To keep your lawn healthy and lush looking it needs to be fed with the nutrients that it requires in the right proportions. The lawn requires many essential elements to prosper and many of these are found naturally as trace elements in the soil, some are available from the atmosphere but some Nitrogen (N), Phosphorous (P) and Potassium (K) are not available in the ground in sufficient quantity. Most of the proprietary fertilisers available from garden centres, DIY outlets, supermarkets etc. contain these three elements in varying proportions and most will do the job effectively.
In general, when the lawn starts to grow in early spring this is a good time to put the first application of fertiliser on. After that you will have to make judgements as when the lawn needs more fertiliser and you will generally tell by the colour of grass and the general look of the lawn.
Fertiliser used on the lawn must be spread uniformly, to avoid disfiguring the grass. The fertiliser can be spread in several ways: by hand, by rotary spreader, or by drop spreader. Using your hand is probably appropriate for small areas where it is difficult to turn a spreader but probably the most accurate method is by the drop spreader which meters out a set quantity fertiliser per unit length. These drop spreaders are available for hire from most garden centres and plant hire companies and are those for normal sized gardens can be relatively inexpensive to buy. It is also a good idea to buy a fertiliser that is visible on the lawn so you know where you have fertilised and where you have not.
Keeping a lawn healthy minimises weeds infestation but inevitably weeds and moss will eventually find their way into the lawn. The easiest method to rid the lawn of weeds or weeds and moss is to use one of the many propriety weed and feed or weed, feed and mosskiller to rid the lawn of the problem.
It is essential that the manufacturers instruction are read before application of the product as often onorous conditions apply.
In trying to rid your lawn of weeds it may be necessary to make more than one application of the weed/mosskiller in a season and it is probable that it may need to be reapplied each year.