Tuesday, August 17, 2010

Backyard Ponds And Water Gardens

Backyard Ponds And Water Gardens

Water adds another dimension to a garden. How to choose a site for a pond, construction materials, aquatic plants, etc. Incorporating a water garden into your landscape may seem overwhelming at first. There are several key points to think about. Is the site you’re considering more conducive to a formal or informal pond? A property with a wooded setting and rustic house is perfect for natural looking pools. These have irregular shapes and are often edged with natural stone, softened by ferns and other natural-looking streamside plantings. A formal water feature is more architectural and might take the form of a reflecting pool, with clean lines and a rectangular shape.

Generally a pond looks most natural in a low but relatively level spot, where water would tend to accumulate on its own. A spot with some natural elevation can be ideal for realistic waterfalls that splash downhill. Perhaps most important of all in choosing a pond site: don’t forget to consider how you will get electricity (for pumps) and water (for filling and topping off as it evaporates) to the pond.

Types of Installations
Here’s an overview of the three most popular pond construction methods.

Flexible PVC liners.
Polyvinyl chloride (PVC) is available in several thicknesses. Choose a minimum thickness of 20 mil for long-lasting construction. Buying the PVC from a garden center or pond supply company will ensure that it has not been treated with any chemicals that will be toxic to plants or fish (as some materials meant for swimming pool use may have been). Basically the PVC liner is laid out on a bed of moist sand at the bottom of the excavated site. The edges of the liner are concealed with stone or brick and the excess cut away. The lifespan of 20 mil PVC is about ten years. It can deteriorate more rapidly if exposed constantly to direct sunlight, so keep your pond well filled.

Prefabricated pools.
These black plastic shells resemble children’s wading pools to some extent. They are much more expensive than flexible liners but are more durable and resistant to punctures. On sloping ground, a prefabricated pool may be easier to work with. Another use is for raised pools the unit is set on top of a patio or other level space and brick or stacked stone is built up to conceal the edges. Many shapes and dimensions are available, including formal and informal, large and small. The selection, however, will always be more limiting than a flexible liner. Installation may be a bit trickier because the excavated site must very closely fit the shell.

A pool of concrete is durable and made to last --but hard to remove if you wish to ever decide to alter your landscape, to accommodate a children’s playset for example. Depending on how it is shaped and edged, a concrete pool can be formal or informal. It’s easy enough to install a drain in the bottom of the pond, or to do tilework on the bottom, sides, or top edges. Concrete must be mixed and reinforced properly to avoid settling or cracking, so it may be preferable to contract out this kind of job.

Aquatic Plants
The water lily is the most well known, and perhaps most admired, of the aquatic plants. Many varieties are tropical and must be treated as annuals, but there are also a large number of hardy varieties. In garden pools, water lilies are grown in containers of topsoil that set on the pool bottom. Pebbles on the surface of the container help to prevent the dirt from clouding the water. Most lilies need full sun -- eight to twelve hours a day -- to bloom.

The spectacular lotus is also a well known water flower. Leaves may measure two feet across. Blossoms are huge, very fragrant and rise several feet out of the water, creating quite a show. Miniature cultivars are more suitable for small ponds.

Marginal plants are a category of plants that grow in the boggy ground or shallow water at the edges of the pond. They are characterized by roots that grow in the soil. Examples include cattails, Chinese water chestnut, horsetail grass, marsh marigold, pickerel rush and several varieties of iris.

Floating plants are those that don’t need soil. Their leaves and flowers literally float on the pond surface while roots hang into the water. Best known of this category is the beautiful water hyacinth, with its lavender flowers. The yellow water poppy is another choice.

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