Lawns and Lawn Maintenance

Lawns

Lawns are often overlooked, but the correct growing conditions, a balanced environment and nutrients supplied by recycled organic matter are as important to an organic lawn as to the rest of the garden.
The ideal site for a lawn is one that is sunny, level and well drained. Improve the drainage of wet areas and choose suitable grass mixtures for partially shaded sites if necessary. However, do not even attempt to grow a lawn in deep shade, on a waterlogged soil or on steep banks. As an alternative in such situations, think about using ornamental mulches, ground cover plants or perhaps a planting of wild flowers.
If you are sowing a new lawn, choose a suitable grass mixture: a lawn used as a play area, for example, needs more of a hard-wearing mixture than a lawn which is primarily decorative. Whatever type of lawn you have, however, the following general principles apply to maintaining it.

pH

Check the pH regularly with a testing kit. On a soil that is too acid, grass debris will not decompose and a layer of dead material (known as the “thatch”) will build up on the surface. Nutrients are not recycled and moisture may not be able to penetrate. If necessary add ground limestone’to bring the pH above the level of 5.5.

Mowing

The key to a successful lawn is not to mow too closely or too often.
A minimum cutting height of approximately 3cm (1-1/4in) is adequate for most lawns. This will encourage a thick sward which is more resistant to wear and swamps weeds. Mow when necessary — frequently when the grass is growing quickly, but less often at other times. As a rough guide, mow the grass as soon as it is approximately 1.2cm (1/2in) taller than the cutting height. Do not allow the grass to get long and then cut it severely because this will weaken it.
Leave the mowings on the lawn whenever possible because if you always remove them you will be taking away fertility which has to be put back in some other way. However, it is not advisable to collect the mowings when the weather is cold and wet, otherwise they will sit in clumps on the surface and this starts killing the grass beneath the clumps. The mowings should also be removed if the grass has been left to grow too long before it is cut, or if weeds that you are trying to eliminate are in the process of seeding.
It does no harm to take away mowings every few cuts if you want to use them on the compost heap or in the garden.

Feeding

Make sure the lawn is well fed. For an initial treatment of a lawn in poor condition, a dressing of blood, fish and bone at approximately 70g/sq m (2oz/sq yd) applied in mid-spring is a good tonic. Otherwise, most of the nutrients a lawn required are supplied by returning the mowings.
An adequate supply of nitrogen is essential, and this is usually available if clover is present.
If clover does not occur naturally as a “weed” in your lawn, scatter seed into the grass in spring just after you have mown. Use wild white clover from a supplier of wildflower seeds or a dwarf pasture white cultivar from an agricultural seed merchant at a rate of 5g/sq m (1/5oz/sq yd).
The only additional nutrient that may then be required on some soils is phosphorus, which can be supplied to phosphorus-deficient lawns with a dressing of bonemeal at approximately 70g/sq m (2oz/sq yd) applied in spring. Never apply a fertilizer or other nitrogen-rich materials to the lawn during the autumn months.

Weeding

As long as the grass is growing strongly, most weeds will be kept under control. A few weeds are not only tolerable but desirable; remove problem weeds such as dandelions and plantain by hand.

General lawn maintenance

Little other maintenance is required on a healthy lawn because the earthworms will do most of the work for you. They draw almost all the debris down into the soil so thatch should not build up and therefore routine scarifying of the lawn to remove it should not be necessary. The earthworm burrows will also aerate the lawn, so no regular spiking needs to be done either. At the same time, the casts which the worms deposit on the surface act as a top-dressing into which new grass shoots can root. Spread the casts with a brush if necessary.
Encourage earthworms by making sure the pH level is over 5.5 because they dislike very acid soil conditions. Leaving some mowings on the lawn also helps by supplying the worms with a constant supply of succulent food and so increases their activity.
Renovating a neglected lawn If a thick layer of thatch has built up on a neglected lawn, this can be removed by vigorous raking or scarifying in autumn. Press the rake down on the surface of the lawn and pull it vigorously along to bring out as much dead material as possible. Once the pH has been corrected and the lawn is being regularly fed by returning the mowings, routine scarifying should not be necessary.
If small areas of a lawn have been particularly compacted through overuse, spike them with a garden fork. Drive the fork in vertically to a depth of about 10cm (4in), rock it gently back and forth and then remove it.
Top-dressing in autumn can even out bumps and hollows in a lawn. It can also improve the surface structure of a lawn on poor or heavy soils. Make up a mixture of approximately 4 parts loam, 2 parts sand and 1 part leafmould. You can modify the mixture to suit your soil by, for example, using more leafmould and less sand on a sandy sod. The loam should ideally come from a turf stack, but good garden soil and used potting compost are suitable alternatives. Spread the mixture over the surface with a shovel at a rate of about 1.6kg/sq m (31b/sq yd). Spread it as evenly as possible, using the back of a rake.
If bare patches appear after top dressing because large hollows have been filled in, sow these with grass seed before weeds establish themselves.  http://www.gardeninginfozone.com/lawns-and-lawn-maintenance