What Causes Moss to Grow in a Lawn?

Insufficient Sunlight

• Insufficient sunlight is one of the most common causes of moss growth on lawn. Lack of sun leads to poor turf grass growth and this encourages the growth of moss. Grass in shade is weak due to low light and elevated disease activity. Hence shady lawns have more moss related problems than the lawns grown in full sun.

Heavy and Wet Soil

• Heavy or compacted soil, as well as soil that is too wet, has low oxygen levels. Oxygen is vital to the growth of healthy lawn roots. Heavy soil, or that with a high clay or silt content, becomes waterlogged and allows moss to thrive. Similarly, soil that is poorly drained or excessively irrigated is an optimal environment for the germination and growth of moss.

Too Little Watering

• Oftentimes people hold back watering their lawns in the summer in anticipation of rain during fall. This lack of water is as likely to encourage growth of moss on a lawn as overwatering. When lawns are insufficiently irrigated in the summer, they thin out and brown and when it starts to rain in the fall, moss grows more aggressively in the weakened areas.

Improper Soil Depth

• The depth of the soil is an important consideration in order to maintain a healthy turf. Soil that is less than four to five inches deep is not considered deep enough to grow and sustain a vigorous turf. Hence in soil shallower than this, it is best to add a layer of topsoil before planting the lawn in order to grow healthy grass. The healthier the grass, the better equipped it will be to ward off unwanted predatory growth such as moss.