Even if you were paying really good attention in your Geology 101 class, you probably haven’t heard of urbanite. It comes in almost any color you can imagine, sits conveniently on the earth’s surface waiting to be loaded on a truck, and is as hard as concrete.

That’s cuz it IS concrete—recycled slabs of pavement seeking a second career. It makes sense to put such a durable and multi-use material back to work, instead of dumping it into landfills, then mining and manufacturing more.

Urbanite has lots of uses in the garden, as I was reminded on my Open Days garden tour in Pasadena last month [read my April 29 article]. If you can build something with flagstone, you can generally substitute urbanite at a much reduced cost. It’s free, since scrap concrete is usually seen as a waste product that has to be disposed of. Most of the expense is in short-distance transportation and labor for installation. Better yet, if the concrete is from your former cracked driveway or patio, you can even scratch the cost of loading and transport.

Artful Uses

Urbanite was artfully used by designer Mark Rios, in the 1996 and 2002 garden restoration at Ann and Peter Murphy’s 1906 Mission-style home. I noticed the recycled concrete as I stepped off the front porch and passed under the cool shade of crape myrtle (Lagerstroemia indica) trees that flanked the walkway. The path leading to the south side of the garden was a visual contradiction, running gun-barrel straight while made up of randomly-shaped pieces. Notice how the outer edges form strong parallel lines, while the inner pieces appear to dance around. path
     
At the north side of the house was another, less formal use of large slabs, softened with a simple understory of shade-loving baby tears (Soleirolia soleirolii – say that fast three times).   path


I caught some strange glances from my fellow garden photographers as I crawled on the ground, focusing my camera on slabs of lowly concrete, while they stampeded to the rose garden. But in my book, this little wall is really a work of art, reflecting the skill and aesthetics of an experienced stone mason. The first thing they had going for them was the seriously hefty pieces they had to work with—the thicker the concrete, the more “gravitas” it has, with the durable look of real stone.
wall

Notice how the top slab slightly overhangs the others, creating a shadow line like the capstone of classic stone walls. There’s also a rhythm to the size and spacing of the blocks that creates a sense of order.
I looked across the back yard and had to smile: A pair of recycled concrete plinths stood guard at the flanks of a broad set of urbanite steps. Small pieces were used as unmortared bricks and new square slabs provided contrast. I’m not smitten by the final results, but I appreciate the imagination that went into it. plinth

How To

When working with recycled concrete, respect it and work smart.

  • Starting with the “well, duh!” category, the stuff is heavy and depending how it was removed from its original home, it can have edges sharp enough to give you a nasty cut.
  • Wear protective gear—steel-toed or at least heavy-duty construction boots; tough, but flexible gloves and eye protection if you’ll be saw-cutting or chiseling to refine the shapes.
  • Lift smart—legs, not back.
  • Read up on stone masonry techniques for design ideas and construction methods.

As for my earlier claim that urbanite comes in lots of colors, it’s pretty obvious from those stubborn oil stains on your garage floor that concrete is a very porous material. It absorbs water-based, environmentally safe wood stains applied by brush, roller or airless sprayer. There are also concrete-specific chemical stains available from Bomanite and others. To make your recycled concrete look less like actual concrete, consider a color similar to the natural rock in your area.

There’s really nothing more sustainable than pulling material from the waste stream and getting another few decades (maybe centuries) from it. Your only limitation is your imagination.

NOTE: My previous blog post gave you a behind the scenes look at some gorgeous public-for-a-day Pasadena gardens. The Garden Conservancy’s Open Days Tours are a great way to gather ideas for your own landscape, helping to preserve important gardens around the country, and spending a few fantasy-filled hours seeing how other people garden. If this sounds enticing to you, check their schedule. Open Days tours run through October.

For a virtual tour of the gardens, click on this Los Angeles Times article.

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