Algae on lawns

During wet weather a gelatinous slippery layer sometimes appears over the lawn surface. This is usually dark green or blackish in colour.

Causes
Algae on lawns is found where poor drainage causes a damp surface. Compacted soil, particularly around the drip line of trees or shrubs, is prone to algae. In very wet weather algae may appear on only slightly compacted lawns.

Control
Correcting the underlying conditions should clear up most of this problem. These conditions also favour moss growth. Treatment of moss will give incidental control of lawn algae.

If the lawn is waterlogged for much of the year, consider installing artificial drainage.

If the surface layer is poorly drained aerate to a depth of 7.5-15cm (3-6in) using a garden fork, every 10-15cm (4-6in).

Where the lawn is only compacted or waterlogged in patches, aerate in moist conditions every four to five weeks.

On heavy soils a hollow-tine aerator will give better results. After aerating top dress with sharp sand, working it into the holes to improve drainage.
< Back to Lawn & Grass Care Advice <<