A good lawn is the pride and joy of many gardeners, and certainly a sweep of green is a wonderful contrast to flower borders and shrubs.
Good lawns require good preparation before sowing to ensure an even and well-grown result. Shortcuts taken in the preparation lead to a poor result and even more work later.
Prepare the ground
The fine grasses that we use in our lawns require good drainage, adequate moisture and a nutrient-rich soil to provide for grasses growing closely together. The minimum requirement is about 10cm of topsoil- if your garden cannot provide something close to this consider another surface rather than suffer a disappointing lawn.
Remove the topsoil, or spray it. Take the old sod and stack it as it is harder than the other soil you are working and can cause lumps in your new lawn. If you do not have time to work the soil over several weeks consider spraying the existing lawn cover to remove grass and weeds before cultivating, or even sterilising the soil. Chemical and organic methods of sterilisation can be used.
Give the soil a thorough and deep cultivation, either with a rotary hoe or by digging. Then go over it again several times 'scuffling' it to remove any remaining clods, eliminate weeds and consolidate the surface.
To improve drainage on very heavy soils add some coarse sand and mix in thoroughly.
If the soil is light, sandy or peaty, or simply insufficient, consider bringing in additional topsoil and adding this as a final top-layer over the existing soil which has been worked up. Make sure that the soil you obtain is of good quality and free from weeds such as couch grass (twitch) or oxalis as these are very difficult to eradicate.
Level the prepared ground. A levelling board will help with this. On a large lawn a light rolling can be beneficial but take care not to over-do it.
The centre of the lawn should be slightly raised to allow for surface water run-off and avoid the frustration of great puddles occurring. Dips and hollows also make mowing difficult and sudden changes in level can be hazardous!
You can add superphosphate (7g/m3) to promote good root and leaf growth, and sulphate of ammonia (14g/m3)as a ready source of nitrogen. Mix evenly into the soil with a rake several days before sowing the grass seed.
Compost can be mixed into the soil, but only if it is very well rotted. Bulky organic compost can pack down later, creating soft areas in the lawn later and resulting in hollows.
A top-dressing of NPK fertiliser can be beneficial three to four weeks after you have sown the lawn, spread lightly and evenly and gently water in.
The immaculate lawn emphasises design
Grass Seeds for Lawns
Select a seed mixture that is appropriate to your district, a good nursery will be able to advise you.
Check for drought resistance if you live in an area of low summer rainfall. Newer mixtures have been developed to reduce the watering requirement that having a traditional fine lawn demands in a hot dry summer.
Ryegrass makes a coarse lawn, grows vigorously and requires frequent cutting. However it will withstand heavier traffic and light shade better than finer grasses.
When added to a mixture of finer grasses ryegrass vigour means that it will overtake its neighbours.
The key to a beautiful lawn is in the preparation
A mixture of 25% Brown Top and 75% Chewings or Dawsons fescue is the classic lawn in the central and southern regions of New Zealand.
80% Dwarf Ryegrass, 15% Chewings Fescue and 5% Browntop will make a tougher lawn that will withstand hard wear, as well as being suitable in more northern and warmer districts.
Dry and coastal areas
100% Dwarf Ryegrass or 100% Amenity Turf Tall Fescue, or a mixture of 50% Improved Chewings Fescue and 50% Hard Fescue
100% Dwarf Ryegrass or a mixture of 50% Improved Chewings Fescue and 50% Hard Fescue
Sowing the Seed
You will need about 25/30g of lawn seed per m3. Sow evenly going both ways across you lawn. If you sow by hand work in metre wide bands, divide up the seed mixture into two and then sow one half moving lengthwise and the second width-wise. This should give an even coverage. Rake over gently.
Water lightly and keep moist during the germination period.
Mowing A New Lawn
Do not mow the grass until it is at least 7-10cm. Ensure that the mower blades are sharp as a blunt mower will drag your new lawn out by the roots! Set the mower high, say about 5 cm, for the first cut. Use a catcher to prevent the clipping smothering the new plants. Gradually lower the blades over the next several cuts to until they are about 2.5cm. This is the best height to maintain for your lawn.