The start of September marks the beginning of meteorological autumn, when temperatures cool, days shorten, and leaves begin to fall. Despite summer drawing to a close, the weather often remains warm and sunny enough to enjoy outdoor spaces, and with rain gradually returning, garden lawns are beginning to recover after an exceptionally hot and dry few months.
The summer's heatwaves left many lawns looking patchy and brown, as hot weather can stress grass and halt its growth. However, it is possible to revive parched grass with a simple September rule: regular mowing.
How often to mow in September
According to gardening experts, grass should be cut every one to two weeks during September. This practice encourages grass to grow back greener and thicker, while also helping to prevent weeds from developing and stealing nutrients.
In its online advice, The Turf Doctor explained: “Regularly mowing your lawn helps make the grass greener and thicker. You might have heard that getting your hair trimmed regularly helps it to grow faster, and the same goes for the grass on your lawn!”
Regular mowing stimulates grass to grow thicker and greener through what is known as the “stimulation effect.” When mowed consistently at a decent height, the top portion of the grass blades is removed, prompting the grass to produce new shoots and leaves. This stimulates lateral growth, promoting a denser turf as the plant compensates for the loss of leaf on top.
Avoid cutting too short
The Turf Doctor added: “Plus, regular mowing has the additional benefit of preventing weeds from developing, so your grass gets a greater share of all the good stuff: available sunlight, nutrients, and water. It can allocate more resources to growth, leading to a thicker and healthier lawn with a lush green appearance.”
While regular mowing is encouraged, cutting grass too short can weaken the leaves, making it thinner and less able to compete with weeds. To avoid this, gardeners should raise the mower blade to around two to three inches off the ground. This adjustment reduces stress on the lawn and helps the blades retain more moisture, keeping it green and healthy.
RHS advice for September mowing
The Royal Horticultural Society recommends mowing lawns when conditions are dry in September, while keeping the cutting height high. The RHS said: “Mow in dry weather as and when needed, keeping the cutting height high. This will help the grass withstand the last of the warm, dry weather, and also make it more resilient to being walked on when wet weather arrives.”
