DIY / Urban agriculture

dirt vs soil

"Dirt" is what you scrape off your shoes 
"Soil" is what you plant in 
     -- @DSAldridge

One topic I’m passionate about is soil health, because as I’ve learned in class and from personal experience again and again and again: Soil is such a key part of growing!  I obviously can’t cover every aspect of soil health, structure and importance in one post, but today I just want to get everyone considering their soil and thinking outside the box (or inside the containers LoL)  As you can see from Eric Sloane‘s illustration below, our soil is suffering compared to a century ago.  I find this especially true with the urban plots that I work in, where years of subdivision or commercial development have razed and leveled the landscape then intentionally compacted the soil for quick easy mass construction.

american yesterday eric sloane 2Simple DIY Soil Classification at Home

One way to do a quick classification of your home garden soil is the “squeeze test” — Dig a small handful of garden soil and squeeze it firmly.  If it holds shape until being touched but then crumbles lightly you have a loamy soil, which holds water and nutrients well but doesn’t remain waterlogged for long.  If it holds shape stiffly and does not come apart easily, you have clay soil, which is nutrient rich but slow draining.  If it falls apart as soon as you open your hand, refusing to hold together, you have sandy soil, which is quick draining but doesn’t retain nutrients or moisture very well.

understanding your soil is the first step to knowing what & how to feed it

The next step after a squeeze test is the mason jar test, which will help you determine the amount or ratio of sand, loam or clay that your soil contains.  Fill a mason jar 1/3 full with a soil sample from your garden.  Try to fill a few different jars with samples from different areas and depths.  Fill the remaining space in the jar with water, close the lid and shake vigorously, then let the jars sit for 12 – 24 hours.  You will see layers of different substrates forming as the different soils settle.  Sand is heaviest and will sink to the bottom, silty loam will settle in the middle layer and fine clay particles will form the top layer.  Organic and woody pieces will likely float in the water.  The relative size of each layer will give you a rough idea of the composition i.e. 80% sand : 10% loam : 10% clay or 30:30:30 etc

What is my soil like?

A good gardener can make soil out of dirt -- @GreenSoil

The raised beds I work with are filled with (donated) Big Yellow Bag black loamy soil, top dressed with 1″ of compost or manure each spring / fall and they cover the natural earthen Niagara clay.  I have also amended soil on some of my properties with Myke mycorrhizal supplements, Gro4 worm castings, and home-concocted compost teas to increase microbes in the soil.

In my greenhouse containers I use a specialized blend of potting soil.  Outdoor soil tends to be too heavy, it compacts and get waterlogged in containers, I’ve also learned the hard way that moving soil from outdoors to indoors is likely to bring along contaminants such as pests, fungi and diseases.  In my larger production greenhouse containers I use Berger BM6, primarily because that’s what my college’s greenhouse uses, and I purchase my bales of soil through them.  But in my smaller home greenhouse and indoor growing areas, I mix my own container soil — primarily peat moss with perlite, vermiculite, sand, compost, or other amendments added as needed specifically by each plant.  I add a differently calibrated indoor-specific mixture of Myke mycorrhizal supplements, Gro4 worm castings and I fertigate daily with a much weaker brewed compost tea.

a sample “soil recipe”

Succulent Potting Mix
(also works for Cacti)
parts builders sand
1 part perlite
1 part potting soil
1 part peat moss


One thought on “dirt vs soil

  1. Pingback: Feed the Soil, Soil Feeds Plants, Plants Feed You

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