Symptoms of Compaction

If you have neglected your lawn aeration then it is likely that it will become compacted, and you’re going to see the effects of a poorly aerated lawn as follows:

Thatch Layer

Thatch is one of the main symptoms of poor air infiltration and compaction in a lawn. A compacted soil holds little air or water and cannot sustain a normal and healthy population of microbes and beneficial fungi. It is these guys that keep the natural balance of life, death and decay going in your lawn. Without microbes, the decay will almost come to a stop. This means that as new grass plants develop and grow the older ones die and just build up in a layer underneath causing a spongy ‘thatch layer’.

Once developed beyond a reasonable thickness (1/2”), this thatch layer acts as a barrier to water, air and nutrient penetration, further exacerbating the lawn's problems. Thatch layers can also occur in patches around the lawn, normally in conjunction with localised compaction and or dry patch.

See the Scarifying & Raking Category for more detail on dealing with thatch.

Other Symptoms

There are other symptoms that a poorly aerated or compacted lawn may exhibit. The problem is that these may have other causes than just lack of air. The fact is a compacted lawn is an unhealthy lawn, so an unhealthy lawn, whatever the cause, may have similar symptoms.

Lawn Disease

Resistance to disease will decline, and susceptibility will increase. Perhaps the most typical disease will be fusarium in autumn and winter, but also red thread in the summer and rust in autumn.

Worms in the Lawn

More than likely there won’t be any! Worms do some natural lawn aeration so the chances are they gave your lawn up as a bad job a long time a go!

Grass Colour

Generally compacted areas have a distressed, dry ‘old’ look to them. Quite often when you add fertiliser they take on a ‘bluey’ tinge due to lack of moisture to assimilate the fertiliser properly.

Rain Run-off

Though clay soils once dry take a bit of wetting, you will find compacted soils cause run-off quite easily.

Rapid Drying

Because of the poor moisture holding capacity of your lawn, it will dry more rapidly than other lawns or perhaps neighbouring lawns that are well tended. This may or may not be localised in your lawn in patches, often caused by excessive use, dry patch or tree roots.