Soil solutions: dealing with clay

Clay soil can be hard work for plant roots, but there are ways to improve it.

Soil comes in many different variations so simple soil solutions that cater to each type are handy to have. Here we look at clay soil.

Clay soil

Clay soil is usually silky smooth to the touch and does a great job of retaining nutrients. However, it drains poorly and eventually dries into hard, compacted soil. It is hard work for plant roots and back breaking for gardeners to dig.

Fixes: Add organic matter and plenty of it! Compost, manure and fine mulches should be applied regularly and over time they will improve the soil structure. Raising up garden beds using the no-dig method is another way to create a perfect growing zone above the clay.
Gypsum can also help ‘break up’ clay soils but does not work for all types. To test your soil, drop a clod into a jar of water and wait 2 hours. If the water turns cloudy you have dispersing clay, which responds well to gypsum. If the clod breaks apart, without clouding the water, you have slaking clay and gypsum is not very effective.

Plants to the rescue

Improving difficult soil is often a slow process and sometimes not practical. Rather than give up on gardening, the answer is to find plants that are well suited to the soil conditions. For heavy clay soils try: daylilies, mock orange and jacaranda or natives like lomandra, scaevola and Callistemon viminalis.

For Steve Falcioni’s full article with solutions for troublesome soils get a copy of our Spring 2025 issue (OG 160), available from selected newsagents or supermarkets. You can also subscribe and get the magazine delivered to your door.