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* each application consists of 0.5 kg of nitrogen per 100
m2 Irrigation Equipment Dormant Lawns
ThatchThatch is a layer of organic matter made up of decaying grass leaves, stems and roots that build up in between the lawn and soil surface. It is a common problem on Kentucky bluegrass lawns, that have been es-tablished for several years and over-watered and over-fertilized.Identification Why Is Thatch a Problem? Minimizing Thatch
Remove excess thatch by vertical mowing or core aerating. Core aerate using a hollow steel tine core aera-tor, which removes cores of soil. This physically breaks up the thatch, brings up beneficial soil micro-organisms that help break down the thatch and alleviates compaction. Timing
Overseeding and Timing
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Table 3. Seasonal lawn care calendar. |
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Early Spring (May) |
Late Spring (June) |
Summer(July) |
Late Summer(August) |
Fall (September) |
Late Fall (October) |
Fertilization (N-K-P) P and K to be established by soil tests |
|
Application |
Application only if lawn irrigated regularly or a wet season |
Application |
|
Application (late October) |
Mowing |
Mow as high as possible. Do not remove more than one-third of the leaf blade with each mowing. |
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Irrigation |
To keep turf from going dormant, irrigate at least one a week with 2.5 cm of water if there is insufficient rainfall. Irrigation iwth help with grub feeding. |
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Overseeding |
|
Application, if turf has been damaged by dieases or insects |
|
Application, if turf has been damaged by dieases or insects |
|
|
Aeration |
|
Application |
|
Application |
|
|
European Chafer and Japanese Beetle |
Check for grub damage. |
Overseed or sod damaged areas. |
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Check for small grubs. Apply beneficial nematodes for marginal control is large number of grubs are found. |
|
Check for grub damage. |
Hairy Chich Bug |
|
|
Check for chinch bugs. |
Overseed or sod damaged areas. |
|
|
Sod Webworm |
|
|
|
|
Check for sob webworm. Overseed or sod damaged areas. |
|
European Crane Fly |
Check for leatherjackets. |
Overseed or sod damaged areas. |
|
|
|
|
Diseases (turf dieases are treated with cultural practices) |
Assess snow damage, rake to encourage turf to dry up and fertilize lightly to encourage recovery. |
Monitor
for leaf spot, especially in excessibely wet springs
followed by hot, humid conditions.
Raise mowing height and fertilize lightly to encourage recovery. Avoid heavy application of nitrogen in early spring to minimize leaf spot and melting out. |
Monitor for necrotic ring spot. If it is a problem, aerate and overseed with perennial ryegrass in the late summer/early fall. |
Continue monitoring for necrotic ring spot. Follow cultural practices in previous column. |
Monitor for dollar spot. Fertilize if dollar spot becomes a porblem. Monitor for rust. I f rust is a problem, fertilize turf. Avoid fertilizing from mid-Sept. to mid-Oct. |
|
Hairy Chinch Bug
Hairy chinch bug damage starts to become noticeable from
mid-July to mid-August. This insect causes dam-age by
sucking plant juice from the grass stems with its piercing
and sucking mouth parts. The first signs of damage are
small, fist-sized sunken areas in the lawn. As the insects
continue to feed, these ar-eas can grow very rapidly into
large dead areas. Damaged areas are often taken over by
weeds. Adults are very small (4 mm long), and their wings
form an X on their backs. One method of detecting chinch
bugs is to cut the ends of a metal can to make a cylinder,
force it into the ground, then fill the cylinder with water.
Chinch bugs will float to the sur-face if they are present
in the lawn. An alternative method is to cut a square piece
of turf roughly 6-10 cm2. Place it in a bucket and wait to
see if any chinch bugs float to the surface. For more
informa-tion, see the OMAFRA Factsheet, Hairy Chinch Bugs in
Lawns, Order No. 08-019.
Grubs
Several species of grubs can cause damage by feeding on
grass roots in home lawns. The most common grubs are:
If animals such as skunks begin digging up the lawn or if
small irregular patches of grass turn brown, it may indicate
grubs present in the lawn. Check for grubs in late summer or
early fall before damage is noticed. Lift a section of sod
and soil, 10 cm square, with a spade, and look for white,
C-shaped grubs in the soil. Keeping the lawn well watered
helps minimize grub damage. Beneficial nematodes may be
applied for marginal grub control in the late summer. Follow
the instructions carefully. For more information on grubs,
see the OMAFRA Factsheet, Grubs in Lawns, Order No. 08-023w.
Sod Webworms
Sod webworms are caterpillars that feed in the thatch on
home lawns. The adults are small, tan moths that fly around
lawns at night. The caterpillars grow to 2 cm and are tan in
colour with dark spots on their backs. They feed in the
thatch, causing damage that is similar to grub damage, where
areas of turf can be lifted like a carpet. They also leave
behind soft green fecal pellets in the areas they are
feeding. The damage occurs in September.
Bluegrass Billbug
Bluegrass billbugs are in the weevil family. The adults are
black and 5 mm long. Larvae are small, white and legless
with a brown head. Damage begins with small groups of plants
turning yellow and dying. This occurs in mid-July to
mid-August. Damage is usually spotty and rarely affects a
whole lawn. Billbugs leave behind a sawdust-like excrement
in areas they have been feeding. This is helpful in
diagnosing the damage.
European Crane Fly
The European crane fly is a relatively new pest to lawns in
Ontario. The adult crane fly resembles a large mosquito. The
larvae are known as leatherjackets. They are light, greyish brown
with black specks. There is no visible head region. They
range in size from 0.5-3.0 cm in length. Leatherjackets feed
primarily on grass shoots during the evening and on grass
roots during the day. Damage begins to show early-to-mid-May
and peaks by mid-June. Heavy infestations of leatherjackets
can chew the grass down to the bare soil.
Turfgrass Scale
Turfgrass scale is a typical scale insect that resembles an
egg cut in half lengthwise. It is brown with a yellow stripe
in the middle. The immature stage, called a crawler, is the
size of the head of a pin. Typical damage is small patches
of dead grass that do not green up in the spring. They are
found mainly on sodded lawns and in general, do not cause
much damage. During early July, crawlers can be found on
shoes when you walk through the lawn.
Table 4. Summary of lawn-damaging insects.
Insect |
Description |
Damage |
Detection/Control |
Figure 1. Hairy Chinch Bug
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Figure 2. Grubs
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Figure 3. Bluegrass Billbug
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Figure 4. Sod Webworm
|
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Figure 5. European Crane Fly (leatherjackets)
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Figure 6. Turfgrass Scale
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Table 5. Summary of common lawn diseases.
Name |
Description |
Conditions favouring disease |
Damage and Control |
Fairy Ring
|
|
|
|
Leaf Spot
|
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|
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Mushrooms
|
|
|
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Figure 10. Necrotic Ring Sot
|
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|
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Figure 11. Powdery Mildew
|
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Figure 12. Rust
|
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Figure 13. Snow Moulds
|
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|
Endophytes
One way to combat the damage caused by leaf-feeding insects
is to plant grasses that contain endophytes. Endophytes are
fungi that grow inside the grass plant and make it taste
bad. Lawn insects repelled by endophytes are hairy chinch
bugs, bluegrass billbugs and sod webworms. Lawn species that
may contain endophytes are perennial ryegrass, fine fescues
and tall fescue. Consult your local garden centre or seed
supplier about the endophytic grasses they sell.
If a lawn becomes damaged or thins as a result of insect
feeding, it can be repaired by overseeding or sodding. See
the sections on overseeding and sodding earlier in this
Factsheet for more information.
Moss
Mosses are primitive forms of green plants that form dense,
low-growing clumps in a lawn. Moss plants have a tremendous
capacity to spread. They produce large numbers of spores,
each of which can give rise to a new moss plant. They can
also be propagated vegetatively by mowing. Mosses are poor
competitors with a healthy lawn and are only a problem when
the lawn is weakened by poor growing conditions. The
following conditions weaken a lawn and promote moss
invasion:
Cultural methods can be effective in controlling moss:
Disease problems in home lawns are minimal. Excessive
fertility can cause succulent growth that is more
susceptible to diseases. When establishing or renovating a
lawn area, select varieties that are resistant to various
diseases. Improper irrigation also contributes to lawn
diseases. Make sure to water in the early morning to
minimize the length of time that the lawn stays wet. A
summary of common turfgrass diseases on home lawns is shown
in Table 5.
If a lawn becomes damaged or thins as a result of lawn
diseases, it can be repaired by overseeding or sodding. See
the sections on overseeding and sodding earlier in this
Factsheet for more information.
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problems cannot be dealt with at the level of thinking that created
them." Albert Einstein |
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