Curing Clay

Clay is a common problem in many areas causing water logging in the wetter months, and excessive dryness in Summer.

How do I know if I have a clay problem?

Pottery wheel   Boots covered in clay
Do you have so much clay in your soil that
you can do this?
  Do you get taller when you walk over your soil
when it is wet?

If so... you have got problems!

What can I do about it?

Curing clay can be time consuming and require a lot of dedication, but you will be rewarded with a garden that will be a more versatile place for a wider variety of healthy plants.

A great way to combat clay is to raise your garden beds by working through some good-composted soil and the liberal use of mulch. This will improve drainage straight away. In the long term the soil beneath the raised beds will improve because it is being enriched by the compost you have added above.

Some plant varieties such as fruit trees, should be not be planted into heavy clay soils at all. Plant them using the methods described in the Bareroot guide and Potted Plant guide.

If I do nothing?

Not only will your plants be stunted, the soil in your garden will be more difficult to work with. The soil will be too dry in Summer and too wet in Winter.

Technical Bit

Clay is made up of microscopic particles that form together and act like a sponge, attracting and holding water, which results in poor drainage. You need to break this bond by adding gypsum and / or compost which will improve the drainage.


Apply 1 - 2 kg (2.2 - 4.4 lb) of Gypsum per square metre. You may need to reapply depending upon the severity of the problem. It can take a while. You can also use liquid clay breaker which will penetrate the soil quicker than gypsum, but you still need to be patient while it takes effect.