LITFM is your weekly guide to the world of organic gardening practices. It is our goal to make gardening accessible for all while promoting good land stewardship and sustainable practices by providing honest and balanced information backed by verifiable scientific fact.
Tuesday, March 5, 2013
Urbanite the stuff of...oh nevermind!
Welcome back to another episode of lost in the farmer’s
market! As you can see we are getting closer to the wonders of spring and the
delightful harvests of summer. Outside the birds are back as scores of
sparrows, catbirds, cardinals, thrashers and, robins are out singing their little
heads off. As for you the gardener you have heard me talk about seed catalogs
and planning and well I think I sort of beat those topics to death.Today’s topic is a wild card that came up
while out on a work site this week.
Today’s topic is “Urbanite” and no, this is not a country
term for a city dweller. Urbanite is a residual byproduct of urban development
and is commonly available for free where ever construction is going on. In
short the material called Urbanite is really scrap cement from sidewalks and
foundations, its cheap durable and no harder to use then field stone. I
admittedly have no idea who first came up with the term “urbanite” but I do
know that it is a catchy term that sounds much better then ‘scrap cement’. Plus
I can imagine if one were driving about town in a pickup truck looking for
areas to “quarry” urbanite it probably would not be that hard to find. New
construction or refurbishments of buildings or even the replacement of a
sidewalk can provide a lot of urbanite. I have to state that of course as with
any salvage item you should ask permission before hauling anything off.
I realize that some of you out there may be thinking we’ve
gone bonkers at LITFM with the urbanite suggestion. Others might be flat out
thinking something like the following.
“Eww its busted cement
why would I use that?!”
The obvious answer is the cost of stone and brick. For note
a ton of ‘black forest’ field stone costs between $150 and $200. A single band
of Pinehurst type bricks at retail level will easily run you a little below or
above a hundred dollars. When I say castle block typically used to make
retaining walls isn’t cheap, I mean it. Honestly shelling out two to three
dollars per 22 pound castle block and knowing you will need at least three
concourses means you will be digging deep in your pockets.
I might add I am no
fan of impermeable surfaces such as pavement but since concrete is generally a
mix of sand, gravel, lime and a major sticking agent it is actually
semi-permeable.Since Urbanite is
semi-permeable, this means it can aid in moisture retention, and since it’s
essentially artificial sand stone it could aid in keeping the soil warm. There
is also the chance that if the urbanite you use was made with lime as it
weathers it may help in countering acidic soil Ph.
This is the naturally occurring form of urbanite.
That aside I won’t sit up here and say that urbanite is the
wonder material of tomorrow as it has its difficulties. As you can see in the
above picture, the urbanite pieces are quite variable in size and shape. The
below picture depicts a retaining wall-raised garden bed combination is made of
irregular pieces of urbanite some of which are four to six inches thick. This
leads to a clear observation of the first and second natures of urbanite, the
pieces are often irregularly shaped, and may be rather heavy. Even so, the
above urbanite was used to make the below retaining wall. Now that’s not bad, we have a curved retaining wall that is
relatively pet-proof due to height and can be cultivated to add to existing
Stacked Urbanite can make for interesting raised beds.
A major use of Urbanite can be found at the link above. That
link goes to the web log of the Suburban Hermit of Fayetteville.Look closely at the walls used to make his
terraces, that’s finely lain urbanite but you wouldn’t be able to tell if you
didn’t see it in person. It looks comparable to the finest dry laid field stone
walls. Quite literally that is the best case scenario, think of how much
urbanite is not in a dump somewhere because he turned a waste byproduct into a
functional material.I might add that
you too could do this; it would only take some initiative and a source of
Now I have to make some observations about the two
demonstrated uses of urbanite. In the first example the retaining wall has
visible amounts of tumblehome; as the bottom is visibly wider then the top.
This design aspect is common in load-bearing walls because it spreads out the
weight of the earth behind the wall and any water weight across a greater
surface area.Additionally the slope,
height and curvature serves both to stop soil erosion, create a micro-climate
and it happens to be pet proofed.
In the case of the Hermit’s work, his contoured urbanite
walls are part of a cleverly designed and complex integrated terracing system.
The core of what he did is to negate a bare slope with little in the way making
this potential terraced backyard garden utopia. If you looked at his blog
photos you can see he crew all kinds of cool stuff very successfully. This
means that both his terracing is wildly successful but also his accompanying
plant selections approved of his design and rewarded his efforts with serious
In short we are both combating erosion with the same
material. Our style of construction and the reasons for why we built what we
built are as different as the environments we built them in. In the end the
Urbanite walls are unique, functional and work in different environments, and
only you can determine which approach is best for you.This brings us to the end of today’s episode
and I might note that you can always contact myself via this blog, the Suburban
Hermit of Fayetteville through his blogor the meetup.org group Sustainable Neighbors on their meetup page about
anything pertaining to urbanite.