaves could be a good substitute.
Cattails, cannas and dwarf papyrus make outstanding additions to the shallower ends of ponds. Their upright growth gives a natural feel at the edges of the pond and provides perching spots for dragonflies and damselflies, two important predators of mosquitoes. The plants are typically potted in containers with heavy soil and submerged 3 inches. Grouping the plants in clusters rather than spacing them evenly will create the illusion of a natural pond.
Watch those mosquitoes
A common concern for backyard water features is mosquito control, which the pond owner should take this seriously. Several approaches, applied together, can help reduce or eliminate the possibility of the water feature becoming the mother ship for these pesky creatures.
One of the easiest and most readily available types of control is the use of Bacillus thuringiensis (Bt), a naturally occurring bacterium that affects the central stomach of certain insects, giving them — quite literally — a killer stomach ache. Bt is available in donut shaped rings that float in the pond, emitting this bacteria into the water in which mosquito larvae develop.
Bt is harmless to mammals, birds and fish, which brings us to the second prong of defense against mosquitoes — predators. Fish in the backyard pond add beauty and grace within the water and can be rapacious predators of mosquito larvae.
Many of us are familiar with koi, with their bright colors and long, flowing fins, but there are far more efficient fish for mosquito elimination, such as trout fingerlings, young sunfish, and Gambusia. The mosquito-eating fish Gambusia (a relative of guppies) can be effective but are not used widely in Colorado because they are not able to survive the winter, and most people object to the concept of having annual fish. There are, however, a few types that are hardier and may do well in ponds that are in protected locations. As for using trout fingerlings and sunfish, consult the Colorado Division of Wildlife for restrictions and regulations before using them for mosquito control, and keep your fishing license up to date.
Carol O’Meara is with the Colorado State University Cooperative Extension office at the Boulder County Fairgrounds in Longmont. Colorado State University Cooperative Extension, together with Boulder County Parks and Open Space, provides unbiased, research-based information, about consumer and family issues, horticulture, natural resources, agriculture and 4-H youth development. For more information contact Cooperative Extension at the Boulder County Fairgrounds, 9595 Nelson Road, Box B, Longmont, 303-678-6238, or visit www.coopext.colostate.edu/boulder.