ISSUE 32  |  Modern Glamour

Hardscaping 101: Seashell Surfaces (Paths, Driveways, and Bocce Courts)

August 18, 2016 6:00 AM

BY Janet Hall

We think crushed seashells should be on the short list for topping paths and driveways. After all, they’re natural, beautiful, functional, and remind us of the sea. Read on to find out if crushed seashell is the best hardscaping material for you.

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Above: A clamshell driveway in Maine in a garden designed by landscape architect Matthew Cunningham. Photograph by Matthew Cunningham.

Shells are used as a paving material all over the world. In the US, seashell paths originated in Colonial times as a result of early-American recycling efforts. Oysters and other shellfish were a primary source of food, and thrifty settlers put their discarded shells to use as a paving material. Later, this practice became common in New England as a way to recycle waste from the seafood industry.

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Above: Photograph by Justine Hand. After a seafood meal, real Cape Codders throw any and all shells into their drives.

Why use seashells to cover paths and driveways?

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Above: A shell path in a kitchen garden at Colonial Williamsburg. Photograph by Justine Hand.

A great alternative to gravel, crushed shells can be used on paths, patios, courtyards, driveways, and even bocce ball courts (the shells don’t hold water or imprints from shoes and balls). As the shells are walked on or driven over, they break into smaller pieces that disperse evenly, creating a stable surface that’s not prone to the ruts and holes you get with crushed stone toppings.

Another benefit is that, as long as they come from a sustainable harvesting operation, shells are environmentally friendly. They provide excellent drainage, since rainwater runs through them to percolate into the ground. And shells are a natural material that benefits the ground below as they decompose.

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Above: The crushed-shell driveway of Jonathan Adler and Simon Doonan’s Shelter Island home. Edging the driveway are a pair of autumn olives and tufts of drought-tolerant prairie dropseed grass. Image by Vickie Cardaro.

How do you install a crushed-shell path or driveway?

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Above: A path of shells leads to the shore in Maine in a garden designed by landscape architect Matthew Cunningham. Photograph by Matthew Cunningham.

Coverage is key. The experts at Emerald Landscape Supply in Massachusetts recommend a 3-inch-deep application. Some installers suggest starting with a gravel base, but it must be compacted and leveled (preferably by a professional) so the surface doesn’t become soft. You want to ensure that tires drive over–not through–it. The shells will compact and become more stable over time.

The general rule of thumb is that one cubic yard of seashell will provide a 3-inch-deep cover for a 100-square-foot space.  Another tip: Shell hardscaping is best for level surfaces. A steep drive is not a good application, as the shells are likely to collect at the bottom.

What are the best shells to use?

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Above: Shells from Chesapeake Bay cover a path at Colonial Williamsburg. Photograph by Justine Hand.

The most common shells used for hardscaping are oyster, clam, and scallop. Their differences are subtle: mostly in color and how they break down. Oyster shells, primarily off-white and gray, break down in a way that makes them more compact and, subsequently, more stable over time. Clam shells, mostly off-white or yellow-white, are slightly more fragile and will break down faster than oyster shells. They also compact nicely for vehicle traffic. Scallop shells add brown coloration to the mix. Despite initial variations in color, all the shells bleach under the sun and become lighter over time. Your choice will most likely depend on what’s readily available in your area.

 

Don’t seashells smell?

Shells that are sold in bulk for hardscaping purposes are left over from seafood harvesting, so the shellfish have been removed. Typically, the shells have been thoroughly washed, so there should be little left to generate stink. That said, they may arrive with some natural aroma, but that should dissipate within a day or two. (To one homeowner, they smelled like the beach, not dead seafood.)

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Above: Crushed shell hardscaping isn’t limited to Cape Cod-style settings. It works well at this oceanfront house in Bridgehampton, NY, by Stelle Lomont Architects, a member of the Remodelista Design Directory. Image by Francesca Giovanelli, Kay Wettstein von Westersheimb.

How much do crushed seashell paths and driveways cost?

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Above: The edge of a seashell driveway in Maine in a garden designed by landscape architect Matthew Cunningham. Photograph by Matthew Cunningham.

When bought in bulk, seashells are on the more affordable end of the spectrum: comparable to crushed gravel; less than asphalt, concrete, or stone. Clam shells seem to be the least expensive, offered at about $40 per cubic yard, or $50 per ton. We priced crushed oyster shell at $385 per ton. The Atlantic coast is the primary source of shells; if you live elsewhere, shipping may be the most expensive part of the project. Contact your local landscape supplier for availability. Alternatively, suppliers like Myco ship crushed shell all over North America.

Buyers tip: Buy in bulk for the lowest price. Unless you’re covering a very small area, avoid purchasing small bags at a feed store or the like.

What about maintenance?

The good news: Shell paths and driveways can’t crack, so repairs aren’t part of the package. Cold and heat won’t damage the shells, and they don’t develop ruts and holes. Assuming a generous layer was applied at the outset, the material will last a long time. Because of compacting it will eventually need replenishing, but not every year (or even every other year). And unlike gravel, crushed shell hardscaping rarely encounters issues with weeds or pests: The shells’ sharp edges act as a natural deterrent (but they’re not so sharp as to be an issue for tires or shoes).

Seashell Path and Driveway Recap:

Pros:

  • Natural product
  • Durable
  • Affordable
  • Low maintenance
  • Light colors mean cooler surface in hot climates
  • Provides excellent drainage and prevents runoff
  • Visually appealing
  • Won’t crack or break, requiring repairs

Cons:

  • Rough surface that is not barefoot friendly or conducive to bikes, trikes, and other smooth-surface toys and activities
  • Not a good covering for steep drives or paths
  • Snow removal difficult
  • Not readily available in all areas, and shipping may be expensive

For more ways to use shells in a landscape, see Garden Visit: Secrets from an Earlier Century at Colonial Williamsburg and Landscape Architect Visit: Clamshell Alley on the Coast of Maine.