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
At this stage when your new lawn has a 5-10mm layer of loose soil it is time to apply a pre-seeding dressing of fertiliser. Use Tui Lawn Fertiliser at the rate for sowing new lawns (prescribed on the bag).
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 and sowing seed
There is a wide range of seed blends available to suit the particular requirements or the 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 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 is recommended. This will help to retain moisture and 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 less frequently as the seedlings grow stronger — this encourages the roots to grow deeper.
It is very 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 mow lightly and remove clippings. 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 or fourth mow the cutting height can be gradually reduced. After the first or second mow the lawn should be fertilised with Tui Lawn Food, using the recommended rates for new lawns.
If flatweed such as dandelion, cape daisy and plantain and others are a problem spraying with 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