Lawn & Turf Tips:
Weeds and Invasive Species
Common / Mouse-Ear Chickweed
Description
Common Chickweed-has smooth,
pointed leaves and likes moist, rich cultivated soil in shaky
areas and cool, damp weather. Mouse-Ear Chickweed -has elongated,
hairy leaves and thrives in wet, infertile soil and full sunlight.
Both flowers most of the year.
Chickweed grows from seeds that sprout in the fall
and live for less than a year.
Conditions
They grow primarily in damp,
shady areas under trees and shrubs and on the north side of
buildings. It invades home lawns when the begin to thin
out from insects, disease, mechanical damage, or shade.
It forms a dense mat that crowds out grass.
Cultural Control
Hoe, but remove plants after
they have been cut or new roots will sprout. Maintain
a well watered, properly fertilized and thick lawn to prevent
these weeds from taking a hold in your lawn. Do not
cut your lawn too short.
Chemical Control
During active growth in early
spring or late fall, treat the lawn with a weed killer containing
2,4-D and mecoprop. Repeated applications may be necessary.
Do not water for 2 days after a treatment.
Clover
Description
Low-growing invading weeds
with whitish flowers are found in lawns and gardens.
Clover spreads by seeds and above ground stems that sprout
at the nodes when they touch the soil.
Conditions
Thrives in cooler areas especially
if grass is cut too low.
Cultural Control
Hoe and mulch. Maintain
a well watered, properly fertilized and thick lawn to prevent
th ese weeds from taking hold in your grass. Do not
cut the grass too short.
Chemical Control
Use Chickweed, Clover &
Thistle Killer on the lawn. Repeat treatments are necessary.
In areas where you do not
want any growth at all, use RoundUp.
Comments
Clover seeds can live in the
soil for 20 years. Weeds should be actively growing
when using a herbicide. It is best to kill weeds before
seeds form.
Dandelion
Description
Reproduces from seeds and
shoots that grow from the fleshy taproot. The taproot
grows 2-3 feet deep in the soil, surviving even the severest
of winters. In the early spring, new sprouts emerge
from the taproot.
Conditions
Dandelions grow in any soil
and are most numerous in full sunlight. Dandelions prefer
wet soil and are often a sign of over watering.
Cultural Control
Hand- digging is impractical
since pieces of root that are broken off and left in the soil
will sprout into new plants.
Chemical Control
Treat an entire lawn with
a weed killer containing prop ionic acid; for spot treatment,
apply an gerbicide containing 2,4-D and mecoprop. For best
results make 2 applications, one in the early summer and another
in the early summer and another in the early fall. Do
not water or mow for 2 days after treatments.
Horsetail
Description
Perennial weeds, resembling little Christmas
trees, spread by means of spores and creeping roots.
These plants are native to Canada.
Conditions
Poorly drained, sandy or gravelly soil.
Cultural Control
Hoe and dig out the horsetail and take
all of the roots. Maintain a well watered, properly
fertilized and thick lawn to prevent these weeds from taking
a hold in your grass. Do not cut the grass too short.
Chemical Control
- Use Creeping Butercup Killer on the lawn. Repeat
as required when new spores germinate.
- Use Casoron in landscaped areas under plants that are
listed in the label directions.
- In driveways, patios, and other areas where you don't
want any growth at all, use RoundUp.
Oxalis-Wood Shamrock-Woodsorrel
Description
Perennial weeds with small
yellow flowers, clover like leaves and exploding deedpods
are found in lawns and gardens.
Conditions
Oxalis invades thin lawns
and thrives in dry, open places.
Cultural Control
Hoe and hand-pull before flowers
appear. Eliminate new shoots as soon as they appear
.
Maintain a well watered, properly
fertilized and thick lawn to prevent these weeds from taking
a hold in your lawn. Do not cut lawn too short.
Chemical Control
Use a lawn weed killer on
lawn. Where you do not want any growth, use RoundUp.
Comments
Weeds should be actively growing
when using a herbicide. It is best to kill weeds before
seeds form.
Purslane
Description
Purslane is a succulent that thrives in
hot, dry weather; it is seldom found in the spring when the
lawn is being treated for other weeds. It grows vigorously,
forming a thick mat. The small yellow flowers open only
in full sun June-October.
Conditions
Purslane primarily invades bare spots in
lawns or thin lawns that have not been watered properly.
Purslane stores water in its thick fleshy stems and leaves;
therefore, it survives longer tha n grass during dry weather.
Cultural Control
Hoe or hand pull and remove plant debris.
Use mulch in landscaped areas. Maintain a well watered,
properly fertilized and thick lawn to prevent these weeds
from taking a hold in your lawn. Do not cut lawn too
short.
Chemical Control
Treat in early spring, during flowering;
whenever weed is actively growing with 2,4-D and cecoprop..
Pre-emergence in Sept.-Oct. Wait 3-4 weeks after a treatment
before seeding bare areas.
Comments
Hard to control.
Spurge
Description
Numerous long, creeping stems tinged with
purple which ooze milky fluid when broken. Euphorbia
or Spurges form a low-growing, dense mat.
Conditions
Invades thin, undernourished turf under
periodic drought stress ; also in cultivated soil.
Cultural Control
Keep the lawn well watered
to discourage spurge from invading dry areas.
Chemical Control
Use a pre-emerge in late spring; post-emerge
while actively growing. Use mecoprop or dicamba.
Comments
Hard to control.
Crabgrass
Description
Sprouts from seeds in early
spring, growing rapidly and producing seeds all summer until
the first killing frost in the fall. The seeds lie dormant
over the winter and sprout in the spring. When a lawn
begins to thin out from insects, disease, or poor maintenance,
crabgrass is one of the first weeds to invade the area.
Mechanical Control
Hoe and dig out crab grass
and leave roots exposed so they dry out. Maintain a
well watered, properly fertilized and thick lawn to prevent
these weeds from taking a hold in your grass. Do not
cut the grass too short as this will diip the soil cool preventing
seeds from germinating.
Chemical Control
Kill actively growing crabgrass
with an gerbicide containing fluazifopbutyl, glyph sate, or
methanearsonate. Older plants are harder to kill; repeat
the treatment 2 or more times at 4-7 day intervals, if necessary.
To kill seeds as they germinate, apply a weed killer containing
DCPA in the early spring, 2 weeks before the last expected
froswt or about the time the Forsythia bloom.
Barnyard
Grass
Description
Usually found in poorly managed
lawns of low fertility. It reproduces from seeds and
develops into a plant with a shallow root system. Usually
upright but forms ground-hugging mats with mowing.
Cultural Control
Chemical Control
Kill mats of actively growing barnyard
grass with a chemical containing methanearsonate or fluazifopbutyl.
Repeat the treatment 2 or more times, at intervals of 7-10
days, until the plants die. The chemical may discolor
the turf for 2-3 weeks. To kill barnyard grass seedlings
as the sprout, apply a weed killer containing DCPA in the
early spring, 2 weeks before the last expected frost.
Goosegrass
Description
Resembles crabgrass but is
darker green and has silver center. Goosegrass stems
are smooth and flat. They form a rosette resembling
wheel spokes. Leaf blades ar 2" - 10" high and 1/5"
wide. It germinates when soil temps are 60°-65° F, seversl
weeks after crabgrass. It multiplies from seeds and
expands by spreading. It has an extensive root system.
It does not root at stem joints. Seeds a re produced
on stalks 2-6" high. Stalks appear from July-Oct.
Mature plants die with first frost. Seeds are dormant
over winter. It prefers compacted soils with poor drainage
and light, frequent watering.
Cultural Control
Aerate turf, provide good
drainage, water turf for longer periods and .less often.
Chemical Control
Use a treatment containing
calcium acid methanearsonate or a glyph sate compound.
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