A well fed, strongly growing lawn will pose minimal weed problems. Apply a balanced lawn fertiliser to support the main growth spurts in spring and again in autumn.
Nitrogen is what a lawn needs most for lush green growth, but a good lawn fertiliser contains the correct proportions of nitrogen and other essential nutrients. Phosphorus is essential for healthy root growth, the foundation of your lawn. Most lawn fertilisers also contain a little iron sulphate to reduce moss, and potassium for disease resistance.
For a new lawn, apply a lawn fertiliser to the area and rake it into the top 2cm of soil just prior to sowing. Make sure you choose a product suitable for new lawns and apply it at the recommended rate. Too much can burn the young grass. After the first three or four cuts, make another light application.
Odd weeds are easily banished using a daisy grubber (a simple, inexpensive hand tool, specially designed for the job), but when weeds have got out of hand, spraying is the easiest option. A selective lawn weed spray will take care of the broadleaf weeds without killing the grass.
Repairing and patching small areas of lawn can be achieved simply by ‘over-seeding’ in spring or autumn. Before sowing prepare the ground so that the seed can make good contact with the soil. Mow the lawn short and then remove debris and weeds. Use a hard steel rake to remove thatch and create shallow grooves in the soil. For extra assurance, sprinkle over some weed-free topsoil or lawn mix, then scatter the seed, and water gently with a sprinkler or watering can. Water to keep the seed bed moist and feed as you would a new lawn.
A freshly mown lawn gives any garden an instant facelift. It is also an important form of pruning; it stimulates branching from the base of each little grass plant, ensuring a close knit, weed-free lawn. Set your mower height to suit the growth rate and your grass type. Fine grasses generally withstand closer mowing than coarse grasses. Mower blades should be no lower than 2cm above ground level, higher in summer and winter when growth is slow.
Refrain from mowing when the ground is wet as this can turn the soil as compact as concrete, more likely to end up as puddles than healthy green lawn.
Any lawn in constant use will eventually suffer from compaction. Once the roots are starved of air no amount of feeding and watering will revive it. If your lawn has become compacted, it can be improved with ‘spiking’: While the ground is damp (but not sodden wet) use a garden fork to make holes 10cm deep at 15cm intervals. Ease the fork back and forth slightly before removing it. Brush sandy soil into the holes and further improve the aeration. For large areas consider hiring a mechanical corer.
Another way to let more air into your lawn is to get rid of the old roots and stems that have built up at the base of the grass. Thatch can be beneficial up to a point, acting as a natural mulch. But when it builds up to over 1.5cm thick it becomes a barrier to water and nutrients and a disease risk in warmer weather. Excess thatch can be removed by close mowing followed by vigorous raking. Finish with thorough watering and feeding.
If your lawn is poorly drained no amount of thatching and spiking will help. On sections where the water lies close to the surface in winter it’s best to install some kind of drainage before sowing a new lawn. Professional advice is often called for, and worth the investment. Alternatively, consider an expanse of decking or a bog garden.
Established lawns need regular moisture in order to stay green. For dry climates with summer water restrictions, there are drought tolerant lawn varieties.
For a newly sown lawn, watering is essential to keep the soil constantly damp, but take care not to over water as this can lead to damping off disease. Water daily in the absence of rain or up to several times a day in hot or windy conditions.