How to Transform Heavy Clay

Winter is a telling time in your soil health journey – from now through early spring you get to see your drainage in action. Those of you at the basemap phase of gathering info and learning your land – perk your ears on up! How wet are your soils?

Drainage is absolutely key for plant health. Our edible gardens must have oxygenated soil to be at peak performance. Water displaces air, you see, so if your soil is soggy, it is also airless. It’ll feel heavy, sticky, be pale or grey-ish in colour and most likely be sour smelling. Soil life thumbs it’s nose at conditions such as these, and herein lies the deep reason for the drainage – without soil life, there cannot be above ground abundance.

There are, of course, degrees of wetness. From vegie patches that are underwater for long periods – a loud cry for drainage to be resolved, to soil that’s simply a heavy clay – awaiting transformation to a delicious vegie-growing loam.

Transforming heavy clay

Start by doing this simple drainage test. It’s great to do this when soils are at their wettest so you can understand your worst case scenario and shape your land to cope with it.

If your drainage gets the gold star, but your soil is heavy and wet at this time of year – take heart!, its simpler than you think to transform it. You will, one winter not too far away, be able to plant and sow.

Meantime, sticky clay should be left well alone – like a grouchy teenager, playing with it in this state only makes it worse. Cover it with lots of mulch for now and grow your crops elsewhere in containers.

Once the soil’s dried out (no puddles, no sound effects)

• Lightly sprinkle on gypsum to help break up the clay.
• Wield your forksta or garden fork, and aerate the ground.

On top of grass + cruisy annual weeds

• The slow but best way, is to lay wet cardboard, then build a compost pile on the spot and leave it to rot down. While you wait, grow in containers. Get in a rhythm of making a new compost bed every month or so and before you know it, you’ve created a whole garden on homemade compost. Yuss! Best fertility ever…. youre on your way to Eden.
• The instant way – cover the ground in thick, wet newspaper or wet cardboard and spread about 15cm of compost on top. If buying it in, work out how many cubic metres you need with this math – length of area x width of area x 150mm (or however high you are going).   

On top of existing garden beds

• If the beds are weedy with grass and gentle annuals, slash them back, leaving the debris in situ, then lay wet newspaper and spread compost.

When using bought compost, my go to first crop is always a greencrop, to settle the compost in. Nothing calls out to microbes like a bunch of roots – sugar exchange a go! Then before planting out the first vegies, you could if you have it on hand, saturate the soil in a biological brew or good old seaweed or fish.

Drive the transformation home

The reason your clay holds water so, is that it is made up of very small particles. There’s no room for air down there – perfect for hanging onto water! By regularly adding organic matter, you’ll alter this tiny particle situation, joining them together bringing space and in this space along comes biology, and humus – the glue of life.

• Never leave your soil bare – keep it covered with crops, greencrops or a homemade nourishing mulch. Top this up as often as needed.
• Use greencrops often – either as living mulches, or before heavy feeders, or to fill the gap when you run out of mulch.
• Pour on a monthly liquid feed that includes EM, as often as weekly through the warmer seasons. Don’t use it once soils go below 10 degrees as life is not active in the cold.
• Trench your foodscraps or bokashi up the centre of bed when ever a heavy feeder is on the go. Such an awesome source of free fertility.
• Grow plenty of useful and gorgeous perennials (especially tap roots!) around the outside edges of the vegie garden to open soils and provide a breeding ground for soil life.

You’ll notice there is no digging in my list, nor the addition of sand. Go on top, and leave the rest of it to the soil life.

Little and often, keep at it – and as your soil improves, you’ll need to add less and less. Stay in touch with your soil regularly to keep up with the changes. This habit is at the heart of being an awesome gardener.

Soon you’ll see a change in colour and an increase in earthworms, you’ll feel a loosening of the texture, smell a sweeter smell and for the brave, the soil will loose it’s tangy taste. And above ground, all your garden dreams will be coming true cos as above, so below. 

Take heart and go the course.