Lawn Care/Basics for Homeowners-Lawn Care/Weed Identification and Control/Classification/Broadleaf Grasses
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| Photographer: Michael Clayton University of Wisconsin-Madison |
Also known as milfoil, thousandleaf, or woundwort, it is a perennial member of the Aster family (Compositae) that reproduces by seeds or short underground rootstocks. Upright common yarrow stems emerge from taproots to form a dense mat under close mowing. The stems are usually not branched; are smooth to densely covered with long, soft or woolly grayish-green hairs and are 4 to 24 inches tall. The tops of the stems may branch. The alternate, finely pinnately dissected and fern-like leaves are soft and covered with hair. The basal leaves longer than those growing on stem; stem leaves are 3 to 8 inches long. The flowers develop in falt-topped clusters at the top of branches. There are white or pink ray flowers and yellow disk flowers. Flowering occurs in June to October. Common yarrow often occurs in poor, gravely, droughty, and infertile soils and does not compete well with turf on rich soils. It is wear and drought tolerant. To control without chemicals, improve conditions for turf growth and mechanically remove in spring and prior to blooming. Apply post emergence broadleaf herbicides during periods of active growth from late spring through early autumn. This is a tough and durable, offensively aromatic weed. It has a bitter taste.
It is a cool season perennial member of the Lily family (Liliaceae) that reproduces
by seeds, aerial bulblets, and underground bulblets. Most reproduction in northern
states is asexual. Beginning growth early in the spring, wild garlic develops
from a bulb into an upright, grass-like plant with an onion or garlic odor. Stems
can grow to more than 3 feet. The leaves of wild garlic are 2-ranked, slender,
hollow, nearly round; and attached halfway down on waxy stem. The inflorescence
is an umbel, 1 to 2 inch diameter. The flowers are small, greenish-white, and
found on stems above the aerial bulblets. Flowering occurs during May and June.
Wild garlic is commonly found in poorly-drained, fine-textured, fertile soils
and thin turf areas. To control without chemicals, maintain turf density and health
through proper culture. Mow frequently and mechanically remove all, portions of
plants. Apply post emergence broadleaf
herbicides during early to mid spring when weeds are actively growing.
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| Photographer: Kenneth J. Sytsma University of Wisconsin-Madison |
It is a annual or winter annual member of the Mustard family (Cruciferae) that
reproduces by seeds. Shepherd's purse emerges from a thin, branched taproot
to form a rosette of leaves and thin, erect, usually branched stems to 24 inches
tall. The stems are usually covered with grayish hairs. Forming a rosette, the
basal leaves are simple, 2 to 5 inches long, and variably lobed, serrated, or
divided. Leaves on the stems are alternate, 1 to 4 inches long, and are usually
toothed or lobed. The base on these leaves are ear-like and clasp or rap around
the stem. The basal rosettes may be confused with dandelions in autumn; leaves
of Shepherd's purse are normally more narrow. Flowers on Shepherd's purse are
small and white with 4 petals set shape of cross. They are 1/12 to 1/6" wide
and occur in elongated clusters at ends of branches on slender stems. Flowering
period is from March to frost, and the fruit is a heart-shaped or triangular
capsule. Shepherd's purse occurs in thin turf and new seedings; it tolerates
saline soils. To control without chemicals, maintain turf density and health
through proper culture and use adequate seed to provide seedling density. Hand
pull or mechanically remove before flowering. Apply post
emergence broadleaf herbicides during periods of active growth in mid spring
and again during autumn.
It is a perennial member of the Pink family (Caryophyllaceae) that reproduces
by seeds and occasionally by creeping stems that may root where they touch the
soil. Mouse-ear chickweed have shallow, fibrous roots. The mat-forming plants
grow up to 20 inches tall and have weak, hairy, spreading stems. Mouse-ear chickweed
leaves are opposite, dark green, very hairy, and less than 1 inch long and up
to 1/2 inch wide. They are without petioles and oval to elliptically shaped. The
small, white flowers have five white petals that are notched at the tips. Hairy,
leafy sepals are borne beneath the flowers which occur April through July. Mouse-ear
chickweed grows in cool, moist soils, and shaded sites. Maintain dense, healthy
turf using good management. Hand-pull removing entire plants. Apply post
emergence broadleaf herbicides during periods of active growth from late
spring through early summer and again from early autumn through early winter;
apply preemergence products in mid
to late summer.
They are members of the Aster family (Asteraceae). Bull thistle is a biennial
that reproduces by seed, and Canada thistle is a perennial that reproduces by
seed and rhizomes. Bull thistle forms large, coarse plants with spiny leaves,
large taproots, and stems that are heavy and branched at top and hairy when mature.
Canada thistle also forms large, coarse plants with spiny leaves. The large, rhizomatous
underground system form stems that are grooved and branched at top, hairy in youth,
smooth when mature. Bull thistle leaves are deeply-lobed, spiny above and below,
and pubescent beneath. The leaf base joins stem resulting in winged appearance.
Leaves of Canada thistle are alternate, long, narrow ovals, with crinkled edges,
spiny margins and pubescent undersides. Inflorescences of Bull thistle are reddish-purple,
1-2" in diameter, and borne June through October. there are large spiny bracts
that surround the heads. Canada thistle flowers are borne July through October
and form lavender heads, up to 1" in diameter, without spiny bracts. Male
and female flowers are normally on separate stems or plants. Both Bull and Canada
thistles occur on poor, open turf throughout the growing season and are often
more common during cooler seasons. To control both thistles without chemicals,
maintain turf density and health through proper culture. Apply post
emergence herbicides in mid spring to early summer, mid to late autumn during
periods of active growth.
It is a warm season member of the Spurge family (Euphorbiaceae) that reproduces
by seeds. Germination occurs when soil temperatures warm to 60 to 65 oF and can
continue as soil temperatures climb to more than 90 oF. Prostrate spurge develops
a central taproot from which prostrate stems that form a flat, extensively branched
mat up to 2 feet in diameter. The stems exude milky sap when broken. Leaves of
prostrate spurge are opposite, small, oval, and up to 3/5 inch long. They are
sometimes purple-spotted and/or hairy. The petioles are short. Prostrate spurge
flowers are very small and inconspicuous. They are cup-shaped and develop in terminal
clusters or leaf axils. They occur June to October. This weed is found in poor,
drought-stressed, open turf. It germinates and grow well during hot, dry weather
on thin soils and is often found on closely mowed sites. To control prostrate
spurge without chemicals, maintain turf density and health through proper culture;
water deeply, fertilize in autumn, and avoid close mowing. Mechanically remove
or hand pull. Apply preemergence herbicides before germination in spring; apply
postemergence herbicides in late spring through mid summer when plants are young
and actively growing.
Also known as creeping Charlie, it is a perennial member of the Mint family (Lamiaceae)
that reproduces by seeds and root pieces. It may form patches in turf as it creeps
on square stems that can grow up to 2 1/2 feet long, sometimes rooting at the
nodes. Occasionally the stems grow in an ascending fashion. Leaves of ground ivy
are opposite, round to kidney shaped, and 1/2 to 1 1/2 inches in diameter. They
may be smooth or hairy, medium to dark green, have long petioles and a rounded,
toothed margin. They produce a minty odor when crushed. The flowers are small,
lavender to blue-purple, funnel shaped and clustered in leaf axils. Ground ivy
flowers occur April to June. This weed normally occurs in shaded sites with poorly
drained, fertile soils. It can spread into sunny areas. To control ground ivy
without chemicals, maintain turf density and health through proper culture and
alter the turf environment by reducing shade and soil moisture. Mechanical removal
is difficult and rarely effective. Apply post
emergence herbicides in mid spring to early summer and/or mid to late autumn
when is actively growing. Ground ivy is difficult to control, and has been used
as ground cover in shady areas.
It is a member of the Mint family, is a cool season annual or biennial that reproduces
by seed and rooting stems. Henbit stems droop and then turn upright to grow to
16 inches tall. They may root where they touch the ground. They are square, green
to purplish, and smooth or hairy. The roots are fibrous. The 1/2 to 1 inch long
leaves of henbit are opposite, dark green and hairy above and lighter below. The
lower leaves have petioles and the upper leaves are borne directly on the stem.
the leaves are triangular to circular and have palmate venation. The leaf edges
have rounded teeth and are crinkled at the edges. Henbit flowers are tubular,
pink to red to purple, and borne in whorls in the upper leaf axils. They appear
to have two lips and are up to 3/4 inch long. henbit normally flowers April to
June and occasionally in September. Henbit is often found growing in moist, fertile
soils. To control henbit without herbicides, maintain density and health in established
turf and avoid thin seedings in the autumn. Small populations can be hoed or hand
pulled. Apply post emergence herbicides
from mid through late spring and again from mid to late autumn. Preemergence herbicides
should be applied in late summer prior to germination. Because henbit grows in
cool conditions, it can be a problem in warm season turf.
It is also known as common mallow, cheeses, dwarf mallow, running mallow, malice,
round dock, and button weed. It is an annual or biennial member of the Mallow
family (Malvaceae) that reproduces by seed. Emerging from a short, straight taproot,
roundleaved mallow develops stems up to 12 inches long. The hairy stems are horizontal
or upright and may be branching at base. The stems do not root as they touch the
ground. The simple, alternate leaves of roundleaved mallow are round to heart-shaped
usually with 5 to 9 shallow lobes or rounded teeth. They are up to 2 1/2 inch
across and hairy on both surfaces. The petioles are also hairy and up to 4 inches
long. Flowers of roundleaved mallow are solitary or borne in clusters of two to
four in leaf axils. The flowers have five white petals and are often tinged pale
lilac and grow up to 1/2 inch long. The fruit is a flattened disk with 10 to 20
small, hairy segments with one seed per segment. Flowering occurs May through
September. Roundleaved mallow occurs in wet, humid regions in stressed or thinned
turf. To control roundleaved mallow without herbicied, maintain density and health
in established turf. Small populations can be hoed or hand pulled. Apply post
emergence broadleaf herbicides from mid spring through early summer during
periods of active growth.
It is an annual, biennial or perennial member of the Legume family (Fabaceae)
that reproduces by seeds. Black medic is shallow rooted with multi-branched slender,
prostrate, slightly hairy stems spreading 12 to 24 inches. The alternately arranged,
dark green leaves are compound with three, oval leaflets. The center leaflet is
stalked and the side leaflets occur close to the stem. Leaves are sparsely hairy
and the leaflets 1/5 to 3/5 inch long. The 1/8 to 1/6 inch long bright yellow
flowers are clustered on short stems that emerge from the leaf axils. Each cluster
is approximately 1/2 inch long, round, and comprised of up to 50 individual flowers.
Flowering occurs April to October. Black medic occurs in a variety of turf settings
and can be hand pulled. Apply post emergence
broadleaf herbicides during periods of active growth from late spring through
early summer and again from early through mid autumn.
It is a perennial (may act as a warm-season annual) member of the Woodsorrel family
(Oxalidaceae) that reproduces by seeds and occasionally stem pieces. Yellow woodsorrel
emerge from a taproot and forms small, erect, bushy plants up to 20 inches tall.
The stems are slender, gray-green, hairy, slightly ascending, and branched at
the base. They will occasionally root at nodes. The leaves of yellow woodsorrel
are alternate with three heart-shaped leaflets. They are pale green, up to 4/5
inch across with long petioles. Yellow woodsorrel flowers are yellow with five
petals. they are up to 1/2 inch across and borne at end of stems in clusters of
one to four. They are borne during May to September. Yellow woodsorrel occurs
in moist, open, fertile sites from mid spring to mid autumn. It seems to tolerate
dry conditions when established. To control yellow woodsorrel without chemicals
maintain turf density and health through proper culture. Mechanically remove or
hand pull. Apply pre-emergence herbicides prior to germination in spring; use
post emergence herbicides in mid
spring to early summer and/or mid to late autumn during active growth. This weed
is difficult to control. |
| Photographer: Elizabeth Parnis Andrews University |
It is also called broadleaf plantain (P. major). They are cool season
perennial members of the plantain family (Plantaginaceae) that reproduces by
seeds. These plantains form a spreading or upright basal rosette of broadly-oval
leaves with fibrous roots. The leaves are broad-oval, pubescent or smooth, and
dark green. The petioles are often with purplish. The leaves are up to 10 inches
long, the margins entire or wavy, and the veins are prominent and parallel.
Plantain flowers are numerous, inconspicuous, and small. They are borne along
the ends of flowering stalk and appear like fingers or rat-tails. They grow
8 to 20 inches tall during May to September. Blackseed or broadleaf plantains
occur in damp, infertile or fertile lawns throughout growing season. They will
tolerate some shade. To control these weeds without chemicals, maintain turf
density and health through proper culture. These weeds can be hand-pulled or
mechanically removed. Apply post emergence
herbicides in mid spring to early summer and/or mid to late autumn when
weeds are growing actively. Preemergence herbicides can be applied prior to
seed germination.
It is a cool season perennial member of the plantain family (Plantaginaceae) that
reproduces by seeds and roots. Buckhorn plantain forms a spreading or upright
basal rosette of narrowly oval leaves that grow above a long, sturdy taproot with
lateral branches. Leaves of buckhorn plantains are sometimes twisted and curled,
narrowly-oval, dark green, and up to 1 1/2 inches wide and 8 inch long. The tips
are sharp and the veins are prominent. Buckhorn plantain forms many small flowers
that are tightly clustered at the ends of long stems. The inflorescences resemble
a bullet. The flower stalks are 6 to 30 inches tall, and the flowers occur during
May to October. Buckhorn plantains occur commonly in low-quality turfs of low
to moderate soil fertility throughout growing season. To control this weed without
chemicals, maintain turf density and health through proper culture, especially
fertilization. Mechanically pull removing as much of the taproot as possible.
Apply post emergence herbicides in
mid spring to early summer and/or mid to late autumn when weeds are growing actively.
Preemergence herbicides can be applied prior to seed germination. |
| Photographer: Emmet J. Judziewicz University of Wisconsin-Stevens Point and Madison |
It is also known as knotgrass. It is a warm season member of the Polygonaceae
(Buckwheat Family) that reproduces by seeds. During early spring, knotweed resembles
a grass with long, dark green leaves when germinating. Later, it forms a flat
mat up to 2 feet in diameter. It has slender, wiry stems; and emerges from a
taproot. There are papery sheaths at each node that give stems a knotted or
swollen appearance. The leaves are alternate, small, narrowly oval, dull bluish-green,
and up to 1 1/4 inches long and 1/3 inch wide. Its flowers are small, borne
in clusters in leaf axils. The buds are purplish opening to white to yellow
flowers during June through October. Knotweed is found in compacted, infertile
soils or thin turf in sun; often adjacent to heavily trafficked walks or drives
or over-used play or athletic sites. It germinates in early spring and continues
growth through autumn. Control knotweed by reducing soil compaction; by maintaining
turf density and health through proper culture; and by mechanically pulling
it. Apply preemergence herbicides prior to germination in spring; apply post
emergence herbicides in mid spring through late summer when plants are
young and actively growing.
It is also known as wild portulaca. It is a warm season annual member of the Purslane
family (Portulacaceae) that reproduces by seeds or rooting stem pieces. Common
purslane emerges from a heavy taproot, to develop succulent, smooth, fleshy stems
that are usually purple-red and may root at lower nodes. these many branched stems
reach up to 24 inches long and grow in a prostrate fashion to form mats. Common
purslane leaves are alternate to sub opposite, oval shaped with the widest point
beyond the leaf's middle. Growing up to 1 1/4 inch long, the thick, fleshy leaves
are often clustered near the ends of branches. They are smooth and without leaf
stalks. The yellow flowers of common purslane are borne individually in the leaf
axils or clustered at end of branches. There are five petals. The fruit is a globular
capsule. Flowering occurs in July through September. Common purslane occurs in
rich fertile soils, and can be troublesome in late summer seedings. Once established,
common purslane is drought tolerant. To control common purslane without herbicides,
maintain turf density and health through proper cultural practices. Mechanically
remove common purslane, but destroy the stems as they may root in open soil. Apply
post emergence herbicides in mid
summer through early autumn during periods of active growth; apply preemergence
products in mid to late spring. |
| Photographer: Merel R. Black University of Wisconsin-Madison |
It is a perennial member of the Buckwheat family (Polygonaceae) that reproduces
by seeds and rhizomes. Red sorrel creeps using an extensive, shallow system
of roots and rhizomes and sends up new plants at branches. Slender, erect simple
of branching stems emerge from the rosette of leaves and can reach 6 to 18 inches
in height with flowers borne at the apex. The simple leaves of sheep sorrel
are fleshy, approximately 1 to 3 inches long, and arrow-shaped having two basal
lobes. They mostly emerge from a rosette in the early period of growth and alternate
along the stem later. The leaves have an acid taste. The flowers are yellow
to red borne clustered at the ends of stems. Flowering occurs June to August
and male and female flowers develop on different plants. Sheep sorrel occurs
in acidic soils of low fertility, often where there is a lack of competition.
Hand pull plants attempting to remove entire root mass and all rhizomes. Apply
post emergence broadleaf herbicides
during periods of active growth from mid spring through early summer and again
during autumn.
It is a perennial member of the Buckwheat family (Polygonaceae) that reproduces
by seeds and occasionally root pieces. Curled dock develops a dense rosette of
6 to 12 inch-long leaves that emerge from a large, fleshy, somewhat branched yellow-orange
taproot on a short crown. At flowering, the inflorescence develops at the top
of a stem that can reach 4 1/2 feet tall. The dark green leaves are simple with
a heart-shaped base. The leaf edges are wavy or curly. Leaves on the stem are
alternate and have short petioles. There is a papery sheath that surrounds stem
at the nodes. The flowers appear in branched clusters at the end of upright stems
that are 6 to 24 inches long. Initially yellow-green, the small flowers with slender
stems occur June to September and dry to develop rust-brown, three-seeded fruit.
Curled dock is commonly found in poor soils and waste areas where turf receives
inadequate maintenance. Maintain a dense healthy turf and pull when plants first
emerge. After developing the large taproot, hand-pulling is rarely effective.
Apply post emergence herbicides during
periods of active growth from mid spring through early summer and again in autumn.
It is an annual or cool-season annual member of the Pink family (Caryophyllaceae)
that reproduces by seeds and creeping stems. This weed may persist through summer
in sites that are protected from heat and drought. Common chickweed is low-growing
and can form large, dense patches. The hairy, creeping stems root at nodes and
produce shallow, fibrous roots. Leaves of common chickweed are bright green, opposite,
simple, broadly oval, and usually less than 1 inch long. The margins are entire.
The small, white flowers of common chickweed are 1/2 inch in diameter, and star-shaped
with five petals. Flowering occurs during the spring. Common chickweed occurs
in cool, moist, shady, often compacted, fertile sites in spring and autumn. To
control common chickweed without chemicals, maintain turf density and health using
proper culture, allow turf to dry between waterings, or mechanically remove. Apply
post emergence herbicides in mid
spring to early summer and/or mid to late autumn during active growth; apply preemergence
herbicides prior to germination in late summer or early autumn.
It is a cool season perennial of the Aster family (Asteraceae) that reproduces
by seeds and root pieces. Dandelions emerge above a long, sturdy taproot to form
basal rosettes of narrow, deeply lobed leaves. These leaves are 2 to 10 inches
long and up to 2 1/2 inches wide. They have jagged lobes that point back towards
stem. Dandelion inflorescences are yellow, up to 2 inches in diameter, and appear
to be solitary. They are borne on hollow stems that can grow up to 20 inches long,
and held above the foliage. The inflorescences ripen to become round "puffballs"
of wind-dispersed seeds. Flowering period is from early spring to late fall. Dandelions
occur in most lawns throughout the growing season, especially thin turf areas.
To control dandelions without chemicals, maintain turf density and health using
proper culture; mow often to remove seed heads prior to seed maturation, and mechanically
pull removing as much root as possible. Apply post
emergence herbicides during periods of active growth in mid spring to early
summer and/or mid to late autumn; preemergence herbicides should be applied prior
to seed germination.
It is a cool season perennial member of the Legume family (Fabaceae) that reproduces
primarily by seeds and occasionally creeping stems. White clover creeps to form
patches in turf and emerges from a fibrous root system. It can root at nodes on
creeping stems. The compound leaves are comprised of three unstalked oval leaflets,
up to 4/5 inch long. They are dark green and often with faint, white, crescent-shaped
markings. White clover inflorescences occur in ball-shaped white to pink clusters
of pea-shaped flowers that are held slightly above the foliage. The inflorescences
are up to 1 1/4 inch in diameter, composed of 40 to 100 flowers, and appear May
to September. This weed occurs in most lawns and especially in moist, low-fertility
soils throughout growing season. To control without chemicals, maintain turf density
and health using proper culture. Do not fertilize heavily with phosphorus. Mechanically
remove or hand pull. Apply post emergence
herbicided in mid spring to early summer and/or mid to late autumn when weeds
are growing actively. White clover was formerly a common component of turf mixes
due to its ability to fix nitrogen. It is still currently available in mixes or
by itself and may be useful in low management turf areas. It has the ability to
persist at short mowing height and can attract bees to lawns.
They are members of the Viola family (Violaceae) and form a variable group with
many species of cool-season annual or perennial plants. All can reproduce by seeds
and the perennial types can also reproduce by creeping rhizomes. Common violets
are low-growing, up to 12" tall, and can form large, dense patches by spreading
rhizomes and fibrous root system. Common violet leaves are kidney-shaped to broadly
oval with heart-shaped bases. They are 2 to 4 inches wide, often cupped, with
margins that are often toothed. They emerge from the base of the plant on long,
slender, slightly hairy petioles. flowers of common violets are pansy-like, white
to blue to purple, and also yellow. The side petals are hairy near the base. Common
violet flowers appear early in spring. These weeds are very shade-tolerant and
occur in moist, shady, fertile sites. They are most obvious in spring and autumn
when conditions are cool. To control common violets without chemicals, maintain
turf density and health using proper culture, reduce shade, and allow soil to
dry to improve turf competitive advantage. Apply post
emergence herbicides in mid spring to early summer and/or mid to late autumn
during active growth. Common violets are difficult to control in turf settings.Lawn Care/Basics for Homeowners-Lawn Care/Weed Identification and Control/Classification
