Tuesday, January 6, 2009

Sustainable Sites

After reading through the LEED manual, it was apparent we needed to eliminate all turf and use all drought tolerant native grasses and perennials. We could 'build' a meadow! How 'green' is that?

First inspiration was drawn from Oehme van Sweden's 'designed meadow' style and the cost of installing a meadow was researched. When presented at our next team meeting this solution proved to be too expensive. In order to have a successful meadow, you must plant the grasses and perennials quite close to keep the invasive species from germinating and overpowering the native species. Invasives choke out the native species since they grow faster and larger. The quantity of materials needed blew the budget. A disappointment for everyone.

So back to the drawing board.....what would be more cost efficient? Ah ha! What if we let the site go back to its natural state - a woodland/forest? There are plenty of dormant seeds in the soil as well as ones delivered by the wind and birds. This would take patience to develop and constant maintenance to control the invasives that geminated but it is an inexpensive and progressive solution. When presented to the team, everyone agreed it is a perfect solution for this project.

And as it turns out, the woodland/forest is one of the owners' favorite landscapes.

The original plant communities of this area are of two types: Midslope Forest and Mesic Forest.

The species in the first type are dominated by White Oak, Post Oak, Southern Red Oak, Pignut Hickory with understory trees such as Dogwood, Sourwood, Blackgum, and American Holly. The shrubs include low various blueberries, dwarf Paw Paw and Strawberry bush.

The second type, Mesic Forest, has many of the same canopy species but the notable presence of the American Beech, Tulip Poplar and Northern Red Oak dominate. The shrub layer includes Wild Hydrangea, Piedmont Azaleas and Musclewood.

Now how to get there?? Our first step to re-create the woodland/forest is to build a rich organic soil 'floor'. We will accomplish this by simply covering the bare areas with clean wood chips, leave it for a year or two and remove the invasives as they appear. The only plantings we are specifying now are going to cover any of the steep slopes to prevent erosion and use only native shrubs and grasses.

First piece of the puzzle solved! On to the next ones......

- Lynn Saussy, Landscape Architect

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