Gardening expert Monty Don has shared a simple rule for repairing lawns in September, helping grass look thicker and greener by autumn. With many lawns struggling after record summer temperatures, the cooler weather now offers the ideal window for recovery.
Why September is the best time for lawn repair
September is the ideal month to repair a lawn because the cooler weather reduces heat stress on the grass while the soil remains warm enough for seeds to germinate quickly. However, simply scattering seeds without preparation is ineffective, as an unhealthy lawn often contains dead foliage that can choke new growth.
Monty Don, one of the UK's best-known gardening experts, advises raking over thin patches to improve the chances of recovery. On his website, he said: “If it is just a worn area of thin grass, rake away all thatch and moss and remove all weeds and thinly scatter grass seed, watering well and keeping it damp. The seed should germinate and grow in days.”
Scarifying to restore stressed lawns
Raking over a stressed lawn is a technique known as scarifying, which creates space for new grass to grow. Most lawns in the UK may have stopped growing entirely due to the extreme heat, leaving gaps that allow moss to take over. Moss competes with struggling grass for resources, making recovery harder, especially during rainy autumn weather.
Dead grass also accumulates beneath the surface, forming a thick layer called thatch that prevents new seeds from reaching the soil. Scarifying removes this buildup, encouraging water to reach the soil and helping grass roots grow strong.
How to scarify a lawn
It is best to scarify the day after rain, when the soil is slightly moist and softer to rake but not overly wet. Mow the lawn first to reach the thatch, but avoid cutting the grass too short to prevent additional strain. Then, pull a rake firmly towards you, applying pressure to reach the base of the grass.
Rake in different directions each pass to loosen any missed material. Dispose of moss and thatch in the bin, as leaving it in the garden can attract pests. Water the lawn thoroughly and avoid mowing for at least a month after seeding. The grass should look thicker and greener by the time autumn arrives.
