Monday, March 4, 2013

Building a Rain Garden



The purpose of a rain garden is to collect rain water in a shallow depression in the yard rather than let it rush off into a storm sewer or local waterway. This area is then planted with grasses, bushes or trees that are selected because of their ability to absorb and filter storm water. A rain garden can absorb runoff and remove pollutants more efficiently than a standard lawn by capturing the rainwater, holding it for a short time and then slowly releasing it into the soil.

Members of the Fort Myers-Lee County Garden Council wanted a rain garden installed in the Berne Davis Gardens, which is on the premises of their headquarters at 2166 Virginia Avenue, off McGregor and just past the Edison Winter Estates. The existing pond which was in the garden was not adequate to handle the water accumulation during the summer rainy season. The company that designed and built the rain garden was Ensite, a local landscaping business located in Fort Myers. The accompanying photos were taken over a period of five days, between January 23 and February 19, 2013, as the rain garden was being built.
 
 
The best place for a rain garden is a naturally-occurring low spot in the yard, preferably in either partial or full sun, that receives water regularly during a rainstorm.
 
 
 

There was already a small basin in the Garden Council garden, but it didn’t begin to control the storm water accumulation from our colossal summer rainstorms. This location has a made-to-order depression in the yard in which to locate the rain garden, and the spot receives full to partial sunlight--it would seem to be an ideal spot for a rain garden.
 




Rain gardens typically work best if they are curved and slightly irregularly-shaped. The sides should slope gradually from the outside edge to the deepest area. The longest side should be perpendicular to the slope. The bottom of the rain garden should be as level as possible so that runoff water will spread evenly in the garden rather than pooling in one area. If a rain garden is no more than about 6 inches deep, storm water will usually be absorbed within a one to seven-day period. At the end of Day One, the pond with its rock border was completely removed, the turf was dug up and the basic depression and its boundaries were established.

 
The framework for a boardwalk structure was in place at the end of Day Two. The boardwalk starts at the top of the depression, curves around the gazebo, and ends at the main garden path.


Planks are laid out for the boardwalk, but the framework for the boardwalk itself has not yet been completed on either end.
 
 
A closer view of the boardwalk
 
 
The boardwalk with a view toward the central part of the garden
 
 
The framework for the boardwalk was completed by the end of Day Three.
 
 

Planks are laid out on the boardwalk.
 
 
Planks of the boardwalk were fastened into place but had not yet been cut to size. The view is toward the central part of the garden.
 
 
The brand of composite decking used on the boardwalk is “Veranda Armorgard.”
 
 

By the end of Day Four, the boardwalk framing was completed,
and three trees had been planted and staked.
 


Two of the trees are to the left of the boardwalk,
and the third tree is between the boardwalk and the gazebo.
 
 
 
Tree One
The boardwalk is at its highest point to the right of this tree.
 

Treet Two is behind Tree One and farther back in the depression.
 

Tree Three is to the right of the boardwalk, near the gazebo and the farthest back of the three trees.
 
 
 
The far end of the boardwalk, where the planks have  been shortened on either side
 
 
The far end of the boardwalk, with a view toward the central part of the garden
 
 

 
By the end of the morning of Day Five, plant materials had been set into place in their approximate positions, about 1 foot apart from each other. Native plants are best adapted to our climate and should be used for rain garden installations. The plants must also grow well in both wet and dry areas because the rain garden will temporarily fill with rainwater from time to time. Native plants generally require the least care to thrive and also tend to develop strong root systems. If plants are at least 1-2 years old, they will already have established root systems. Shrubs will generally soak up water and prevent erosion, and water-loving trees are also good in larger rain gardens.
 
 

Most, but not all, of the plants are in place beside the boardwalk.
 
 
There is a mixture of grasses and bushes to the left of the boardwalk.
 
 
The boardwalk has been completed.
The planks have been trimmed to size and caps have been placed on top of the pillars.
 
 
The completed boardwalk and plantings, with a view toward the central part of the garden.
 
 
Shell paths which lead up to and away from the boardwalk on either end have been installed.
 
 
The shell path on either end of the boardwalk joins up with the existing path through the garden.
 
 
A close view of plants near the gazebo
 
 
A view of the tree and plants to the right of the boardwalk
 

 
A view of the gazebo and plantings
 
 
By the end of Day Five, the bushes and grasses have been planted and there is a layer of pine straw mulch to help keep the moisture in and the weeds out. Heavier mulches are needed because the lighter materials may float and get carried away if overflow occurs.

 

The completed rain garden, with all of the plants in place

Once plants are well established, this garden should thrive without additional watering. Fertilizers will not be necessary, and only minimal weeding will be needed after the first summer of growth.

The garden is open to the public on Tuesdays from 10:00 AM to 1:00 PM until April 16.


Rain Garden Photographer, Becky Bodnar