ARTICLES

LAWN CARE

Mowing. Mowing is good for your lawn because it keeps the grass neat and promotes compact growth. The grass must be long enough to feed the roots but short enough to be manageable. For a general-purpose family lawn, this means cutting the grass so that it's about 2.5cm (1 in.) long. To achieve a "bowling-green" finish on a well-laid lawn of fine grasses, you will need to cut the grass back to 1.2cm (1/2 in.).

Begin mowing in March and finish in October. The more often you mow your lawn, the slower it grows; this is because every time the grass is cut, it receives a check in growth. Mowing little and often therefore, not only produces a better finish, but it is more efficient. Ideally, cut your lawn twice a week in summer and once a week in spring and autumn. To maintain an even sward, vary the direction of mowing from time to time. If you cut very infrequently, avoid cutting the lawn back too hard because this shocks the grasses and results in a loss of vigor, allowing weeds and moss to invade. Try to only mow the lawn when it is dry. During very dry periods, leave the grass cuttings on the surface, provided that the turf is free from weeds.

A lawn's ideal length will vary with the type of grass, but many turf grass species are healthiest when kept between 1 and 1 1/2 inches. You may have to readjust your mower - most are set too low. For a healthy lawn, mow frequently. Short clippings are tender and rot quickly. Set the mower blade high -- thicker lawns shade out weeds. Adjust the pH to 6.5 to 7.5, the range preferred by most grass species.

It is perfectly acceptable to leave the clippings on the lawn to feed the grass, provided you mow the grass regularly. Remove the longer, lush growth when you cut the grass for the first time each spring or after taking a holiday. Thereafter, provided the clippings are under 2cm (1/2 in.) long and they scatter evenly, they can be left. Any clippings removed from the lawn can be placed on a compost heap.

When mowing, the advice often offered is that you should remove lawn clippings or they'll make thatch. It is perfectly acceptable to leave the clippings on the lawn to feed the grass provided you mow the grass regularly because there will be only a relatively small amount of clippings and these will be short in length and therefore breakdown easily. According to research, thatch is often produced more by the misuse of strong fertilizers and pesticides than by clipping alone. Thatch is a layer of dried grass clippings that builds up on the soil surface. As long as this layer is less than 1/2 inch (2.7mm), it's harmless and in fact has some of the same benefits as mulch returning fertility to the lawn. A healthy soil biota can easily decompose the normal amount of clippings to keep the thatch layer from building up. But earthworms, which perform much of this task, are especially vulnerable to popular lawn chemicals.

However, all grass forms a layer of dead plant material, between the grass blades and the soil. When this has built up to a greater depth than the safe zone, raking the lawn or using a machine that slices through the thatch layer to break it up can reduce it. Sprinkling a thin layer of topsoil or compost over the lawn will also help.

Scarifying. Raking the lawn with a spring-tined rake helps prevents the build up of thatch. If it gets too thick, the thatch can smother the grass and reduce vigor. If the layer builds up over 2.5cm (1 in.), water can't soak through and the possibility of disease is increased. It is advisable not to rake heavily in spring as this can damage the grass. The grass doesn't also produce side shoots at this time of year and scarifying will open up the turf making it susceptible to weed invasion. You should start to scarify your lawn in late spring and early summer to remove patches of dead moss. Then in early autumn you can remove debris from the lawn and thatch that may have built up. If there is moss present, use a moss killer a week or two before scarifying.

Feeding. Most garden lawns need an annual application of nitrogen to maintain vigor and keep the grass looking healthy. The best time to apply a high-nitrogen lawn fertilizer is in spring when the grass is growing fast. You can also feed your lawn in autumn to help it build up a good root system and produce tough growth that can shrug-off diseases. Use a specialist autumn feed that has been formulated to promote the right growth.

Get your lawn in shape for summer by first aerating and then fertilizing it. Parts of the lawn that get heavy traffic, such as paths and play areas, will often become very compacted, impeding drainage. To help improve the drainage and avoid weed and moss problems, it's a good idea to aerate the lawn. The perfect time of year to do this is in September when the soil is moist. Aeration is the removal of small cores of soil from your lawn, which helps to break up compact dirt and packed mulch. Even more important, these holes allow vital air, water and fertilizer down to the root area. You can purchase a machine for this task or rent one from your machine dealer. Another excellent way of aerating your lawn is to push a garden fork into the ground to about 15cm (6 in.) deep and move it backwards and forwards to create air channels in the soil. Then push the fork in again about 10cm (4 in.) away and repeat the process until the whole area is done. One very simple way to aerate your lawn is by wearing a pair of shoes that have spikes on the soles. Pads containing spikes that simply fit under your shoes are available from garden centers, but if you have a pair of golfing shoes (with steel spikes), then these are ideal. Wear them when you spread the fertilizer. Once you've aerated the soil, it is a good time to apply a top dressing.

Most lawns need to be fertilized every year. They need more nitrogen, phosphorus and potassium than soils usually contain. These three elements are the primary ingredients found in most lawn fertilizers. It's important not to over-fertilize, however, you could do more harm to your lawn than good and it's best to use a slow-release fertilizer that feeds the lawn slowly. It's also important to check the soil's pH. Grass is best able to absorb nutrients in a slightly acidic soil, with a pH of 6.5 to 7.0. Acidic soil can be "sweetened" with lime; soil that's not acid enough can be made sourer by adding sulphur.

Top dressing is the application of a mixture of good quality soil, sand and humus to the surface of the turf. Top dressing is used to level out minor humps and hollows to produce a perfectly even lawn surface. The grass also grows denser as top dressing helps to promote the development of runners. It also improves the water-holding capacity of sandy soil and drainage is improved on heavy soils. Do not apply more than 12mm (1 in.) of top-dressing in any one area because you will smother the grass.

Nitrogen. Stimulates leaf growth and makes grass greener. Essential - this food is depleted quickly and needs applying every season. Important - do not apply in winter when active growth is not wanted.

Spring/summer lawn fertilizer. (1) Lawn sand (2) Sulphate of ammonia (3) Dried blood.

Phosphates. Helps to build up the root system. Essential - often needs applying every season. Vigorous root production is stimulated. Growth starts earlier in spring and side shooting is promoted in autumn.

Autumn lawn fertilizer. (1) Bone meal (2) Super-phosphates (3) Potash. Stimulates lush, healthy growth. Apply every season, but not essential. Evidence shows that this food toughens the grass making it less susceptible to drought, discoloration and disease.

Spring or autumn lawn fertilizer. Sulphate of Potash.

Watering. Watering properly will help your lawn grow deep roots that will make it stronger and less vulnerable to drought. It's best to water only when the lawn really needs it and then to water slowly and deeply. This trains the grass roots down. Frequent shallow watering trains the roots to stay near the surface, making the lawn less able to find moisture during dry periods. Courser, harder wearing lawns can survive lengthy periods without rainfall but, after time, will turn brown, greening up again as soon as the rains return. Always water in the evening to help reduce water loss through evaporation.