How do I improve the clay soil in my lawn without digging up the lawn and replacing the soil? My lawn gets waterlogged and soggy in winter.

• Apply gypsum at a rate of 2-3 handfuls per square metre in spring and again in autumn. Gypsum works by breaking down the organic matter in clay soil.  
• It is a slow process that takes months, even years, it won’t happen overnight.
• Alternatively, there are spikes you can purchase from hardware stores and garden centres to strap on to your shoes that you can walk over your lawn to aerate it and help improve drainage.
• Once you have aerated your lawn apply a light layer of Tui Lawn Preparation mix to the area to fill in the holes, this adds organic matter to the lawn and helps improve the soil structure. 
• This can be repeated each year in late winter/early spring when the soil still has moisture in it and the spikes can penetrate the clay soil easier.