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Lawn and Turf Maintenance
Introduction
This article was written specifically for the management of cool season grasses in Auckland, New zealand, which is warmer than in Germany where I lived for many years and gained most of my experience in managing cool season grasses, but the basic principles apply for both regions.
Much of what has been written in this article also applies for the management of warm season grasses
This article was written specifically for the management of cool season grasses in Auckland, New zealand, which is warmer than in Germany where I lived for many years and gained most of my experience in managing cool season grasses, but the basic principles apply for both regions.
Much of what has been written in this article also applies for the management of warm season grasses
Following the establishment of your lawn, the focus now changes to Turf Management. Contrary to popular belief, Turf Management does not need to be a daily chore, although the amount of work necessary depends on the quality of lawn desired. For many only minor changes to existing Turf Management practices is all that is required to have a top quality lawn.
Mowing
Mowing is the most important
task
undertaken. Make sure the mower blades are kept sharp at all
times
as blunt blades will damage the grass leaves and give a poor quality
unsightly
cut. The commonly adopted approach to grass cutting is that of scalping
the
lawn at periodic intervals, (i.e. setting the mower too low) this
causes
serious damage to turf grasses, thus negatively affecting the quality
of
the lawn. This practice in conjunction with insufficient or
inappropriate
fertilizing is one of the main reasons why lawns become sparse and
dominated
by weeds. A mower with blunt blades, especially a rotary type mower
that
cuts lawn by impact does considerable physical damage to the grass leaf
which
increases the grass plant's susceptibility to fungal and bacterial
attack,
increases moisture loss and gives the lawn a ragged white look. The
best
mowers to use on fine turf are well set reel mowers that slice cleanly
through
the grass leaf. Some grasses like Rye grass and Blue grass don't mind a
rotary cut but the fine turf grasses like Bent (Browntop) and Fescue
prefer a reel mower. Reel mowers give the finest cut and also roll the
lawn smooth.
Mowing Height
Each turf grass species has its
own optimal mowing height. When mown regularly within the correct
height range, a uniform dense turf cover is encouraged which limits the
opportunity for weeds to establish. Conversely, mowing
too low or too high thins the turf, which allows bare areas to develop,
in time these areas become colonized by weeds. As a rule of thumb for
home lawns a height between 25- 40 mm gives the best results. In shady
areas the lawn should be allowed to grow a little longer. Short lawns
look neater however the grass plants have shorter roots systems, and
suffer more environmental stress. This means that short lawns require
very
careful management, in particular watering, fertilizing and mowing.
Increasing the height of cut under stress conditions in particular
during
summer drought periods is a good management practice, which helps to
maintain a healthy lawn.
Mowing Frequency
The rule of thumb is to remove
no
more than 25% of the grass plant leaf at any one time. Scalping
(removing all or most of the leaf and the growing points, as well as
parts of the stem) severely damages or kills the turf grass plants thus
allowing weed seeds the opportunity to germinate and to establish
themselves in the lawn, this bad management practice provides the
opportunity
for weeds to better compete.
Mowing height and frequency
will depend on:
- The specie and variety of grass. Creating Turf lawns are mostly of fine leafed Rye, Fescue and Bent grass (Browntop) or a monoculture of one species.
- Time of the year (for example, growth is more vigorous in Autumn/Spring than in Winter.
- Mowing height and frequency is dependant on the use the lawn is to be put to as well as personal preference.
The more frequently the lawn is mowed the better the quality of the lawn produced
If you wish to improve the
appearance of the lawn for a special event, the best result will be
achieved through an increase in mowing frequency not a lowering of
height. This may involve mowing up to three times per week.
This increase in frequency should begin at a minimum two weeks before
the event.
Lawn clippings
Grass clippings can be left on
the lawn after cutting, rather than removing them. The clippings
decompose quickly, returning nutrients to the soil within weeks of
mowing.
The macro elements contained within the clippings comprise of nitrogen,
phosphorus and potassium at ratios of 5:2:3, respectively. Trace
minerals are also present. The amount of nitrogen returned to the
soil is as much as 88 kg/ha. Since nitrogen is the most expensive
component
of all lawn fertilizers, it pays to leave clippings.
Clippings also enhance the habitat for beneficial soil micro-organisms. Earthworms ingest the clippings at night, further increasing the aeration and fertility of the soil, and maintaining a base that allows the lawn to feel springy when walked on. If the grass clippings are removed, worms will migrate to other more favourable habitats this will negatively influence soil structure and fertility.
Whether to return or remove the clippings or to return them to the soil is a personal choice.
I personally believe that it is a good environmental practice to allow the grass clippings to remain onsite.
Clippings also enhance the habitat for beneficial soil micro-organisms. Earthworms ingest the clippings at night, further increasing the aeration and fertility of the soil, and maintaining a base that allows the lawn to feel springy when walked on. If the grass clippings are removed, worms will migrate to other more favourable habitats this will negatively influence soil structure and fertility.
Whether to return or remove the clippings or to return them to the soil is a personal choice.
I personally believe that it is a good environmental practice to allow the grass clippings to remain onsite.
There are good reasons in favour of both options.
Where clippings are returned to the soil the advantages include:
- Mowing is easier
- Mowing is (generally) cheaper in particular where contractors are employed
- Nutrients are recycled to the lawn
- It is a good environmental practice to do so
The disadvantages of clipping return include:
- The finish may not be as good
- Disease could under certain circumstances be enhanced
- On weedy lawns, weed seed is returned to the soil
- Where clippings are too thick, the turf can become smothered allowing weeds to establish.
- A possible Increase in thatch build-up. (Thatch is an accumulation of dead leaf and stems and shoot mass encountered on well used lawns that experience large amounts of traffic, thatch reduces or prevents the penetration of water into the soil and a reduced gas exchange to the root zone). Thatch is seldom encountered on home lawns.
Mowing a little less frequently and raising the height of the cut during hot periods will reduce moisture loss.
- Disease could under certain circumstances be enhanced
- On weedy lawns, weed seed is returned to the soil
- Where clippings are too thick, the turf can become smothered allowing weeds to establish.
- A possible Increase in thatch build-up. (Thatch is an accumulation of dead leaf and stems and shoot mass encountered on well used lawns that experience large amounts of traffic, thatch reduces or prevents the penetration of water into the soil and a reduced gas exchange to the root zone). Thatch is seldom encountered on home lawns.
Mowing a little less frequently and raising the height of the cut during hot periods will reduce moisture loss.
Fertilizing
The grass plants, which make
lawns as with all living organisms, require nutrients to grow and to
be healthy. Regular applications of fertilizer supply the required
nutrients thus ensuring vigorous healthy grass plants and a top quality
lawn. The nutrients essential for growth within the soil are nitrogen
(N), phosphorus (P), potassium (K) and iron (Fe). As a result of lawn
culture certain essential plant nutrients are lost to the system,
due to the removal of grass clippings, leaching of nutrients out of
the root zone as well as losses of nitrogen to the atmosphere. Nitrogen
deficient grass is yellow-green, and lacks vigour. Nitrogen produces
deep green leaves, rapidly growing leaves and shorter roots. Phosphorus
facilitates metabolic functions plus energy storage and use. Potassium
is used to create cell components, and it helps regulate respiration
and transpiration. It helps the plant grow, withstand environmental
stress and resist disease. Fertilizers should contain N, P and K. where
possible select a balanced fertilizer that contains a mixture of slow
and fast release N. This allows the lawn to green up with 2-3 days and
stay green for several weeks.
Iron can be used to control moss and some broad-leaved weeds. Iron
darkens
the grass, making it appear greener without stimulating growth.
Always use a balanced lawn fertilizer.
Frequency of application
The general rule is that frequency should be such that turf density and colour is maintained. Obviously the exact programme will be influenced by many factors, such as:
The general rule is that frequency should be such that turf density and colour is maintained. Obviously the exact programme will be influenced by many factors, such as:
- grass type
- atmospheric conditions
- soil type, i.e. sandy soils will require lighter more frequent dressings than loam/clay soils
- whether clipped are moved or not
- amount of wear received (high traffic areas require more regular dressings)
If your lawn begins to turn
yellow then it may need fertilizer for chlorophyll synthesis to occur.
However, as with most things, over fertilizing may result in problems (thatch, disease) and ultimately an unhealthy and difficult to maintain lawn.
As a general rule two main applications of a good balanced lawn fertilizer with a higher potassium (K) content in the spring and autumn and if needs be one or two light applications of a balanced fertilizer with a higher nitrogen (N) content during the Summer months will produce a high quality lawn, however be careful too much nitrogen applied in summer may stimulate lush growth and encourage diseases.
However, as with most things, over fertilizing may result in problems (thatch, disease) and ultimately an unhealthy and difficult to maintain lawn.
As a general rule two main applications of a good balanced lawn fertilizer with a higher potassium (K) content in the spring and autumn and if needs be one or two light applications of a balanced fertilizer with a higher nitrogen (N) content during the Summer months will produce a high quality lawn, however be careful too much nitrogen applied in summer may stimulate lush growth and encourage diseases.
Fertilizer Application
Apply fertilizer uniformly to avoid variations in growth and the risk of killing the grass due to toxic doses. Never apply fertilizer by hand always use a mechanical fertilizer spreader, i.e. a Scotts spreader, which can be purchased from most hardware and garden shops. For even application when applying the fertilizer divide the fertilizer into two batches, and apply half in one direction and the rest at right angles to it. If using a spinning disc or broadcast spreader, set the machine to half the application rate and make adjacent runs at half the distance apart of the machine's spread.
Apply fertilizer uniformly to avoid variations in growth and the risk of killing the grass due to toxic doses. Never apply fertilizer by hand always use a mechanical fertilizer spreader, i.e. a Scotts spreader, which can be purchased from most hardware and garden shops. For even application when applying the fertilizer divide the fertilizer into two batches, and apply half in one direction and the rest at right angles to it. If using a spinning disc or broadcast spreader, set the machine to half the application rate and make adjacent runs at half the distance apart of the machine's spread.
1. Always apply a known weight of fertilizer to a known area at the recommended rate, to avoid fertilizer toxicity.
2. Avoid applying fertilizer in the heat of the day.
3. Never apply fertilizer to a lawn that is under moisture stress.
4. Always irrigate after applying fertilizer
To prevent corrosion to metal parts of the applicator, wash the applicators with water after use.
Watering
The use of irrigation is primarily to supplement deficiencies in rainfall, a good automatic system can be used to maintain the lawn in top condition throughout the summer. However, care is required, as poor irrigation management in particular over watering can create problems.
The use of irrigation is primarily to supplement deficiencies in rainfall, a good automatic system can be used to maintain the lawn in top condition throughout the summer. However, care is required, as poor irrigation management in particular over watering can create problems.
Watering during establishment
As a general guide irrigate early morning again for a short period at mid-day and again in the early evening
There are cost effective water timers and sprinklers available from retail outlets.
Quantity
When irrigating, completely wet the root zone rather than just wetting the surface. To avoid wastage, water should be applied at a rate so that ponding is avoided. This may require several short bursts of watering rather than a single irrigation cycle.
Watering after establishment
Turf grass is a relatively low user of water. Enough water to completely wet the root zone must be applied at each watering. The frequency of watering will be determined by atmospheric conditions and the water retention properties of the soil. Irrigate before the first signs of wilting to avoid damage to the lawn.
Weeds
Weeds are unwanted plants that will colonize your lawn if you engage in bad management practices, for instance, incorrect mowing height and frequency, insufficient or inappropriate watering, the lack of regular applications of or too much fertilizer, or to a much lesser extent insect or disease attack.
When the turf looses its density and uniformity an open sward develops that leaves it wide open to colonization by unwanted weeds. Weeds in turf grasses can be very effectively controlled with the use of herbicides and by implementing a good turf management program.
To correctly apply herbicides is a skilled job that requires a good understanding of their application and mode of action as well as the correct identification of the particular weed to be eradicated. There are many herbicides that can successfully remove weeds, both broad leaf and weed grasses from lawns, however if you are not experienced in turf care, consult an expert.
When irrigating, completely wet the root zone rather than just wetting the surface. To avoid wastage, water should be applied at a rate so that ponding is avoided. This may require several short bursts of watering rather than a single irrigation cycle.
Watering after establishment
Turf grass is a relatively low user of water. Enough water to completely wet the root zone must be applied at each watering. The frequency of watering will be determined by atmospheric conditions and the water retention properties of the soil. Irrigate before the first signs of wilting to avoid damage to the lawn.
Weeds
Weeds are unwanted plants that will colonize your lawn if you engage in bad management practices, for instance, incorrect mowing height and frequency, insufficient or inappropriate watering, the lack of regular applications of or too much fertilizer, or to a much lesser extent insect or disease attack.
When the turf looses its density and uniformity an open sward develops that leaves it wide open to colonization by unwanted weeds. Weeds in turf grasses can be very effectively controlled with the use of herbicides and by implementing a good turf management program.
To correctly apply herbicides is a skilled job that requires a good understanding of their application and mode of action as well as the correct identification of the particular weed to be eradicated. There are many herbicides that can successfully remove weeds, both broad leaf and weed grasses from lawns, however if you are not experienced in turf care, consult an expert.
When applying herbicides always:
- Read the manufacturer's instructions on the label
- Follow all safety and application instructions
- Wear safety equipment as required
- Use a calibrated sprayer
Insect Pests
The most frequent insect pests encountered in New Zealand are;
Grass Grub, Porina caterpillar, Stem Weevil
All three are aggressive turf pests that require specific insecticides to eradicate therefore accurate identification of the insect pest is important.
As with weed control, there is a large range of insecticides on the market.
When applying insecticides always:
- Read the manufacturer's instructions on the label
- Follow all safety and application instructions
- Wear safety equipment as required
- Use a calibrated sprayer
When in doubt always consult an expert.
Ecoman Sports Turf and Lawn Expert
I
have considerable
experience with establishing and managing both warm season as well as
cool
season grasses which has been gained in
Sports Turf Construction Experience
My
sports turf construction
experience includes the construction of many sports fields for
football, rugby
hockey and cricket, golf course greens, bowling greens, turf wickets in
Amenity Turf Construction Experience
Most
of my amenity turf
construction experience comes from over 28 years constructing and
maintaining
parks and gardens for the Durban Parks Department, I also gained
valuable
experience as a private contractor constructing parks and establishing
cool
season grasses mostly for the North Shore City Council in Auckland New
Sports Turf and Amenity Turf Maintenance Experience
Most of my sports turf and amenity turf maintenance experience comes from the maintenance of a large number of parks, sports fields, road verges etc that were under my direct care as a horticulturist then later as a horticultural manager during the 28 years that I was employed by the Durban Parks Department
Domestic lawn Establishment and Maintenance Experience
My
domestic lawn
establishment and maintenance experience has been gained on warm season
grasses
in
For
a number of years I
over seeded portions of my own domestic lawn in
Academic Achievements
Certificate in
Turf Grass Management
(Cum Laude)
Best Student Turf
Grass Management
Association 1984
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