Maintaining a nice lawn with a clay soil supporting it can often be very difficult, with the greatest problems arising from the lack of drainage. This is a problem for lawns when water will not flow away from the root zone quickly enough, and as a result - lawns and their roots can often become water logged and die. The second great problem comes with the lack of oxygen in the soil. Oxygen is vital to the roots of lawns and all other plants, and with clay soils this oxygen is often removed.
With these factors in mind, our repair or alteration of clay soils will be to give the soil greater free flow of both water and oxygen. There are several ways to achieve these aims, and the right way for you may depend on individual soil factors, the cost of repair, or the current quality of the turf in the affected area.
The Lawn Coring method is best suited to established lawns in good health, or where cost is a significant factor.
A lawn coring machine is used to go over the entire lawn surface, the machine will removes hundreds or even thousands of plugs of soil, thatch and turf, leaving the lawn littered with holes.
Gypsum and Wetting Agents should then be applied and watered into the lawn, gypsum is an excellent clay breaker, while Wetting Agents aid in water penetration throughout the soil profile.
Lawn Fertilising is always done at the same time as lawn coring, while it won't necessarily aid in drainage, it will benefit the lawns health greatly.
The holes left over from lawn coring can then be either left open to be refilled with new lawn roots and self levelling of the soil. Alternatively, the lawn can be top dressed with sand or a sandy loam which will fill the holes and help aid in drainage for several years to come.
Gypsum is sold in small bags at garden shops, is relatively inexpensive, and is applied in small quantities.
This method is best used when there is very little or no lawn.
The existing clay based soil is generously topped with a mixture of sandy loam and clay breaking Gypsum. The soil is then Rotary-Hoed to mix the entire top soil ingredients together. This breaks up the existing compacted clay soil, and mixes in some good draining soil and clay breaking Gypsum to significantly increase the top soil drainage of the lawn for many years to come.
This is a far more aggressive method and is best suited to sparse, new or non existent lawns.
The entire top few inches of soil will be removed from the lawn area and then removed from the property. The sunken area is then filled with a high quality top soil purchased from a soil supply outlet. Most soil suppliers will sell specific mixtures which are best suited for the local environments, so a quality soil supplier can best recommend the new top soil most suitable for your lawn. These will usually have a component of percentage of sand, of high level of sandy loam to counteract the effects of the clay soil.
A depth and replacement of 6-12 inches of soil can benefit the lawn for almost it's entire life.
Maintenance of clay based soils my need to continue on a regular basis over the life of the lawns when drainage problems re-arise.
This is most easily achieved with applications of Gypsum and Wetting Agents, and lawn coring once every few years or when required.