A soil is compacted if you can't push a pen into the dry soil. It happens from too much traffic on the lawn, standing water, and heavy clay soils lacking organic matter.
Compacted soil limits water infiltration, reduces availability of oxygen to roots, and physically restricts root growth. The best way to correct this situation is through regular aeration which can be accomplished through either a mechanical means or through a liquid application.
The aeration process is basically opening holes into the soil that allow oxygen and water to move through the soil. The aeration openings, or channels, provide a haven for root growth and biological activity. The accelerated root growth improves nutrient and water uptake. This in turn stimulates grass growth and results in a denser turf which helps to crowd out weeds.
The type of grass will determine whether to aerify in the fall or in the summer. Lawns composed of cool-season grasses such as Kentucky bluegrass and tall fescue are best aerified in the fall, when there is less heat stress and danger of invasion by weedy annuals. Allow at least four weeks of good growing weather to help the plants recover.
Warm-season grasses such as zoysiagrass, centipedegrass, carpetgrass, St. Augustinegrass and bermudagrass, on the other hand, are best aerified in late spring and summer, when they are actively growing.
With either type of grass, choose a day when temperatures are mild and soil is moderately moist, which makes the soil easier to penetrate. Avoid aerifying a wet soil, as it is messy and leads to further compaction of the soil as well. If the soil sticks to your shoes or if the core sample you take sticks to your probe, you should wait until it dries out some before starting the job.
Aerify is a liquid soil condition available from Back to Nature
Using a natural process, liquid aeration breaks up tightly bonded clay soil particles. In this process it relieves compaction, helps create humus, and brings about the aerated, living soil necessary for healthy plants.
One of the secrets to having lush lawns and fabulous gardens is having great soil. And that means porous, well-aerated soil where roots can grow deeply and where bio life can thrive.
Using a liquid soil conditioner you will experience the same benefits of mechanical aeration without the physical strain and messy plugs left on your lawn. Regular applications of liquid soil conditioners create “space” in the soil, allowing roots, water and oxygen to permeate.
Once you get oxygen into a clay soil, beneficial microbes will be able to survive. These microbes are needed to turn old roots and organic matter into all-important humus. If you have decent topsoil that has become compacted, a good liquid soil conditioner should penetrate to a depth of about 1' with your first application. Each succeeding application should give deeper penetration.
For poorer soils with high clay content, do not increase the amount of soil conditioner that you use. Instead do a follow up application 1 – 2 weeks after the initial application is watered in. Use every 3 months until the desired level of aeration is achieved. You should be able to easily insert a screwdriver into the soil, once the desired level of aeration is achieved. Once your soil has improved, 1 or 2 applications a year is sufficient.