It's not as complicated as you think....
The basic principle of lawn care is to carry out several straight forward routine tasks which are designed to keep the grass vigorous as well as attractive, which means that troubles are kept at bay. Thus, a proper maintenance programme is a series of trouble preventing measures and not a series of emergency treatments. Set out below is a list of essential tasks.
This is the most important task and must be done at the right time and with the blades at the correct height according to weather conditions and time of year. The blades must be sharp and properly set. Start the season on a high setting and gradually lower it. For the average utility lawn, the cut should be between 13mm and 40mm. Mowing too closely commonly results in poor quality lawns.
Lawns can die back in dry weather, resulting in brown patches. The grass will grow again when the rain starts, but it can be slow, allowing drought-resistant weeds such as yarrow and hawk bit to establish. Water the lawn thoroughly during dry or drought periods to saturate the top 10 - 15cm of soil. A useful way to find out if sufficient water is being applied is to make a small test hole in a border at the side of the lawn, to see how deep the water has penetrated. By noting the duration of watering needed future watering can be applied more accurately.
Constant mowing creates a serious drain on the nutrient reserves in the soil. Feed lawns annually in spring with a high nitrogen rich fertiliser. From late spring to late summer apply a proprietary spring/summer fertiliser if there is a decline in vigour loss of colour. Apply fertiliser when the soil is moist, during showery weather, or water in after application. In early autumn, after raking and aerating and before top dressing, apply fertiliser. Use a proprietary autumn lawn fertiliser with high potash and low nitrogen content. For even coverage use a spreader.
Don’t wait until the problem gets out of hand. Occasional weeds can be pulled and patches of moss indicate that the growing conditions must be improved. Apply a weed killer or moss killer promptly as soon as there is an obvious invasion. Lawn weed killers spread through the plant. Typical effects are twisting and contortion of weed stems and foliage, occurring within a few days of application. They do not harm grasses at normal dilution rates but should not be used on seedling grasses. There is a wide range of proprietary weed killers in various forms. The most popular method is to weed and feed at the same time. This is because selective weed killers work better when a nitrogen-rich fertiliser is used with it. Applying a fertiliser 1-2 weeks before weed killer treatment can be even more effective in controlling weeds.
The lawn is aerated by driving in a fork or other spiked instrument at intervals to relieve compaction, when doing this drainage is improved and new growth is stimulated. Aerate at least once a year if the ground is badly compacted and moss is present. It should be sufficient to aerate once every 3 years if a hollow-tine fork is used.
Raking the lawn with a spring-tine rake has several benefits. The build-up of thatch is prevented and the surface debris is removed. The removal of autumn leaves is essential never leave them on the surface over winter. Raking up creeping stems of weeds before mowing helps with their control.
Top dressing is the application of a mixture of loam, sand and organic matter to a lawn to correct surface irregularities and encourage thickening of the turf. A simple formula is 3 parts sandy loam, 6 parts sharp sand and 1 part peat substitute. Apply at 2kg per m². Work the dressing in with the back of a rake. Mid-September is the best time and spiking a day or two before top dressing will greatly increase the benefits, particularly in heavy soil.