Problem Solver: Heavy Clay Soil - Richgro
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Heavy Clay Soil


Hard to manage soils. Rich in clay particles that feel slightly sticky and dense. It is smooth (not gritty) when a piece is rubbed between finger and thumb.

Gardeners in Australia welcome every single drop of rain. I have heard stories of spontaneous street parties at the end of a drought. After it’s been raining for a while, though, some of us wish it would stop. Dense clay soils especially swell up and develop into a sticky slippery mess.

Clay lawns are prone to dollar spot or other fungal problems during wet periods. You can treat these with a good fungicide like Richgro Mancozeb (refer to label directions if applicable for your state). But very often the fungal infection is a symptom of poor drainage.


Here are a few things you can try if you are battling clay conditions:

  • Use a grass that is suitable for clay: buffalo has a robust root system that copes well with sticky clay
  • Keep the soil slightly moist year-round, if possible. Dried out rock-hard clay soils are difficult to revive.
  • If you are watering your lawn, water in the morning. Experiment with breaking up irrigation times. For example, if you are watering for 12 minutes, you could break it into 3 x 4 minutes, with 10 minutes between, to give the soil a better chance to absorb the precious water.
  • Aerate your lawn when it is actively growing, ideally in spring, ideally every year.
  • Apply Richgro Gypsum – also called clay breaker. It improves drainage and aeration of dense soils. The calcium content of gypsum also acts as a nutrient for the lawn. Apply at a rate of 1 kg per square metre, ideally straight after aeration. Very dense clay soils may need several application of gypsum per year.

It won’t happen overnight. But with a little patience you will reap the rewards of a clay soil: clay holds nutrients and water, and buffers dry spells much better than sands.



Happy gardening,



Richgro horticulturist