Gardening expert Monty Don has shared three important lawn jobs to complete in September, which can help ensure lawns are thick and green next spring. September is one of the most important months in a gardener’s calendar, preparing the garden for autumn and the following spring.
According to Monty Don, September is an ideal time for these tasks because the weather has cooled down and lawns should have recovered from the heatwave. In a 2024 blog post, he recommended sowing grass seed, repairing lawns, and aerating lawns.
Sow grass seed and repair lawns
Monty Don wrote: “This is an ideal time of year to either sow or turf new grass or to repair patches and worn areas on your lawn.”
He advised: “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.”
Monty Don advised gardeners not to mow the lawn for at least a month, and if it looks “unsightly” going into winter, clip the new growth with shears. For a larger area, he suggested cleaning the edges with a sharp shade, forking it over to remove compaction, and either scattering with seed or cutting a piece of turf to fit, ensuring the edges butted tightly against the existing grass.
He added: “Like grass seed, it is important that turf should not be walked on or mown until growing vigorously, which will indicate that the roots have become established and are growing strongly. Depending on the weather, this may mean leaving it uncut until next spring.”
Aerate lawns
Another popular September job is aerating the lawn, which improves airflow, water absorption, and nutrient access for grass. Monty Don said: “Even if your lawn has come through the summer unscathed, it is always a good idea to aerate it at this time of year.”
He explained: “You can use a fork by working the tines into the ground at 12-inch intervals or, for a larger lawn, hire a rolling hollow-tine or slitter. Ideally, this is followed by working sand into the holes they create with a stiff brush.”
Finally, give the lawn a thorough scratch with a wire rake to remove all thatch and moss. While it will look a little threadbare, the lawn will be completely “rejuvenated” next spring.
