While all of this talk of storm water management may sound rather complicated, and possibly a bit overwhelming to the budding gardener (excuse the garden pun), it really is not. It is the purpose of the rain garden to mimic the effects of a forest. Nature handles down pours of water with the interaction of plants rather than storm drains. Picture a forested area as you plan your rain garden. Work to create a multi-layered ecosystem that includes a tree or trees, where space will allow, and an understory of deep rooting shrubs and perennials.
Plantings provide mechanisms for the water to be dispersed back into the air through leaves and branches which reduce impact on the ground. In turn, this facilitates assimilation and filtration of water into the ground with the help of the plants root systems. Most experts will recommend the use of native plants because they will generally adapt well to local site conditions. They are also more likely to be a better food source for local birds, insects, and other wildlife.
Choosing an appropriate site for the garden is of critical importance. Always remember that it is the goal of the rain garden is to filter and slow down storm water runoff. The most likely source of runoff will be roofs, lawns (which are shallow rooting and provide minimum runoff absorption), driveways and roads.
Ideally the garden will be located in a spot that is low by comparison to the majority of the property. If the desired location is on a steep slope additional excavation will be required to create the shallow bowl type shape that is necessary for a successful garden. It is also recommended that rain gardens specifically focused on managing run off from roofs should be located at least 10 feet from the drip line of the roof.
All images Roberta Bogash
Water should drain from the site within a 72 hour period or the soil on the site should be amended to assist with better drainage. There are several on-line sites that provide further information on how to test for the appropriateness of the garden location. Make sure the information that is used is specific to the region where the garden will be planted.
- Choosing Plants for your Rain Garden will be posted soon.
