There are four seasons of the year and ironically there are four different seasons of lawn care as well. In spring, lawn care companies do most of the work in lawn care. The first, and most common, is lawn aeration. The lawn care company will come with a large machine that removes cylinders of dirt from your lawn. This loosens up the soil so that nutrients and water can get to the soil better and the cylinders of soil that are deposited on the top of the grass gives the top layer some nutrients as well. Another thing that can be done is the spring is re-seeding. Many times people's lawns develop patch grass in certain areas. By simply laying seed again there is a good chance that the grass will start growing by the time summer comes around. During the summer - there is not much that can be done except continually water your lawn.
During the fall months there can be much done to your lawn. Once again the lawn can be aerated, if it was not done in the spring and re-seeded. There also can be a fertilizer laid on your lawn that is slow release. This will provide nutrients in your lawn all winter and will allow your lawn to come into spring healthier. In the winter, the only thing that can be done is to lay spider mite treatment. Many times these mites will damage your lawn so much in the winter that it looks like your lawn just died after the winter.