Understand what your lawn is telling you

Shade, persistent moisture, compaction, weak growth or mowing too closely can all favour moss.

Start by improving the underlying conditions. Where appropriate, treat the moss first, then use heavy scarification to remove the dead material. Hollow-tine aeration can relieve compaction where necessary, while maintaining a sensible mowing height and improving light or drainage where possible helps the grass compete.

Possible causes include drought, low nutrition, waterlogging, scalping, dog urine, disease or root-feeding pests.

Start by checking the soil moisture, timing and pattern rather than reaching for a feed or spray. It may simply be a lack of water during dry weather or drought; other cases may need a mowing adjustment, improved drainage, suitable nutrition, or targeted pest and disease action after a proper diagnosis.

Prolonged dry weather, compaction and low organic content can exaggerate shrinkage and cracking.

First assess moisture, soil type and compaction. Deep, sensible watering may help during dry periods, while hollow-tine aeration and suitable organic dressing can improve structure over time. Levelling requires soil or a soil-and-sand mix and is best completed before seeding.

Weed seeds are always arriving, but they are much more likely to establish where thin grass and bare patches give them contact with the soil. Compaction, close mowing, wear and seasonal stress can all create those openings.

The first aim is to correct why the turf is thin and improve grass density so there is less open soil for weeds to colonise. Existing weeds can be removed manually; a selective lawn weedkiller may also be appropriate in some lawns, but weed removal alone will not stop the problem returning while gaps remain.

Wear, shade, drought, compaction, thatch, poor mowing, pets and failed establishment are common causes.

Correct the cause first. Where overseeding is appropriate, selected seed is lightly covered with about 3 mm of organic dressing, followed by pre-seed fertiliser and consistent establishment moisture.

Compaction, heavy soil, excessive thatch, poor levels or an underlying drainage problem may be involved.

First identify whether compaction, the lawn levels or a deeper drainage problem is preventing water movement. Hollow-tine aeration can improve surface compaction, while repeated pooling may need level correction or drainage work rather than another feed or spray.

Dense shade, tree-root competition, dry soil and heavy leaf fall can prevent even good seed from establishing.

First decide whether the area receives enough light and moisture to support grass. A higher cut, shade-tolerant seed, careful watering and prompt leaf removal may help. In very difficult positions, shade-tolerant planting can be more successful than repeatedly reseeding.

Poor preparation, natural settlement, worm casts and mole activity can all play a part. Heavy rain and repeated wetting may contribute to settlement; foot traffic and other pressure, especially on wet soil, reduce pore space. Where this happens unevenly, dips and raised areas develop.

First establish whether the main cause is compaction, settlement or poor preparation. Levels are best corrected before seeding. Existing lawns can still be improved more gradually: minor defects may respond to a suitable sandy lawn top-dressing worked through the grass. Deeper hollows may require lifting the turf, filling and firming with suitable soil, then replacing the turf or reseeding. Hollow-tine aeration can relieve compaction, but will not level a larger dip by itself.