The Secret Under the Grass

One of my most puzzling memories as a child was that of an occasional Baltimore A-rabber going through the streets hawking not fruit, but Tooop-Sooooill!  Why in heaven’s name would anyone need topsoil, I wondered, looking at the manicured lawns on our street. The grass was growing in dirt, it seemed very happy (most of the time) – why sell topsoil?

Baltimore’s A-rabbers, a 150-year-old city-wide tradition nearly at its end, may get a new lease on life as a healthy source of food in poor communities.

I found the answer to that question this year. For years, I’d thought that around 15 inches below the grassline of our yard lay hard, cement-like white clay. We hit it consistently while driving in the posts for our veggie garden – hard enough that my shoulder joints ached for days afterward.

Over the years I hit it when planting small bushes, or digging the occasional grave for a beloved pet or a road-kill. It was a curious nuisance, nothing more, a peculiar layer under the thick squidgy red clay that lay a few inches beneath the grass. For years I tried planting trees and bushes with deep tap-rots to break it up – uniformly, they died. Nothing could get through that stone-like barrier.

That was before I called Eric Kelly of Charm City Farms out for a site survey and permaculture consult. He ran an impromptu “perc (percolation) test” to determine the absorption rate of the soil – digging a 12-inch hole, emptying a 5-gallon bucket of water into it, poking a long stick into the bottom, and waiting to see how fast the water drained.

Half an hour later – surprise! – the water had barely sunk an inch. We began discussing options for earthworks to capture and hold the water in the soil, moved to other areas of the property, and the hole sat there with its muddy water. By the next day, it had drained, and I decided to widen it, deepen it, and plant a fig tree in it (not a good idea – figs like well-drained dry soil, I later learned). The hole would have to be 18 inches deep by 2 feet wide…

For  examples of water-storing earthworks, and the principles
behind them, click here

IMG_20150725_184511206
Concrete blocks shore up an earth berm leading to a rain garden

I hit the “white clay” at 14 inches – except that this clay had an odd protrusion. Two sweaty, back-breaking hours and a sizeable cairn of hulking cement hunks later, I knew why the A-rabbers  sold topsoil: this wasn’t cement-like – it was cement!  The developer had evidently spread unwanted cement debris from building the foundation at grade level, then covered it over with “builder’s loam” – a euphemistic term for thick, squidgy, dead red clay – and then topped it off with a thin layer of topsoil, just deep enough to support a lawn.

Between the clay and the rubble, no wonder the lawn turned into Camp Swampy when it rained. The water never sank into the clay – instead it saturated those few inches of topsoil before sluicing across to the nearest low point it could find: my basement.

And I would wager that this was the source of my neighbors’ water problems, also……

To learn the grading rules that the developers of our neighborhood
should have followed – 
but didn’t – click here

So – now that I had my 18″ x 24″ hole, how to prevent the baby fig tree from dying a nasty death by suffocation and/or drowning in this terrible soil (where’s a good A-rabber when you need one?)? Thanks be, plenty of compost, plenty of coarse organic matter, and a good-sized bag of potting soil were on hand, perfect for layering if I blended just enough of the old soil with the potting mix to give substance without sacrificing drainage.

A pile of concrete chunks grows with every addition to the forest garden.
A pile of concrete chunks grows with every addition to the forest garden.

A few weeks later, I’d added two blueberry bushes and a peach tree to my baby backyard food forest, giving them similar treatment. A month later – just as the lawn is beginning its transition from springtime mud to late-summer hard-pan – they seem to be doing nicely. And at the bottom of the garden, a growing pile of concrete hunks offers creative potential…a rock garden? Base for a firepit?

Whatever I decide, heaven knows there’s plenty more where that came from!

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