The garden in September
After the summer heat numerous lawns look pretty unattractive. Surfaces with spots of dry grass must be reseeded.
Best is to scarify (verticut), seed and top with sand or GramiTop the whole lawn. With a boost fertilizer and generous watering your lawn will soon look deep green and healthy again.
If time is an issue, then a new lawn with turf rolls will take only a few days work.
It is possible to fight weeds and moss until the end of September, should you wish so.
Conifers and evergreens such as rhododendrons root and grow better if planted in September/October rather than in late fall. The roots develop much stronger in the warm soil then shortly before winter.
Also a good time to trim your hedge. Especially more delicate species such as boxwood or cherry laurel will get fewer brown spots than during the summer heat.
Mow your lawn frequently, but not to short (ideally cut 1/3 of the blade)