The lawn is made up of millions of individual plants, and as with other parts of the garden, a healthy and fertile soil with a good soil structure is essential to obtaining good results. Feeding the lawn should not be necessary unless growth is poor, in which case an organic fertilizer such as seaweed meal can be raked in as a top dressing, or else garden compost can be thinly spread over the lawn surface. An annual top dressing consisting of a mix of 3 parts sharp sand, 1 part loam and 1 part bulky organic material on heavy soils where moss is a problem can be beneficial, as can 2 parts loam to 3 parts bulky organic material on lighter, free-draining sandy lawns. Over-fertilizing a lawn, however, can actually reduce biodiversity. Many plants, in particular legumes such as Clover, thrive in nitrogen-poor lawns, and adding nitrogen can eliminate these plants.

Acid soil conditions can cause a build up of fibrous organic matter and debris called thatch, and can also encourage weeds such as sheep’s sorrel. If the pH is below 5.5-6, lime the area to raise it to around 7. Ground limestone ordolomiticc lime evenly sprinkled over the lawn and gently raked in is the appropriate organic treatment. Repeat annually if required until the desired pH is reached. Vigorously raking the lawn in autumn with a lawn rake to remove debris and leaves is known as scarifying. In addition to preventing diseases and removing obstructions to the growing grass, this process will help the lawn to thicken up by encouraging side shoot production.

Aerating the lawn is the process of creating holes in the soil in order to improve drainage and increase air circulation, and can be particularly beneficial on compacted areas. This is best carried out in early autumn when the soil is moist. A special hollow tined aerator can be used, which takes out a core of soil about 10 cm (4”) deep, or else the soil can simply be spiked with a fork on small areas. Most lawns should not need to be aerated more than once every three years or so.