An annual DIY Soil Test

living soil looks like this edible backyard nz

Your soil is unique. It’s history and geography make it so.

And because it’s unique, and because understanding your soil is at the heart of your garden’s health – you do well to get to know it. To know what it feels like, what it smells like, how many critters live in it, how well it holds water… all about it! The best way to know it, is to test it. Yourself! With your very own eyes and hands and nose.

There are 2 DIY soil tests I hope to inspire you to incorporate into your gardening life:

The goal of this test is to get to know all the different parts of your land – the high bit, the low bit, the shady bit, the flat bit – so you can make sound decisions as to what to plant and where to plant it. Test each area, at about the same time each year to see how the soil is responding to your guardianship. Spring is my preferred time.

Record your findings in a notebook. This record is so blimmin useful. It will help you manage your soil, and if you need lab tests at any stage – you’ll be able to speak to your soil with authority. If you are starting a garden, note your initial findings on your basemap.

How to do an annual soil test

This test is simple observing – nothing tricky! Note down your observations, and you’re on your way.

Dig up a square of soil that’s a spade by spade wide and a spade deep.

  • Lay the square of soil on a bit of cardboard (or some such). Use your fingers to break the clod up. How easily does it come apart? What size crumb does it break into? What are the roots like – branched, narrow, dreadlocks (those are the best ones).
  • Count the worms before they wriggle away. Don’t worry if all you find is 2, my first ever worm count in the orchard revealed 0!, but year on year as the soil improved, they came. Same will happen for you.
  • Grab a handful and take a good sniff – smell tells you alot. Sour means air and life are absent, musty means low organic matter and not much life (apart from maybe slaters!). Earthy and good, is where you are headed.
  • Squeeze the same handful of soil together, then open your hand out with a little shake. Good growing soil will loosely stick together in a few clumps with a few crumbs that fall away. Poor growing soil will either slip through your fingers with nothing much sticking together (sandy) or will stay moulded, retaining the shape of your fingers (clay).
  • Look into the hole and take a photo – there’s lots of good intel down here!
    Look at the roots – the deeper the roots, and the more tangled and branched they are, the better your soil.
    Look for air pockets, worm holes, critter holes
    Note layers – topsoil, subsoil, gravel, rock, clay…
    Note the different colours. The NZ soils map or the regional soil descriptions on are an interesting look up. Your local council may have good local soil resources too.

I cannot enthuse enough as to how satisfying and useful it is, to connect to your soil. To be so connected that as you walk around your land you’re not only seeing what’s on top, but knowing what’s beneath.

When you understand where your soil is at and that it is slowly evolving, you aren’t bothered when things don’t grow so well.

This tie to your soil, this knowing, is peace of mind. It’s the heart of the food gardener.


  1. Susan McCardle says

    Hi Kath, I made the mistake of putting torn foxglove leaves into my veggie patch when I was planting new seedlings thinking that it was comfrey.
    Would you know if I have made the soil toxic now from doing this?
    Many thanks