Autumn ideal to get that lush lawn

TIME TO SOW: Lawn grasses establish best in autumn.

Autumn is the best time of year to be sowing a new lawn or patching up the existing one.
Nothing complements a house and garden more than a healthy, lush looking lawn. A quality lawn can enhance your property and is an inexpensive way to improve the look of your home. There are tried and true methods to having a healthy lush lawn for yourself, that are not hard but involve seasonal, timely work.
Lawn grasses establish best in autumn, from March to the end of May, or in spring from September to November. The soil is still warm and autumn rains will soon moisten it completely. In areas where early severe frost can occur seed should be sown in spring from September to November. As long as preparation is thorough and water is applied, as necessary, a very good lawn can be established now.
A really good lawn can be obtained only by intensive soil preparation BEFORE sowing; once the lawn is established it is difficult to level off an uneven surface or eradicate undesirable grass and weed species.
Initial Preparation
The first step is to remove all existing pasture type growth. Most grasses and perennial weeds are effectively controlled with glyphosate based sprays such as Grosafe Glyphosate, Yates Zero or Roundup. Harder to kill species such as blackberry, onion weed and english ivy can be removed with the use of Roundup Tough. The spray is taken in through the foliage, then translocated to all parts of the plant including the roots and rhizomes. Visible effects are a gradual wilting and yellowing of foliage, and brown-off may take 7-14 days or longer depending upon growing conditions.
If top soil has been brought on to the site it is best not to sow immediately but to leave bare for about 2-3 weeks, allowing any weed seed present to germinate which can then be sprayed with an appropriate weedkiller depending on the weed type.
It is important at this stage to consider drainage. Most grasses prefer a well drained loam or sandy loam soil rather than heavier wetter soils. Good drainage means better penetration of water and air to the grass roots. It also means moss and hydrocotyle weed, which can thrive in moist lawn areas, are less likely to invade the lawn. On some very heavy soils it is wise to import some sandy loam soil, spreading it over the area 8-10cm deep and incorporate it into the topsoil. In extremely wet situations permanent drainage may need to be installed. If soil is added, you may need to destroy any secondary emerging weed seedlings. It is worth putting time into preparing the soil to the correct levels and contours. For small areas a rake, fork and spade will suffice but for larger areas a rotary hoe will save time. The soil should be worked up to a depth of about 8cm using a rotary hoe or garden fork until the soil is a fine tilth. Any lumps or clods should be removed or broken down. Level and compact lightly, making the surface as even as you can to avoid humps and hollows. The area should be left to consolidate for a week, walking over the area for grading, raking and destroying weeds plus watering or rainfall will help with this process. If the soil is still soft and spongy all over rolling may be necessary. To avoid too much compaction only roll or tread the soil when it is damp, not wet. Rake the area again after rolling or treading.
Pre-application Fertiliser
When your new lawn has a 5-10mm layer of loose soil it is time to apply a pre-seeding dressing of fertiliser. Scotts Lawn Builder 'Seed and Turf' starter fertiliser or Tui Lawn Fertiliser at the rate for sowing new lawns (prescribed on the bag) can be used.
Fertiliser must be spread evenly. Hand held spreaders are available for hire or purchase in store or alternatively broadcast carefully by hand. A favoured method is to divide the required fertiliser into halves and then spread the first half in one direction and the other half at right angles to it. This way you can cover the area twice and achieve an even distribution. After spreading fertiliser the soil can be raked lightly and should be watered well until the soil is moist. Only apply when there is no wind so that the fertiliser lands only on the desired lawn area.
Selecting & Sowing Seed
There is a wide range of seed blends available to suit requirements or situation. A lawn seed which has proven highly successful in Whanganui is the Tui Superstrike range. It is a treated grass seed which offers protection from birds and contains insecticide to protect against insect damage, but it is not coated offering significant advantage in germination percentage and speed of grass establishment. This range of seed comes in a range of blends to suit different property conditions these blends include 'shady places', hot n dry', 'easy care', 'stadium blend' and 'hardwearing'. Information is available in the garden centre on these blends so you can decide which one suits your property best. A calm day is best when sowing grass seed, as seed is small and light. To assist in achieving an even sowing it is recommended that the same method is used as for applying fertiliser; divide the seed into halves and then spread the first half in one direction and the other half at right angles to it. After sowing the soil surface should be lightly raked, on light sandy soils a light covering of Tui Lawn Preparation Mix or similar is recommended to help to retain moisture and help to prevent seed washing away during watering or rain. The soil surface should be kept moist with light watering until seedlings have germinated and are well established. Water the lawn less frequently as the seedlings grow stronger, this encourages the roots to grow deeper.
It is important that young germinated lawn seed is kept moist otherwise it will die. If watering may be a problem it would be wise to sow your lawn in small sections over a few weeks. This may seem more intensive but it is better than having patchy germination over the whole lawn because of inadequate watering.
Establishment Care
Watering should be cut down to once a week and when grass is 3.5-4cm high it should be mown lightly and clippings removed. Ensure that your mower blades are sharp for a clean cut. The first mow should not remove more than 10 per cent of the height of the grass. After the third to fourth mow the cutting height can be gradually reduced. After the first or second mow the lawn should be fertilised with Tui Lawn Food, or Scotts Lawn Builder - slow release lawn fertiliser, using the recommended rates on the bag.
If flatweed such as dandelion, cape daisy and plantain and others are a problem spraying with Grosafe Lawnguard or Yates Turfix will provide good results. Putting in the hard work now will have you relaxing and enjoying your lawn in the months to come.
Have a good week.
Gareth Carter is general manager of Springvale Garden Centre