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Pest / Insect
Control | Shade
| Watering | Mowing | Fertilization
| Top Dressing | Scarifying
Lawn Grubs
Lawn grub season traditionally extends from October
through to March, but varies slightly with seasonal conditions.
It is no coincidence that the season peaks (usually after Christmas) with
the coming of our thunderstorms and increased humidity levels. For that
is when the best growing conditions for our lawns are provided, with lots
of new growth and fresh leaf for the grubs to feed on.
Did you know that the life cycle of the lawn grub can be as short as fourteen
days (2 weeks) at the height of the season. This means that regular spraying
is needed to control the grubs to prevent their numbers from increasing
to plague proportions.
There are quite a few different varieties of grubs which attack lawns.
All are laid by small moths which flutter through and across the lawn
laying their eggs as they go. These eggs can hatch within days if climatic
conditions are right. Alternately, they can also remain dormant in the
lawn till the next season.
One easy way to check to see if you have grubs is to place a damp hessian
bag or similar item on top of the lawn overnight. When the bag is lifted
the next morning the grubs will be sitting on top of the leaf still actively
feeding under the protection of the bag.
It is of the utmost importance to address the problem of grub infestation
quickly, particularly if the lawn has been newly laid. For if the lawn
is severely damaged before it has had a chance to establish a strong root
system, large dead areas will occur!!!
There are many insecticides on the market to control lawn grub. All will
work efficiently if used correctly as per the directions on the bottle.
Best results will be obtained by using a pressurised spray tank, covering
the lawn in a controlled even spray.  For
those who prefer, a nontoxic organic spray is now available. It is wise
to remember that sprays will only last three days at best before u.v.
rays destroy it. Also watering will dissipate the spray quickly.
The most common signs of infestation are:
1. Birds feeding on the lawn.
2. Patchy or discoloured areas of lawn.
This is caused by the grubs chewing off most of the leaf leaving the stalks
and under storey of the plant exposed.
3. Red and blue wasps hovering over the lawn.
These wasps are looking for grubs and actually sting the grub and lay
their eggs in the body of the grub. They will not, however, eradicate
enough of the grubs to solve the problem. Rather, both the wasps and grubs
tend to increase their numbers until the lawn is destroyed. The grubs
will then "move camp" looking for new plants to feed on (including
gardens).
If the problem has been discovered too late
and the damage has already occurred :
1. Spray immediately and leave overnight.
2. Fertilize well with a good all round fertilizer.
3. Lightly top-dress
4. Water daily.
It is important to encourage the lawn to recover as quickly as possible,
as once the cover of the grass has been lost, weeds will quickly move
in and start to take over.
Obviously, it is far better not to allow the problem to develop at all,
so keep a watchful eye and remember ....
If in doubt - spray anyway
African Black Beetle- A major scarab pest
of warm region. The adult beetle invades turf every spring causing disruption
to surfaces from tunneling and bird damage. The larvae stage is a white
curl grub that does significance damage to turf by feeding on the root
system,causing large patches to brown off and die during summer. Dead
turf can often be lifted like a carpet as every root has been severed.
Treatment involves using pesticides ( Chlorpyrifos,Baythroid,Merit,Oftanol)
washed into the soil profile. Assist recovery of turf by raking out and
removing dead material, fertilizing and light top dressing. Water frequently.
TURFGRASS ... MADE IN THE SHADE.
Growing turf in the shade is a major problem for
many homeowners because an estimated 20 to 25 percent of all grassy areas
are shaded to varying degrees. While it's not always advisable to even
try to maintain beautiful grass in all shaded conditions, the not-for-profit
Turf Resource Centre recommends the following five steps to maximise turf
in shade areas.
Step 1:
Make an informed choice about the likelihood of success:
Even the most shade tolerant grasses need at least 50 percent sunlight
or a minimum of four hours of sunlight daily to survive. Pruning a tree's
canopy and it's lower 8 to 10 feet of limbs will allow more sunlight to
reach the ground, but it may be destructive to the tree or spoil its natural
appearance. If you can't achieve minimal sunlight for grass, switch to
a shade tolerant ground cover.
Step 2:
Select the most shade tolerant grass species possible for your climate:
Not all grasses are created equal, especially when it comes to light requirements.
Various independent researchers have concluded the following rankings
for shade tolerance:
For warm season grasses (starting with the most tolerant) - St. Augustine
grass(ST85); Centipede grass is similar to St. Augustine]; Bahiagrass;
Zoysiagrass; Carpetgrass; Bermudagrass.
For cool season grasses (most shade tolerant first) - Fine fescue; Bentgrass;
Rough bluegrass; shade tolerant cultivars of Kentucky bluegrass; Tall
fescue; Perennial ryegrass; and non-shade tolerant cultivars of Kentucky
bluegrass. (Consult with a Landscaper, top-quality garden centre or turf
producer in your area for their specific cultivar recommendation that
should also include considerations for maximum and minimum temperatures
and disease factors.)
Step 3:
Select trees that compliment turf's presence:
Trees with dense canopies and/or shallow root systems create problems
for turf. Try to avoid turfing under densely canopied trees and for trees
with shallow root systems, consider raising the soil levels a little to
allow the turf roots a chance to compete.
Step 4:
Adjust turf maintenance practices to maximize the chances of success:
-Water early in the morning and infrequently, applying enough water at
a single time to
moisten the soil five to eight inches deep. This approach will reduce
the potential outbreak of turf diseases that thrive in damp shady areas.
-Mow at a minimum height of 2,5 to 3 inches, with a sharp blade, removing
no more that the top one-third of the grass blades. Most heavily shaded
grass grows more upright and stringy to increase the leaf surface and
capture any available sunlight. Cutting at a greater that normal height
allows this phenomenon to continue.
-Fertilize at half-dose rates of nitrogen, compared to the sunnier areas
of the Iawn and increase potassium rates. Nitrogen encourages succulence
that can decrease wear tolerance and increase disease susceptibility,
while potassium can improve both conditions.
-Herbicide applications should rarely be used because this will place
yet another stress on an already less than ideal grass plant.
Step 5:
Reduce heavy use of the shaded grass areas:
As fragile as shaded grass plants are, it doesn't take much to tear out
their shallow root systems, or otherwise damage the plant beyond its ability
to recover. Limiting heavy use of these areas will give the grass more
opportunities to battle the other shortcomings it is contending with already.
One final, although practically limited suggestion, is to simply plan
to re-turf heavily shaded areas every few years, as part of the yard's
overall maintenance plan. Stripping off the nearly nonexistent grass and
replacing it with dense, mature turf can immediately refresh a shady area.
Accepting the fact that even the most shade tolerant grasses will thin
out over two to five years and planning to re-turf at that point can accomplish
a homeowner's dream.
Watering Turf: How, When & How Much
Water is essential to all life…… too little water and we die,
too much and we drown. The same is true of the grass in our lawns. Water
makes up 70% to 80% of the weight of our lawn grasses and the clippings
alone are nearly 90% water, Many newly laid lawns are destroyed or damaged
by not watering enough or quickly enough.
The first watering of newly installed turf is the most important. Begin
watering immediately after the installation of the new turf. The first
watering establishes how well the grass will perform in the years to come.
When to Water your New Turf
It is essential to begin watering your new turf within a half hour after
it is laid on the soil. Apply at least 1 inch (2.5 cm) of water so that
the soil beneath the turf is very wet. Ideally, the soil 3 to 4 inches
(7- 10 cm) below the surface will be moist.
Watering Tip #1:
Pull back a corner of the turf and push a screwdriver or some other sharp
tool into the soil. It should push easily and have moisture along the
first 3 or 4 in. (7 to 10 cm), or you need to apply more water.
Watering Tip #2:
Make absolutely certain that water is getting to all areas of the new
lawn, regardless of the type of sprinkling system you use. Corners and
edges are missed by many sprinklers and are particularly vulnerable to
drying out faster than the center portion of the lawn. Also, areas near
buildings dry out faster because of reflected heat and may require more
water.
Watering Tip #3:
Run off may occur on some soils and sloped areas before the soil is adequately
moist. To conserve water and ensure adequate soak-in, turn off the water
when run-off begins, wait 30 minutes and restart the watering on the same
area, repeating as needed.
For the next two weeks (or until the turf is well rooted), keep the below-turf
soil surface moist with daily (or more frequent) watering of approximately
one-quarter inch (0.6cm) each. Especially hot, dry or windy periods will
necessitate increased watering amounts and frequency.
Watering Tip #4:
As the turf begins to knit it's new roots into the soil, it will be difficult,
impossible and/or harmful to pull back a corner to check beneath the turf
(Watering Tip#1), but you can still use the sharp tool to check moisture
depth by pushing it through the turf and into the soil.
Watering Tip #5:
Water as early in the morning as possible to take advantage of the daily
start of the grass's normal growing cycle, usually lower wind speeds and
considerably less loss of water because of the high temperature evaporation.
Watering Tip #6:
If the temperature approached 100(37 C), or if high winds are constant
for more than half of the day, reduce the temperature of the turf surface
by lightly sprinkling the area. This does not replace the need for longer,
deeper watering, which will become even more critical to continue during
adverse weather conditions.
During the remainder of the growing season, most lawns will do very well
with a maximum total of one inch of water a week, coming either from rain
or applied water. Soil conditions may dictate that the amount be applied
in two settings, approximately two to three days apart. This amount of
water, properly applied is all that is required for the health of the
grass, providing it is applied evenly and saturates the underlying soil
to a depth of 4 to 6 in. (10 to 15 cm).
Watering Tip #7:
Infrequent and deep watering is preferred to frequent and shallow watering
because the roots will only grow as deeply as their most frequently available
water supply. Deeply rooted grass has a larger"soil-water bank"
to draw moisture from and this will help the grass survive drought and
hot weather that rapidly dries out the upper soil layer.
Proper watering techniques are a critical aspect of lawn watering,
equal in importance to the issues of when to water and how much to water.
Here are several key factors to proper technique:
Avoid hand sprinkling because it cannot provide the necessary
uniformity. Most people do not have the patience, time or "eye"
to adequately measure what is being applied across any large areas of
lawn. The only possible exception to this guideline would be the need
to sprinkle the surface of the grass to cool it, or to provide additional
water near buildings or other heat-reflecting surfaces.
Understanding the differences between sprinkler designs because
each type has its advantages and disadvantages. Its proper use will be
determined by the type of sprinkler you select.
In-Ground systems require professional design and installation
and they require routine adjustments and regular maintenance to be most
efficient and effective. The greatest mistake made with most in-ground
systems is the "set it and forget it" philosophy that fails
to account for the changing seasonal water requirements to maximise turf
growth or even allowing the system to operate during or following a multi-inch
rain storm. Another frequent problem is when heads get out of alignment
and apply water to the sidewalk, street or house-siding, rather than to
the lawn. The potential for evaporation loss is reduced and trees, shrubs
and other plants do not block the pattern (or very noticable if they do).
Hose-End Sprinklers range in complexity, cost and durability,
but are highly portable and can provide uniform and consistent coverage,
when properly placed on the yard and adequately maintained. Sprinkler
that do not throw the water high into the air are usually more efficient,
as are larger drop generators because prevailing winds are less disruptive
of distribution patterns, the potential for evaporation loss do not block
the pattern (or very noticeable if they do).
Several times during the growing/watering season. Routine maintenance
is important to check for blocked outlets, or mis-aligned sprinkler heads,
regardless of the sprinkler design.
Watering Uniformity
Verifying watering uniformity can be accomplished with a very simple
and inexpensive method that uses only four to six flat bottomed, straight
sided cans (tuna fish, cat food, etc.), a ruler and a watch.
Follow these steps:
Step #1: arrange the cans at random distances away from any sprinkler,
but all within the area you assume is being covered;
Step #2: run the sprinkler for a specific amount of time, say
half an hour OR run the water till a specific amount of water is in at
least one can, say 0.5in. (1.3cm).
Step #3: measure the amount of water in each can, checking uniformity.
Some variation is expected, but a difference of 25-30% or more between
any two cans must be addressed by replacing or adjusting the sprinkler
or relocating the system.
This measuring method should be used across an entire lawn that has an
in-ground irrigation system to assure maximum coverage and uniformity.
Watering difficult areas such as slopes and under trees requires some
special attention to achieve maximum benefit and a beautiful lawn.
For slopes, see (Watering Tip #3)
For Areas Near and Under Trees you need to know the water requirements
for the specific trees, as well as for the grass. Despite having deep"anchor"
roots, trees take up moisture and nutrients for the top six inches of
soil...the same area as the grass, Trees and grass will compete for water.
Watering sufficiently for the grass may over-water some varieties of trees
and under water-others. A common solution is not to plant grass under
the drip line of the trees, but rather use that area for perennial ground
covers, flower beds or mulch beds
How Much Water Is Needed And Applied
The amount of water your lawn requires and receives will determine its
overall health, beauty and ability to withstand use and drought. Keep
in mind that too much water can ruin a lawn just as fast as too little
water.
One inch (2.5cm) a week is a "watering rule of thumb" suggested
for most lawns; however, this will vary between different turf species
and even among cultivars of a species. There will also be varying water
requirements for seasonal changes and still more differences brought about
because of different soil types.
Look at your lawn to determine its water needs. Grass in need of water
will have a heavy grey-blue cast, rather than a blue-green or green colour.
Also, foot prints will completely disappear within a few minutes. Inspecting
your lawn frequently will help you detect water requirements and to avoid
over- or under-watering.
Verify water quantities with the same measuring can method mentioned
above, except you will want to note the TIME it takes to collect a specific
amount of water. For example if 0.25in. (0.6cm) collects in 30 minutes,
you can easily calculate that it will take one hour to apply 0.5in. (1.3cm)
of water and two hours to apply 1 in. (2.5cm) of water.
Water Timers can help provide consistence and even be programmed
to turn on and off when no one is awake or at home. Some timers measure
just the amount of time water is flowing through the device, while other
measure the number of gallons of water flowing through it. Read the timer's
directions to determine how your operates.
Mowing is often seen as a chore to be put off for as long as possible,
however, mowing is a critical factor in the ongoing maintenance and finish
of a good lawn. Mowing frequency, height of cut and even the type of mower
used will all produce different finishes to the lawn.
It is important to realise the benefits of mowing frequently. Frequent
mowing tends to thicken the lawn, conserving soil moisture and providing
greater competition against weed invasion. Frequent mowing also removes
seed head on any weeds present in the lawn and therefore helps to reduce
the problem of spreading weed and seed.
When mowing, never remove more than 1/3 of the leaf blade at any one
time as this stresses the plant.
New lawns should be mowed as soon as the turf has rooted in properly.
This time frame will vary according to the variety and also the time of
year. As a general rule of thumb - between the second and third week after
installation.
The first mow should be done on a high setting so as to just "tidy" the
lawn. Continue to mow every three days or so and gradually reduce the
height to the level you intend to maintain the lawn at. For couchgrass,
18-25mm is a good height. Lift the mower slightly for winter mowing height.
A well-planned, reasonable fertility program is a basic part of proper
lawn maintenance. Lawngrasses that are under-fertilized tend to be thin
with poor color. Lawns that are over-fertilized, especially with high
levels of soluble nitrogen fertilizer, tend to have thatch problems and
are more prone to insect and disease damage.
The goal of a good fertility program is to produce a reasonable amount
of top growth, but not at the expense of root growth or carbohydrate storage.
A good root system is the key factor to a healthy lawn.
Nitrogen (N), Phosphorus (P), Potassium (K).
Lawn fertilizers typically contain these three nutrients, although other
nutrients may be included in small amounts. The three numbers on the fertilizer
bag represent the percentages of N, P, & K-in that order. The back
of the fertilizer bag should show the guaranteed analysis. Always follow
the recommended application rates suggested by the manufacturer on the
bag.
The grass plant needs more nitrogen than any other nutrient.
Nitrogen is part of the chlorophyll molecule and helps give the lawn its
deep green color. Nitrogen also tends to promote high leaf growth rates
at the expense of root growth. Phosphorus is responsible for the energy
transfer systems in the plant and is generally required in much smaller
amounts than nitrogen or potassium on an established lawn. The exception
is for newly established lawns by seeding, sodding, or sprigging, when
the need of phosphorus is higher in the new plant. Potassium has a lot
to do with good cell wall development and the plant's ability to withstand
stress, disease, and insect damage.
Look for slow-release forms of nitrogen.
The two basic forms of nitrogen that can be used as a fertilizer are organic
and inorganic. The most commonly used inorganic forms of nitrogen in fertilizers
are ammonium nitrate and ammonium sulfate. Both are soluble, quickly available
forms of nitrogen and both tend to produce a fast increase in leaf growth
for a fairly short period of time. These are cheaper forms of nitrogen
and are found in less costly fertilizers.
More and more, the slowly soluble or slow-release organic forms of nitrogen
are being recommended by turf experts. These include sulfur-coated urea,
ureaformaldehyde, I.B.D.U., methylene urea, natural organics, and resin-coated
urea. These tend to produce a lawn with good color without excessive leaf
growth. They are designed to meter-out the nitrogen over a longer period
of time. The slow-release forms of nitrogen are more costly than the soluble
quick-release forms, but do not have to be applied as often.
What fertilizer should I use?
Most turf experts recommend that a lawn fertilizer should have at least
one-half of its nitrogen in one of the slow-release forms mentioned above.
In most cases, both cool season and warm season grasses will do well when
a 3-1-2 or 4-1-2 ratio of N-P-K is used on an established lawn. Some analysis
numbers that meet these ratios are:
12-4-8
15-5-10
16-4-8
21-7-14
20-5-10
How much fertilizer should I use?
Fertilizer application rates should be as low as possible and still produce
a high quality lawn. Over-fertilization weakens your lawn and causes excess
leaf growth. As a general rule, if the amount of Nitrogen (N is the first
number in the analysis) is between 5 and 12, the application rate should
be 3.5kg per 100m2. If the N number is between 12 and 18, the application
rate should be 2.5kg per 100m2. Any N number over 19 should be applied
at a rate of 2kg per 100m2. Always follow the recommended rate stated
on the bag by the manufacturer.
When should I fertilize?
For warm season grasses, the fertilization program should start just after
spring green-up and stop as winter temperatures commence. Frequency of
fertilizer applications depends primarily on the amount and form of nitrogen
used. The slow-release type fertilizers can adequately feed the lawn from
6 to 10 weeks. If the lawn still looks good and is growing well after
6 to 8 weeks, wait longer for the next application.
Topdressing of lawns is carried out only to correct deficiencies in the
profile of the lawn. This process should not become an annual event. A
coarse washed river sand is the ideal material to use. All high quality
lawn areas will have been top dressed as the final stages of lawn establishment.
Topdressing should be carried out during the growing season, allowing
the grass to recover quickly and reducing any possible weed infestation.
Topdressing applications should be light - no more than 10mm and the
grass leaf should be still visible through the topdressing allowing the
plant to breathe and photosynthesise.
Should the lawn have been laid on a shallow soil base over clay/shale
etc., then it may be beneficial to include a percentage of finely screened
organic material with the sand. This will help to compensate for the lack
of correct soil preparation. (See our detailed section on soil preparation)
Also, if the lawn is thatched (thick and spongy) it may need to be renovated
before effective top dressing can take place.
The scarification process is the removal of thatch build-up in the turf
surface.
Thatch is the layer of vegetative material above the soil but below the
leaf. Nearly all lawns require this process at some stage of their life.
Different varieties have different rates of thatch build-up with the green
couch family (cynodon spp) having the greatest propensity to thatch and
blue couch (digitaria) the least.
A scarifying machine works by having vertical blades rotating at high
speed. These blades tease and thin out the dead material from the base
of the lawn
© Cleveland Turf Supplies 2002
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