Making garden space from compacted soil.

By Patricia Beynan

Our community garden members chose to either make raised beds and fill them with topsoil, compost, and peat moss,  or to dig out the compacted soil to a depth of  about 18 inches, sift the soil that was removed, breaking up the clay, and mixing it with compost and peat moss.  The garden managers kindly provided a a few loads of compost from Fairmont Park for our use, available from a big pile at the edge of the garden.

I found both options daunting.  I was on my own in creating the 12 x 12 garden from soil that had been paved over for nearly 100 years.  It was not only compacted to rock solid status, but it also was covered with the gravel layer that had been under the asphalt and chunks of the newly removed asphalt.  The garden steering committee offered help and advice, and provided giant screens to use for sifting.  

The dig out option involved the pick and shovel approach, and the raised beds were a building project.   I wanted another option, and as I was removing the top layer of chunks, and watching the pick and shovel folks strain and groan I decided I would find some middle ground.  After the asphalt was gone I imperfectly raked the gravel to the edges to make paths between my plot and the neighbors.  I decided the remaining gravel was good for drainage, and started wheelbarrowing in compost.  Over the course of several sessions I brought about 15 loads over from the rapidly diminishing pile.  I raked that into the top layer the gravel clay surface and decided I could work with that.  

I got a few more loads of compost and dumped them at one end of my plot.  Now it was time to plant.  I had three kinds of  lettuce, red and green cabbage,  eggplant, peppers and tomatoes in little pots, and cucumber, peas, cantaloupe, carrots, and green beans in seeds.  My plan evolved as I worked.  I dug through the compost layer, then put the hose on the clay for a minute, making an instant pond.  After it soaked in I dug out about eight inches, mixed that clay with the compost, put half back in, then my seedling, then more of the mix, tamping it down.  The improved area was only about 6 inches in diameter. Would it work?

Worked like a charm.  I could barely keep up with the output of my spot amended soil.  Everything flourished, and my only failure was cantaloupe, but that may have had more to do with the monsoons of August than the soil.  

This year I'm adding more compost, digging new holes to spot amend, and rotating the plant locations.  I have high hopes.