Algae are the most primordial green plants and can be an issue in the grass when the surface is very damp. They are more common in low, shady, or compacted regions. On the soil or on thin turf, algae create a greenish to black slime. As this blackish muck dries, it forms a crust that eventually fractures. Turfgrass plants can become chlorotic, feeble, and die.
Algae may form when the grass canopy is thinned enough to allow enough air, light, and water to reach the thatch surface. Algal development is most vigorous in late spring, summer, and early fall when warm, humid conditions favor algae growth and grass thinning. Mowing heights that are too low, shady situations, poor soil drainage, and frequent watering all stimulate algal development in the grass canopy.
Algae have traditionally been thought of as secondary colonizers, filling up places where grass density has been reduced due to some other cause. However, accumulating data suggests that excessive levels of algal activity can cause putting green grass weakening, presumably through the creation of toxins or competition for air, water, and nutrients. During seasons of warm and humid weather, an active algae control program may significantly boost the density and general quality of putting greens.
Signs and Symptoms
Blue-green algae are a serious pest concern in the turfgrass business, despite the fact that they do not infect grasses. These creatures, like plants, have chlorophyll, yet they develop by creating chains of thread-like cells, similar to a fungus. Algae symptoms emerge where the grass canopy has been decreased due to poor growing conditions or other pest activities. A green or black mat of fuzzy growth can be seen in the grass canopy or on the surface of the thatch in certain regions. During dry seasons, this algal development generates a dry, cracking crust on the thatch surface, repelling water and impeding grass regeneration.
How to Prevent Lawn Algae
Change the growing circumstances to make it less conducive to the growth of algae.
Core aerate and prune low-growing or thick foliage.
Improve a lawn’s drainage patterns. This can be challenging, but if algae is a persistent issue, it may be the only option.
Reduce the quantity of water that falls in the region.
Mow higher to allow grass growing in a shaded area to get more sunshine.
Once the algae have dried, it may be scraped out, but care must be given not to harm the surrounding grass. After the algae have been removed, the area may be core aerated and over-seeded to increase turf density.
Cultural Control
Test the soil to determine the amount of lime and fertilizer required. The pH of most turfgrasses should be 6.0 to 6.5. Soils that remain moist due to inadequate drainage should be shaped so that water drains away from the region. In rare circumstances, moist conditions may necessitate the construction of tile drainage. Avoid using light, frequent watering. Before irrigating, wait for indicators of moisture stress, such as the formation of a bluish-gray, dull tint. Irrigate the soil to at least 6 inches depth. The majority of healthy turfgrasses require roughly 1 inch of water each week. If there is puddling, cease irrigating and allow two to three hours for the water to seep into the soil before re-irrigating.
