SEPTEMBER is a good time to work on the lawn, starting with repairs and finishing with the autumn routine of scarifying, spiking and top dressing. However, because this can be a backbreaking job on large areas it is a good idea to concentrate on the parts showing signs of wear or poor drainage rather than tackling the whole lawn.

Broken edges can be made neat by cutting a square of turf behind the damage, prising it free, moving it forward and trimming off the broken part. Loosen the soil in the gap left behind, fill with more earth so it is level with the rest of the lawn and sow with grass seed.

Bumps show up as bare or poorly-covered areas that get shorn to soil level each time the lawn is mowed. If the turf is still reasonably good cut around the bump and then make one cut across the area. Loosen and peel back each of the two sections then remove as much soil as is needed to make it level. Tread down the remaining soil then replace the turf and firm it down, filling any cracks with sifted soil. Use the same method for hollows but fill with soil instead.

Apart from being caused by bumps, bare patches can also be the result of excessive wear, weed removal and deep shade under a tree. The area can be repaired but will probably return if the initial cause isn't attended to.

Shade under a tree is difficult to solve without the drastic step of cutting it back or completely removing, but it is worth reseeding the area with a grass variety that will tolerate those conditions.

If the lawn is used a lot by children in summer, it is a good idea to use autumn and winter for getting it strong and healthy for the following year. Re-seed the worn areas with a tough grass suitable for constant use and during the growing season set the mower higher than usual to give a longer cut.

After the lawn is mended, it can be scarified to remove debris and thatch, which is a layer of material that builds up on the surface of the soil.

A thin layer of thatch is good for the lawn because it reduces water loss and makes it feel springy. However, if it gets too thick it impedes drainage, thus causing water logging and, because of this, increasing the likelihood of disease. Scarifying is usually done with a spring tine rake drawn through the lawn with hard downward pressure as it is brought towards the user. Avoid areas that have been recently seeded or turfed.

Aerating follows scarifying and is used to get water and air beneath the surface of the lawn.

Use a garden fork and push it vertically about 10cm/4inches into the lawn gently rocking it back and forth before removing it.

Repeat every 15cm/6inches over the area but remember that it is not necessary to do the whole lawn, just treat areas that are compacted. These will show up as having some of the following symptoms; water logging after rain, rapid browning in dry weather, trailing moss, bare patches from constant use and poor grass growth.

Top dressing is used to fill in small hollows and build up the soil layer in which the lawn is growing. It is a mix of peat or peat substitute, sand and good garden soil in different ratios according to the type of soil it is being applied to.

More sand, for example, would be used on a heavy soil, while more loam would be added to the mixture used to dress lawns on a sandy soil.

Put small heaps of the top dressing mixture over the lawn then use the flat back of a garden rake to spread it evenly over the lawn and down to soil level making sure the grass is left clear when finished.

Updated: 08:41 Saturday, September 21, 2002