Lawns
How to Manage a Lawn
by John Mason, Garden Writer and Principal of ACS Distance Education
Nearly everyone loves a beautiful lawn, even non gardeners.
It's one of the first things most of us think about creating in a new garden, perhaps because it's the easiest and often cheapest way to "finish off" a new home. Once the grass is down, it's much easier to keep mud and dust out of the house, it makes the property look much neater, and it's not so much of a hassle to let the children out to play, or to invite guests over for a visit.
Which Lawn
There are many different types of lawns; some which are easy to maintain, and others which require a lot of work. If you want the perfect lawn you will need to spend a lot of money and time, both to set it up initially, and on a regular basis, to keep it looking good. If you are prepared to accept something which doesn't always look quite as good, as long as the ground is covered with plants, then you can usually reduce costs greatly.
Consider:
- It is nearly always easier to grow a top quality lawn in sandy soil.
- Good drainage is essential for any lawn, particularly during wet weather. If the area is poorly drained, you will need underground drainage pipes and a good well drained topsoil to be sure of a quality lawn.
- Shaded areas are more difficult for producing good lawns, so those shaded parts of the garden may be better paved or planted as a garden bed.*Weeds will be a problem in any top quality lawn, particularly in rural areas or on new estates where weed seeds blow in from nearby paddocks.
- Be careful about bringing in contaminated topsoil (containing weed seeds, pests or salt). This is more likely if you buy cheaper soils or from less reputable suppliers.
- If you buy cheaper sod or instant turf, you are also likely to be buying grass which is contaminated with some weeds, even if you can't see them.
- Hardy, thick stemmed creeping grasses (e.g. Kikuyu or carpet grass) are often easier to grow and maintain as a lawn, but they rarely look as good as less hardy finer leaved grasses.
Creating a Lawn
There are many different ways of creating a new lawn.
The simplest and cheapest is to rotary hoe or level an area, let the weeds grow, then remove the weeds, either by spraying them or removing them in some way, or by cultivating them into the soil. On a larger property mowing the weeds may be quite acceptable. If you use a hardy ride on mower or tractor mounted slasher, the mower will gradually even out any bumps or undulations in the ground (particularly if there is a heavy roller bar at the back of the mower). If you spray any weeds (e.g. with roundup or zero) before cultivation, and sow grass seed after rotary hoeing, you will probably get a better quality lawn than by just mowing or slashing the weeds, then cultivating. You will almost certainly get a quicker cover of grass, particularly if the seed is raked in and kept well watered for the first few weeks.
A seed sown lawn can be rough if you are using hardy species such as rye, couch or clover, but for a quality lawn, the groundwork must be done well. If you plan a quality lawn, you need to eradicate all weeds first, remove any dead vegetation (i.e. old lawn grass, dead weeds etc., then establish a surface with sufficient slope to ensure good drainage, but not so much of a slope that the topsoil washes away.
The soil may require some form of improvement prior to laying the lawn. Both clay and sandy soils will benefit from the addition of well rotted compost or other organic matter. Poorly structured clay soils will benefit from the addition of materials that help 'break up' the clay into a crumbly structure, such as lime (for acid clay soils), gypsum, or commercial preparations. Some sandy soils resist the passage of water. These can be improved by the addition of wetting agents or well composted manures or commercial preparations, can be incorporated into the soil (i.e. rotary hoed or hand dug).
A good quality top soil is sometimes added to the surface of existing soil. This should ideally be incorporated into the top 7 - 10 cm of existing soil, so that the grass roots will be more likely to penetrate into the underlying soil rather than just spreading through the introduced topsoil.
Once the soil has been improved, it should be given a final level out, or raking so that you have a smooth, even surface, with no large clods present. This applies equally for soil that is to have sod laid on it, or to soil that will be sown with seed or runners.
A lawn grown from sod or instant turf can be easier and certainly faster to establish, but it can also be more expensive. Not all instant turf is good quality. Some is contaminated with weed seeds or bulbs and roots of weeds which sprout some time after planting. Some instant turf suppliers are rough in the way they handle their turf and though it may look good when it arrives, it may deteriorate and perhaps die soon after.
Instant turf usually comes with relatively few roots, and needs a good fertile, well drained soil to sit on top of, along with plenty of watering for the first few months to encourage the roots to move down and take hold. Experienced tradesmen can lay an instant lawn well and achieve a very level surface, but without proper care, the job can result in an uneven and patchy surface.
Sowing Seed
Once the soil has been prepared for sowing, determine (usually from the labelling on the seed packaging or suppliers instructions) the amount of seed you require to give a good coverage of the new lawn area. Seed can be easily sown by hand. Mixing the seed with several parts of fine sand to one part lawn seed will help you to get a more even spread.
Another way to obtain an even spread is to first sow the lawn using only half of the lawn seed, starting at one edge of the lawn and working your way across to the other side. Once this is done take the other half of the seed and start spreading from an adjacent side to where you first started and again work your way across the lawn (e.g. spread from north to south first then in an east to west direction). For large lawn areas it may be easier to break the lawn (and seed) into smaller sections for the purpose of sowing.
Avoid spreading seed in windy weather as grass seed is very light and can be readily blown into garden beds where it becomes a weed problem. Once the seed has been sown it should be lightly raked into the top soil so that it doesn't dry out, and so that birds don't eat it.
Rolling a Lawn
Heavy rollers are used on lawns to compact soil (where a hard surface is needed to play games such as cricket or tennis), or to level out an uneven surface. In the short term, rolling can be beneficial, but eventually, rolling can cause compaction, making drainage more difficult and having bad affects upon the general health of the turf.
Watering a New Lawn
Properly watering a new lawn is an art. If you have sown seed, it must be kept from drying out. Until the roots have sprouted and grown down into the soil, the plant can be very susceptible to dying from lack of water. Too much watering on the other hand may wash away valuable topsoil, and dislodge the young plant from where it is trying to take root.
Ideally, you should water lightly every few hours in hot weather and up to three times a day in mild weather. Freshly lain sod should also be kept moist (up to several times a day in warm weather), but will not generally require as frequent watering as newly sown seed.
Keeping a Lawn
Once you have a lawn, it is not a difficult job to keep it functional and looking relatively good, as long as it is mown regularly (not too low) and fertilized when it is growing fast.
Without regular fertilizing, weed problems are more likely to occur. If you want the perfect lawn though, you must be prepared to weed the lawn every 2-4 weeks (more often in warmer climates than cool), spray for pests or diseases as soon as they are detected, and aerate the lawn once or twice each year.
Aerating involves punching or drilling holes into the surface of the lawn and extracting soil. This allows air, fertilizer and water to penetrate deeper, prevents the build up of thatch (dry organic matter that acts as a physical barrier) and this way, keeps the grass roots healthier. Hand operated aerating forks are relatively inexpensive, and for a small area (e.g. 5-10sq. metres) and on soft soil, are easy to use, but for larger areas, a motorized aerating machine is preferable. Such machines can be hired with an operator from turf contractors in most larger cities.
Mowing
Lawns are frequently cut too low for their own health in Australia. Some turf varieties will tolerate lower cutting than others, though for most, the ideal height is at least 2cm tall.
Best Height to cut different lawns:
Variety |
Ideal mowing height (Approx.) |
Bentgrass |
0.5cm (on a bowling or golf green) |
Bentgrass |
1cm (in a garden lawn) |
Kentucky Bluegrass |
3.5cm |
Creeping Fescue |
3.5cm |
Tall Fescue |
6cm |
Perennial Ryegrass |
3cm |
Bermuda couchgrass |
2cm |
Buffalo Grass |
3cm |
Kikuyu |
2cm |
If you mow too close, you will scalp the grass in places (i.e. shear it off at ground level or lower). This is a particular problem if the lawn surface is uneven or bumpy, if you don't mow often enough, or if the thatch is thick and spongy (so the mower sinks into the thatch). Scalped turf looks ugly and can die allowing weeds to invade.
The frequency of mowing depends on the time of year (rate of growth), the height of cut and the quality of lawn you seek. If you want the best quality lawn, you must mow more often.
The pattern of mowing will affect the way the turf plants grow. If you mow in the same direction every time, the grass will tend to lie over and grow in the direction which you mow. This gives an affect which might not be overly obvious, but it can affect the way a golf ball rolls, or the subtle appearance of a turf. Alternating the direction of mowing, or cutting the grass higher will eliminate this affect.
Grass Clippings can be left lying on the lawn if you mow often enough, but not if they are so bulky that they lie in lumps on the surface and smother patches of grass. If your clippings are to be collected and used in compost or as a mulch on garden beds, be sure that they don't contain any weed seeds. Couch grass lawns can produce viable seed heads within a week of mowing in warm weather.
Mowers
There are two main types of mowers used in home gardens.
The reel or cylinder mower cuts grass clean like a pair of scissors, hitting the grass at an angle and wedging it against a metal plate.
The rotary mower cuts the grass by hitting it at a 90 degree angle with a sharp blade mounted on a rotating horizontal plate. If the blades are kept very sharp, and the grass is not too soft, this cut can also be sharp, but otherwise, a rotary mower can tear grass leaving a jagged edge which can cause the grass to brown off a little. This is not as healthy for the grass, and often leads to rotary mown lawns loosing their lush look within a few days of being cut.
Both types of mowers can be powered by either petrol or electric motors. Hand powered versions of the cylinder mower are also available. These are the most inexpensive mowers to purchase, but are really only practical for a relatively even surface and small areas (e.g. ideal for people in a villa unit). Electric powered mowers are cheaper than petrol mowers, and for anyone who is not mechanically minded these may be more reliable. The main disadvantage is that an electric mower has a power chord, which needs to be kept behind the mower at all times. It is dangerous to run over. Electric mowers often don't have the same amount of power as a petrol mower either, so if you plan to mow long grass and work your machine hard, go for a petrol machine.
Repairing a Lawn
All sorts of things can go wrong with lawns, causing patches of grass to die, or simply to lose their vigour. Often the best treatment is to dig out that section of the lawn and replace it as you would do when planting a new lawn. Any soil and unhealthy grass which is removed should be thrown away. If it is diseased, take it to the tip or burn it.
For areas that are not severely damaged, aeration, fertilisation and correct watering and mowing will soon encourage a healthy lawn to grow.
Learn more about lawns
For the home gardener or someone maintaining gardens, there is nothing quite like a beautifully maintained lawn, particularly in the summer months. Likewise, if turf is being used for sporting purposes it needs to be well looked after to be suitable for its purpose but to also ensure that its health is maintained.
ACS offer specialist courses in turf care and maintenance which have been developed by horticultural specialists. They are available to start at any time and are studied by distance learning. The courses available include:
Turf Care
Turf Grasses
Sports Turf Management
If you are looking for broader based courses such as Garden Maintenance, or are looking to study a greater number of subject areas, we offer higher level qualifications in Horticulture and these can be found by following the link to the directory at the bottom of this page.
If you are looking to study whether it be for personal interest or for your professional development, our specialist horticulture tutors will be happy to answer your questions and help outline the different course options available to suit you.
[01/09/2024 16:43:57]
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