Nuts and Bolts of Water Gardening

Source(s): Tony Johnson, College of Agricultural and Environmental Sciences, Horticulturist, UGA Research and Education Garden


Location, Location, Location. No, this is not about Real Estate. Planning and site selection are the most important steps in building a water garden. Poor planning causes many of the problems of installing and maintaining a water garden. Before you put a shovel in the ground know what you want to create.

waterfallDO NOT locate your water garden in a low area. You must make sure that surface water does not get into your pond and contaminate the system with fertilizers, chemicals and silt which will, in turn, damage water quality, fish and plants.

If you want a water garden with lots of blooming plants, the site must have a minimum of 6 hours of sunlight per day.
It is possible and sometimes desirable to have a water garden in a shaded area, but be careful not to damage tree roots; and remember, you will have to cope with more leaves and debris. Water gardens can be landscaped with woodland plants and the shade will help reduce the free-floating algae.

If you want a waterfall or stream effect, make sure you have some type of background such as an existing slope or one created with the soil you excavate. Use some type of evergreen planting to soften the slope.

The water will always be level. Make sure the edges of your water garden are level, too! Spend time making sure your water garden is level and the rest of the installation will go much smoother.

Be sure to use liners that are fish safe, such as Permalon or EPDM. Liner Size = Maximum Length of the pond + 2 x Depth of the pond + 1 Foot x Maximum Width of the pond + 2 x Depth of the pond + 1 Foot.

In the south, a depth of 18 to 24 inches will be fine for fish other than Koi. Koi ponds need to be deeper (3 to 4 feet). Amount of water in pond (Length x Width x Depth) x 7.5 gallons. Other organic material, such as leaves and dead plant material becomes food for free floating algae.

If your water garden is in full sun, 60% of the surface should be covered in plant material. This will shade the free-floating algae. Black dye can also help shade the pond in early spring before the plants fill out. Use one bunch of anacharis per sq.ft. of surface area.

Hardy Water Lilies will survive winter but tropicals will need to be protected or replaced each season.
A skimmer is recommended to help keep leaves and other debris under control. Also it is a convenient way to hide and protect the pump.

Some type of bio-filter is recommended to help keep the water quality safe for fish and to help remove excess nutrients. Most UV lights only cover up problems with water clarity. If you have enough plants and do not have an over population of fish or over feed them, you should be able to keep you water clear.

Set pond plants in pots with solid sides and bottoms, use a non-organic soil and then cover the pot with river stone to prevent the fish from stirring up the soil. This will help keep the water from being cloudy.

Fertilize plants once a month during the growing season with plant fertilizer tablets.

DO NOT drain your pond each year. Take about 20% from the bottom. Use a dechlorinator to remove the chlorine from the water you use to refill or top off your pond.

Most aquatic plants can be invasive, never discard plants around or in natural water systems, such as streams or lakes. The best place to dispose of them is your compost pile.


Center Publication Number: 88