Clay soil is sticky, heavy and more challenging than your regular loamy soil.  Clay soils drain slowly so can stay saturated for long periods after rain.  When clay dries, it is usually forms a cracked, hard surface.

There are benefits to a clay soil however, which are that it can hold nutrients and moisture better than other types of soil.  With a little bit of work, a clay soil can be amended to make it humus rich and fertile.

MYTH: Adding sand to a heavy clay soil will fix it. The majority of the time, this will make your ground set like cement.

pH Testing

Clay soils can be rich in nutrients but if you have the soil too alkaline or acidic, the plants won’t be able take advantage of these nutrients.  A home test kit is all you need to check whether your pH is neutral – generally between 6.3 and 6.8 is where you need to be.  If your soil is too alkaline then the addition of composts, manures or mulch will assist.  If it is too acid, then some lime, dolomite or poultry manure will help.

Organic Matter

Organic matter is one of the key ingredients in amending a clay soil.  Organic matter helps with drainage as well as adding nutrients and improving the soil’s texture.  A great source of organic matter is composted chicken manure pellets (Super Booster, Blood & Bone Plus or Super Growth).  Aged manure has the benefit of being nutrient dense and rich in organic matter.

TIP: It is important to wait until your clay soil is fairly dry before working with it so you don’t damage the structure of the soil.


Liquid Clay Breaker

An important step is using a liquid clay breaker like Super Cal, a fast-acting concentrate delivering 100% available calcium.  Just 1 litre of Super Cal is more effective than 20kg of Gypsum.  The easiest way to apply is using the supplied hose on applicator, spraying liberally over the area that needs to be treated.

Work the Soil and Add Organic Matter

It is important to wait until your clay soil is fairly dry before working with it so you don’t damage the structure of the soil.  Then get a garden fork or rotary hoe and rip the soil to de-compact it and let it aerate.

The next step is adding organic matter to the garden bed, working it into the top 4-6 inches of the soil.  Organic matter sources can be composted chicken manure products (Super Booster, Blood & Bone Plus or Super Growth). or other forms of compost, green manures, animal manures and aged lawn clippings and leaves.  These additions will help with drainage and aeration.

Improving soil can take a while! The combination of using a liquid clay breaker and then regular applications of organic matter will help you to improve the fertility and tilth of your soil over time.

TIP: Mulching garden beds over winter or whenever they are not in use will help build organic matter as the mulch breaks down with the added bonus of minimizing weed growth.