Quit worrying about taking care of the turf grass! Take care of the soil first and it will give the turf grass what it needs to take care of itself. This does not mean that you should not use fertilizer or other programs – it does mean you need to keep the soil and its nutrients in mind when you are looking at a lawn site.
Good soil has more than dirt in it. It has plants, bacteria, moisture, oxygen, nutrients – and yes – sometimes even insects and worms. The bacterium feed on biomass (organic matter.) The biomass helps bind the dirt while spreading the dirt particles and helping the soil to breathe. The bacteria also help make nutrients available to the plants. As the plant goes through its life cycle, it provides biomass back to the soil. This is a loop that can build or destroy itself and is necessary to good soil. To the author, the level of activity in this loop is the best determinant of how healthy the soil is. The higher the level of activity, the healthier the soil.
Most of the soils are some type of alluvial clay. There are many things that can be done to improve this clay. Adding gypsum is one way of loosening the soil. In extreme situations (or when putting in a new lawn) tilling in biomass, nutrients and sometimes a surfactant can help. This provides the ingredients for a healthy soil. Another thing that can be helpful is to stimulate the soil by inoculating it with bacteria. This is similar to giving a cow with “scours” a bacterial pill which puts the bacteria back in her stomach so she can digest her food. One simple way to do this is by topping the lawn with compost or composted manure. Either should help distribute bacteria useful to the soil.
The final thing that is absolutely necessary is moisture. No matter how what you do for the soil, if there is no moisture all you have is a bunch of “stuff” and no plant can live in it. Applying moisture can also help stimulate the soil, and push the turf to protect itself. The general rule is to water “deeper” but less often, and not to water “shallower” and more often. In addition to minimizing the disease problems, this drives the roots down into the soil. The deeper roots help build a deeper soil. When the roots are deep it increases their ability to get nutrients and water. It also helps protect them from extremes of heat and cold. Let the soil get fairly low on moisture occassionally as soil and turf grass normally are comfortable with swings in the moisture level. That is the way nature does it in this country. One way to check the moisture level by sticking a knife in the soil and checking the moisture level with your finger.
In summary, look below your turf, at the soil. Caring for the turf best done by building the soil at the same time.