Cosby Courtyard Renovation

Cosby Courtyard Renovation

Photo credit: C. SawyersLast summer the lawn area of Cosby Courtyard underwent a transformation. This area had become a major thoroughfare for pedestrian traffic as it provided a direct path from the northern academic and parking areas of campus to Parrish Hall where Admissions, the Post Office, student residential rooms, and other offices are located.  Since it had become a losing battle to try to maintain turf in this area, and we did not want to add another impervious surface to the campus, we opted for using a product called “Stabilized Grey Mountain Gravel” from GreenPro Materials in Bound Brook, New York. It is crushed gravel to which Stabilizer® powder has been added. Stabilizer® is a patented, organic, and non-toxic soil binder. The main component of the blend is manufactured from the seed hulls of the Plantago ovata, commonly called psyllium or Indian plantago. When used with the crushed gravel, this product does not change the aesthetic or permeable characteristics of paths and patios – it remains porous and reabsorbs minimal water. Stabilizer® helps to keep the material in place, make a firm walking surface, reduce maintenance, and improve safety and accessibility.

Photo credit: C. Sawyers

To replace the lawn in Cosby Courtyard, the irrigation system was removed and the area excavated.  Over the compacted subgrade, four inches of drainage gravel were added.  Next, the dry “Stabilized Grey Mountain Gravel” was put down.  After being thoroughly wetted, the product was compacted with a roller. Once dry, the product was ready for use.

This renovation project provided an opportunity for the Arboretum consolidate the artful display of container plantings. The big copper urn that had been tucked into the black bamboo, Phyllostachys nigra, was moved out onto the gravel as were several other containers. This allowed for a spectacular display of late summer plant combinations and a prominent area for the wonderful winter containers.  In addition to providing beauty and interest, the containers also help direct foot traffic through the area.

Photo credit: C. Sawyers

Although not a consideration for the renovation in Cosby, using “Stabilized Grey Mountain Gravel” could provide for up to five Leadership in Energy and Environmental Design (LEED) points in the categories of stormwater management (2 points), reduction of heat island effect (2 points), and use of local/regional material (1 point).

“Stabilized Grey Mountain Gravel” is also being installed at the south entrance slope to the Scott Amphitheater as part of a project to improve accessibility into the Amphitheater.

Sue Stark
sstark1@swarthmore.edu
2 Comments
  • shane morgan
    Posted at 18:20h, 03 April Reply

    The courtyard looks great! Do you have any other information about the the stabilized gravel? How much it costs per square foot? and is it only available for commercial applications? I design residential gardens and have a client who may be interested in this. Thanks for any extra information you may have.

  • Sue
    Posted at 13:29h, 08 April Reply

    Hi Shane,

    We got our stabalized gravel from GreenPro Materials:

    Div. of Tri-State Materials LLC
    P.O. Box 265
    Bound Brook, NJ 08805
    (P) 908-647-0159
    (F) 908-647-0835.

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