St Augustine is a Semi-Tropical Plant
St Augustine is a semi-tropical grass – it does not like cold weather. The escape mechanism to avoid death from the cold is to go dormant. When dormant, St Augustine leaves turn brown which makes the lawn look dead – it is not. Below the brown leaves are the stems, roots, and soil that are still full of life.
The brown leaves create an insulating blanket above the stems, roots, and soil protecting them from cold weather and more damage. Then as temperatures rise in the spring, the stems and roots will start producing new leaves. The older dormant brown leaves, fall off and are recycled (composted) into plant food. Soon the once brown lawn is now a lush green lawn again.
What To Do for a Dormant Lawn
Keep it tall. It may look lifeless, but just below the brown leaves are the stems, roots, and soil – all full of life. If you remove the brown leaves by scalping and bagging, the stems, roots, and soil will be exposed to the sun, dehydrate, and die. If you leave the brown leaves, they will protect the stems, roots, and soil, and your lawn will green up faster and become a lush green lawn again.
Keep it wet. Water is the fuel that sustains the life of the stems, roots, and soil. Water will promote microbial activity in the soil which will warm the soil. As the soil warms, it will reduce future cold-weather damage and encourage spring growth.
What Not To Do for a Dormant Lawn
Do not mow, rake, dethatch or aerate your lawn. If you must mow, mow at 4” or taller. Limit traffic from pets, kids, and equipment on a dormant lawn. Traffic will compact the brown leaves and reduce the insulating qualities for the dormant leaves and expose stems, roots, and soil.