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Water Gardening by John Atlee Water in it’s many forms has fascinated people from early childhood to old age. We have all been beguiled, at some time or other, by cascading waterfalls, placid streams and the calm and stillness of a simple pond. Water has always played a part in the garden. Ancient cultures manipulated water courses to bring the precious material into their cities and towns. It nourished their gardens and their cultures. Water gardening has a long history in many cultures. In China and Japan it is considered an art form in an almost reverent sense. In Europe it played with peoples sense of splendor and grandiosity. In many middle eastern cultures it offers welcome respite from the prevalent heat and strong sunlight. Water gardening can be as simple as a tub of water on the patio to elaborate water courses flowing from level to level defining our garden’s design and our personal comfort. Selecting a site for a water feature or water garden is generally determined by the existing landscape. Determinations should be made concerning weather and climate, sunlight, surrounding trees and shrubs along with other plantings, available space and financial considerations. Also you will need to consider what you will be growing in the water. Water lilies require almost full sunlight to bloom and prosper. Fish will need some kind of shelter to hide and seek safety provided by either plants or shade. If you choose to grow the tropical pond plants you will need a warm location to over winter them, such as a greenhouse or other shelter that will protect from frost. You will also need to consider the construction site. Trying to build a 4ft. deep pond in sand will be almost impossible. The more you dig the wider the sides will become, especially if the sand is very dry or water logged. Likewise it would also be difficult to try and excavate a rocky area that consisted of boulders and tree roots. In difficult areas you might consider building the pond above ground rather than in the ground. Planning a pond you will need to develop some ideas about what you would like to plant. Water lilies require at least 3 feet of water and many emergent plants only want a couple of inches. Small ponds are often constructed with a deep pocket or hole for planting water lilies. One or two plant shelves at different depths will accommodate most marginal plants. There are four basic kinds of water garden ponds. There is the natural looking one that is constructed out of the existing landscape and usually lined with clay. There is a concrete pond that can either be in the ground, partially out of the ground or totally above the ground. There is the insert type where a preformed shape is buried in the ground either partially or completely. There is the vinyl lined pond which is one of the easiest to construct and probably the least expensive, depending on size. The natural pond is the largest form of a water garden. It often requires heavy equipment for its construction. A source of water for a pond of this size is probably the most important consideration and they often can be formed by damning existing streams. They can also be fed by natural springs and possibly well water. Many features such as water falls or flowing streams can easily be incorporated into the design. These ponds can offer the greatest possibilities for plantings, both in and out of the water. Because of their size the construction is best left to a professional contractor. To seal the pond bentonite is incorporated into the subsoil. When it is moistened it will swell to many times its normal particle size and seal the porosity and permeability of the underlying soil. The concrete pond used to be the most common kind of construction. If both the bottom and sides of the pond are to be made out of concrete it will be necessary to cast it all in a single day. The bottom is poured first along with plant shelves that are included in the design and reinforcement bars are added to tie the sides or walls together with the bottom. As soon as the concrete begins to set forms are placed and the sides are poured. It takes about 28 days for the concrete to cure sufficiently for use. Its hardness can be improved by keeping it moistened during this period, usually with wet canvas or a light mist of water. Concrete ponds do not have to have cast sides. Once the bottom is poured and set concrete blocks can be used to build a vertical wall around the edge. As it is being constructed the holes in the blocks are filled with concrete making an impenetrable barrier. The wall can be back filled with cast concrete or a combination of vinyl lining and soil. As grade level is achieved the block is topped with a capping stone or other material. The concrete pond will also have to be ‘seasoned’ before any fish or plants can be added. There are a number of different methods. The surface can be scrubbed and soaked using potassium permanganate. Use extra caution with this method because the material is poisonous. Another method of neutralizing the concrete is to fill the pond with water and acetic acid which can be added in the form of vinegar. This may have to be repeated to completely neutralize the natural alkalinity of the concrete. The pond can also be seasoned simply by using water. It will need to be filled, emptied, and refilled several times. The alkalinity can be checked using simple methods like litmus paper or swimming pool testing kits. The pH of the water of a fully seasoned concrete pond should be as close as possible to 7.0 or neutral. There is a wide range of preformed pond liners ranging from the common stock tank to plastic liners specifically manufactured for ponds. Regular or geometric shapes are easy to deal with because you can flip them upside down and outlining the shape on the ground before digging. Irregular shapes may have to be fitted by an almost trial and error method to assure a solid foundation. Installing a preformed liner will require an extra couple of inches of excavation on the bottom and sides. Before the liner is finally set you will need to cover the bottom with one or two inches of sand to protect the liner from uneven stresses. After the liner is set you will need to back fill with sand to assure even support of the sides or walls. Flexible vinyl (polyvinyl chloride, PVC) liners are being more frequently used because of the reduced expense, design flexibility, and ease of installation. Butyl (ethylene propylene diene monomer) sheathing is also used and it is often mistakenly referred to as a vinyl liner. Butyl is slightly more expensive and flexible than vinyl and it is more resistant to ultra violet rays from the sun. Life expectancy of both materials can vary. Statistical information is readily available from the manufacturer and should be checked for life expectancy. Ponds can be designed to be totally in ground, partially above ground, or totally above ground. Planting shelves are easily incorporated into the design but water lily holes are difficult. Steep wall designs should be adjusted to a slope to avoid collapse of the wall. Estimating the amount of material needed in construction should take into consideration a 12 inch overlap above water level, the distance down both sides, along with the distance across the bottom and a slight consideration for variations in the calculations and excavation. The excavation of a totally in-ground pond design can be underlayed with old, used carpeting to prevent puncturing the liner by sharp rocks or sticks. Partially above ground ponds are easily built using a retaining wall to support the liner. It can be constructed out of concrete blocks faced with stone or any number of other materials. Totally above ground ponds will require fairly substantial support in the walls in order to resist the outward thrust of the water weight. The totally above ground design generally lends itself to a more formal geometric shape. The above ground design can also be used as a second level for planting or act as a biological filter for an existing in-ground pond. For lesson plans about water gardening Click here: AOL Search results for "sedge poisons" |