What is a weed? a strong-smelling plant from whose dried leaves a number of euphoriant and hallucinogenic drugs are prepared
Introduction The definition of a weed is any plant that is growing where it is not wanted. Weeds in turf are undesirable for the following reasons: They compete with turfgrass plants for water, nutrients, space, and light. They are unsightly and disrupt use of lawns and other recreational turf areas (parks, golf courses, etc.) Weeds quickly invade thin turf.
Tall fescue Pokeweed Yellow nutsedge Large crabgrass
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Introduction Developing an Effective Weed Management Program Identify the desired turfgrass so you can correctly fertilize, water, and mow Identify the existing weeds so you can correctly choose the best herbicide Identify future weeds as they appear so you can correctly choose the best herbicide
% Crabgrass 80 70 60 Effect of Mowing Height on Crabgrass Incidence in Tall fescue a 79 74 a 50 40 30 20 b 31 10 0 1.0" 2.0" 3.0" 4.0" Mowing Height Data Collected: 09-13-07, LSD (P=0.05), Sandhills Research Station, Sodman 90/10 (mixture w/ bluegrass) c 0
4 Photos Aug 2007 3 2 1
% Crabgrass Effect of Mowing Height on Large Crabgrass Incidence in Common Bermudagrass 25 20 a 23 a 25 a 15 18 15 a 10 5 0 0.5" 1.0" 1.5" 2.0" Mowing Height Data Collected: 09-13-07, LSD (P=0.05), Lake Wheeler Field Labs
Jan 11, 2008 0.5 Jan 11, 2008 2
Grass Identification Grass Vegetative Key: Identifies grasses only (weeds and turf) using vegetative instead of reproductive characteristics (Why is this important?) Flower and reproductive structures are constantly being removed by mowing, so you may not regularly see these characteristics in turf Mowed grass often impossible to ID at a glance
Grass Vegetative Key Based primarily on 1. Leaf vernation 2. Ligule 3. Auricle 4. Collar 5. Sheath and also presence or absence of rhizomes or stolons
Grass Vegetative Key Leaf vernation is the arrangement of the leaves of the budleaf (youngest leaf) and surrounding sheath. Leaf vernations are either rolled or folded in the bud leaf. Crab-rolled; Goose-folded I. rye-rolled; P. rye-folded
Grass Vegetative Key Ligule is a protruding structure from the upper leaf surface where the blade and sheath join. Ligules can be membranous (shiny), hairy, membranous with hairs or absent.
Grass Vegetative Key Auricle is a pair of appendages protruding from the sides of the grass leaf at the junction of the blade and sheath. Auricles can be rudimentary (short and blunt), large and claw-like or absent.
Grass Vegetative Key Tall fescue has short or blunt auricles. Perennial ryegrass has blunt to claw-like auricles. Italian ryegrass has clasping, claw-like auricles The remaining common NC grasses have no auricles.
Grass Vegetative Key Collar is the region on the back side of a leaf where the leaf blade and sheath are joined. Collars can be divided by the leaf midrib or continuous, with shapes ranging from broad to narrow; can be hairy or smooth.
Grass Vegetative Key Sheath is the basal portion of the leaf between the crown and blade. Sheath margins can be split (V-shaped), split with overlapping margins or closed; can be hairy or smooth, flattened or rounded.
Why are weeds present in turgrass? Weeds are the result of improperly managed turfgrass.
What is Properly Managed Turfgrass? 1. Turf species that is adapted to its environment Should you choose cool or warm season turf? Raleigh is in a transition zone where both grow pretty well but problems can occur with each Example: Tall fescue doesn t like 85+ degrees and warm humid conditions (susceptible to diseases). Bermuda can suffer winter kill in harsh winters.
What is Properly Managed Turfgrass? Is the turf shade tolerant? (St. Augustine, tall fescue, fine fescue, perennial bluegrass, zoysiagrass can withstand some shade) Does the turf require full sunlight? (Bermudagrass)
What is Properly Managed Turfgrass? 2. Turf mowed at proper height & frequency 3.5 Inch Turf Mowing Height Tall fescue Tall fescue / fine fescue / per. bluegrass mixtures Grown in western and central NC
What is Properly Managed Turfgrass? 0.75 1 Inch Turf Mowing Height Bermudagrass Centipedegrass Zoysiagrass Grown in eastern and central NC
What is Properly Managed Turfgrass? 3. Turf that is fertilized at the proper time with the proper rate and technique
What is Properly Managed Turfgrass? Cool Season Turf Nitrogen Timings and Amounts For all cool season turf, start applications in September October and finish in February March. Do not apply nitrogen in the spring or summer because of disease concerns. 3 lbs of N per 1000 sq ft per year is sufficient.
What is Properly Managed Turfgrass? Warm Season Turf Nitrogen Timings and Amounts Timings and rates vary between species, but generally start in the spring and fertilize through summer. Do not apply nitrogen in the fall or winter. Total N rates range from 0.5 lb per 1000 sq ft per year for centipedegrass to 6 lbs for hybrid bermuda.
What is Properly Managed Turfgrass? 4. Turf site that is well drained, noncompacted and receives adequate rainfall or irrigation If turf areas stay wet continuously, weeds such as nutsedge and kyllinga species will invade because they are better adapted to wet environments.
Weed Control Procedures A successful weed management strategy should integrate all of these procedures and not rely heavily on one. Preventative Mechanical Biological Cultural Chemical
Weed Control Procedures Preventative Good sanitation Clean mowers, tillage implements and other turf equipment before moving to new sites to remove weed seeds and vegetative material.
Weed Control Procedures Mechanical Physical removal by hand or tillage; mowing Effective on many annual weeds when the growing point is removed or buried Ineffective on many perennial weeds that have underground storage organs unless done repeatedly
Weed Control Procedures Biological Biological weed control utilizes natural enemies such as insects, fungi, bacteria and nematodes. This method works very slowly and does not produce rapid kill like chemicals; usually not enticing or practical for the turf industry. People usually want problems fixed quickly.
Weed Control Procedures Cultural The best way to prevent weed problems in turf is to properly manage the turfgrass. Select an adapted grass species Mow at proper height and frequency Fertilize at proper time and rates Irrigate as needed in morning, not late evening Improve soil drainage by adding soil or soil mixes
Weed Control Procedures Chemical The quickest, practical way to prevent or control weed problems in turf is to apply herbicides. Herbicides are short-term solutions. Results can be seen quickly, and people are happy. Herbicides do not correct the problem as to why weeds were present in the first place. As long as the problems are not corrected, the need for herbicides will exist.
Introduction Developing an Effective Weed Management Program Proper cultural management practices will enhance turfgrass growth and reduce weed competition and encroachment, thus reducing the need to rely solely on herbicides for effective weed control.
Introduction Weeds are generally placed into one of three categories based on their growth characteristics. Grassy weeds Monocots (one cotyledon seed leaf that emerges from soil) Leaves arranged in two vertical rows Stems are hollow, not solid Sedges Leaves arranged in three vertical rows Stems are solid, not hollow Triangular stems Broadleaves Dicots (two cotyledons seed leaves that emerge from soil)
Introduction They are also categorized into one of three life cycles. Summer annuals Summer annuals germinate in the spring when soil temperatures reach about 55 o F, flower in the summer and die in the fall at the first frost. Winter annuals Winter annuals germinate in the fall, grow until spring and die during late spring or early summer. Perennials Perennial weeds are capable of living more than two years. Perennial turfgrasses can be considered weeds if not wanted!!!
Introduction Grassy Weeds S. Annuals W. Annuals Perennials Smooth crabgrass Annual bluegrass Dallisgrass Large crabgrass Italian ryegrass Bull paspalum Goosegrass Annual blueeyed Bahiagrass Barnyardgrass Yellow foxtail Green foxtail Sandbur Japanese stiltgrass Per. ryegrass Orchardgrass Nimblewill
Smooth and Large Crabgrass Can root at lower nodes which enhances survival Rolled leaf vernation, membranous ligule
Smooth and Large Crabgrass Most common summer annual grasses in NC Crabgrass quickly invades thin, open turfgrass stands.
Jun 7, 2010 Thorndale Country Club
Smooth and Large Crabgrass Apply a preemergence herbicide in February early March before germination (a single full labeled rate or two half-labeled rates applied at 8 week intervals depending on product). If no irrigation, use granules pre when possible. Control postemergence in late spring to early summer (before seedhead formation).
% Control Preemergent smooth crabgrass control averaged over 1997-2007 100 80 81 89 87 90 92 Dimension [4] 0.5 lb Surflan [3] 3 lb Ronstar [14] 2-3 lb 60 Pendulum [3] 2-3 lb 40 Barricade [3] 0.5-0.75 lb 20 0 Rates are lb ai/a, averaged across formulations, locations, years.
% Control Application Effects on Smooth Crabgrass 2002 2007: Wesleyan College 100 80 77 85 One Application 60 b a 40 20 Two Applications 0 September
Goosegrass Bicycle spoke silvery base appearance
Summer annual Weeds in Turf Goosegrass Germinates in spring when soil temperature reaches 60 F near the soil surface (2 weeks later than crabgrass) Competitive in compacted soils Does not root at the nodes like crabgrass Folded leaf vernation
Very troublesome in closely-mowed turf and compacted soils
Goosegrass Preemergence control at same timing and with same products as with crabgrass However, these products not as effective on goosegrass as they are with crabgrass Postemergence control as needed when young and actively growing before seedhead formation
Barnyardgrass, Yellow and Green Foxtail
Barnyardgrass, Yellow and Green Foxtail These summer annuals are seldom found in highly maintained turf. They are found mostly in utility turf areas such as roadsides. Control with preemergence crabgrass / goosegrass herbicides at same timings. Barnyardgrass no ligule Yellow foxtail 1/3 leaf towards base hairy Green foxtail leaves smooth, no hairs
Yellow foxtail Hairs at base of leaves
Sandbur
Sandbur Summer annual or short-lived perennial Preemergence crabgrass / goosegrass herbicides provide only fair control. Postemergence herbicides applied to seedling sandbur provide some level of control.
Japanese Stiltgrass Dec 13, 2006 Sep 23, 2004
Summer annual grass Weeds in Turf Japanese Stiltgrass Grows well in shaded, woody areas Easy to hand-weed due to weak root system Preemergence crabgrass / goosegrass herbicides provide effective control. Postemergence herbicides also provide effective control.
Annual Bluegrass Folded leaf vernation Boat-shaped leaf tips Prolific seed producer
Winter annual Weeds in Turf Annual Bluegrass Possibly the most troublesome weed in NC? Perennial biotypes exist, especially in greens Capable of surviving close mowing, frequent irrigation, aerification, fertilization, etc. Preemergence herbicides not effective on perennial biotypes
Annual Bluegrass True annuals can be controlled in late summer / early fall with preemergence crabgrass / goosegrass herbicides but may affect overseeding. In dormant bermudagrass, annual bluegrass can be controlled with postemergence selective and nonselective herbicides.
Monument 75WG 0.47 oz/acre May 4, 2004 (16 WAT)
Italian Ryegrass Shiny leaves appear wet; sawtooth seedhead Claw-like auricles; rolled leaf vernation
Winter annual Weeds in Turf Italian Ryegrass Common in turfgrass roadsides, overseedings Control with preemergence crabgrass / goosegrass herbicides in late summer. Can be controlled with postemergence herbicides in certain turfgrass stands. However, resistance can be a concern if using the same product yearly.
Annual Blueeyed Grass
Winter annual Weeds in Turf Annual Blueeyed Grass Resembles goosegrass in appearance when young Produces bluish-purple flowers in the spring Control postemergence in warm season turf with sulfonylurea herbicides and 2- or 3 way broadleaf herbicides (even though a grass)
Dallisgrass Resembles crabgrass but thicker seedhead Bull Paspalum Glossy leaves with hairs on leaf edges
Dallisgrass and Bull Paspalum Warm season perennials Extremely difficult to control in turfgrass stands Only effective herbicide for years has been MSMA (repeat applications) As of Sep 30, 2009 MSMA can only be applied to sod farms, golf courses and highway rights-of-way due to EPA restrictions Dec 31, 2012: MSMA only sold for cotton use
Dallisgrass Control???
Turfgrasses as perennial weedy grasses Bahiagrass Perennial Ryegrass
Turfgrasses are generally very difficult to control within another turf species. Control is possible through manual removal of the weed or spot treating with a nonselective herbicide. Selective removal with herbicides is possible in some situations.
Bahiagrass Found on roadsides and rightsof-way Y shaped seedheads
Bahiagrass Thick scaly rhizomes usually pinkish brown Good drought tolerance and very competitive
Bahiagrass can often be a problem in high maintenance turf and is generally difficult to control. Control can be achieved in bermudagrass but it takes at least two applications of a postemergence herbicide.
Perennial ryegrass Folded leaf vernation; blunt to claw-like auricles
Perennial Ryegrass Like Italian ryegrass, has sawtooth seedheads and shiny leaves appear wet. Overseeding bermudagrass with perennial ryegrass is a common practice for providing winter color. Unfortunately, the same perennial ryegrass that was planted for color during the winter quickly becomes a weed during the summer.
Perennial Ryegrass In the transition zone of NC it can persist well into the summer becoming clumpy and hard to control. Control during spring transition in late May with postemergence sulfonylurea herbicides is one solution.
May 15, 2008 (2 WAT)
Orchardgrass Bluish-green color, pointed membranous ligule Folded leaf vernation
Nimblewill
Warm season perennial Nimblewill Extremely difficult to control in turfgrass stands Looks like bermudagrass except nimblewill has a membranous (shiny) ligule whereas bermudagrass has a hairy ligule
Sedges and Kyllinga Species These species resemble grasses BUT have three-sided, solid triangular stems.
Sedges and Kyllinga Species Mostly perennials, and some annual types Perennials are hard to control and multiple applications are often needed. Common in warm, wet, poorly drained soil conditions but can spread to other turf areas Difficult to properly id when seedheads are mowed
Yellow Nutsedge Forms chestnut-colored tubers from rhizomes Yellowish-brown seedhead, needle-like leaf tips
Yellow Nutsedge Fairly cold-tolerant perennial sedge species Can invade thin tall fescue turf stands Control in spring using postemergence herbicides before tuber development, which begins in June or July Usually not found in highly managed bermuda due to consistent 0.5 mowing
Purple Nutsedge Perennial sedge sp. found in temperate and tropical regions, mostly in warm-season turf Reddish-purple seedhead, blunt leaf tips Purple Yellow
Purple Nutsedge Forms charcoal-colored tubers from rhizome chains; same control options as yellow nutsedge
Jun 30, 2009 (2 WAT))
Green and False Green Kyllinga Minty odor when crushed or mowed More mat-forming than purple / yellow nutsedge
Green and False Green Kyllinga Perennials with well-developed rhizomes; no tubers Survive close mowing and poorly-drained turf Green kyllinga commonly found in warmer climates (Coastal plain) and can seed throughout the summer; false green kyllinga commonly found in cooler climates (Piedmont and Mountains) and seeds all at once in late summer / early fall Control with postemergence nutsedge herbicides.
False green kyllinga May 23, 2007
Monument + NIS 0.56 oz/a + 0.25% May 23, 2007 (4 WAT)
Annual Sedge
Annual Sedge True annual, easier to control than perennials Some preemergence crabgrass / goosegrass herbicides provide partial control. Better control is achieved with postemergence herbicides.
Globe Sedge Weeds in Turf Cylindric Sedge
Perennial sedges Weeds in Turf Globe and Cylindric Sedge Globe: globe-shaped seedheads Cylindric: cylinder-shaped seedheads Can reproduce by seed; preventing seedhead formation will reduce the chance of spread Control with postemergence herbicides
Winter Annual Broadleaf Weeds Many winter annual weeds are controlled with combination products containing two, three or four broadleaf herbicides. Postemergence control is generally best achieved during late fall or early winter during seedling stage. Control can also be achieved the following spring from February-April when temperatures are conducive for chemical uptake.
Winter Annual Broadleaf Weeds Postemergence nonselective control with glyphosate is also an option in dormant nonoverseeded bermudagrass. Some winter annual broadleaf weeds such as common chickweed and henbit may be controlled with preemergence herbicides applied in the late summer / early fall before expected germination.
Hairy Bittercress
Hairy Bittercress Winter annual with erect stems easy to control Overwinters as a basal rosette Leaves deeply lobed Small flowers with 4 white petals Linear fruit capsule about 0.75 that pops open when mature
Buttercup Species Two common winter annuals that are easy to control are small flower buttercup and hairy buttercup Erect, hairless plant Small flower buttercup Lower leaves unlobed with long petioles (violet shape) Upper leaves deeply dissected Flower with 5 yellow petals that produces cluster of teardrop-shaped seeds with slightly curved beaks
Hairy buttercup Acts as winter annual or short-lived perennial Hairy plant with erect stems and lobed leaves Differs from bulbous in that no swelling at base of stem Flower with 5 yellow petals that produce cluster of teardrop-shaped seeds with minute spiny sides and hooked beaks
Common Chickweed White flower with 5 deeply notched petals
Common Chickweed Low spreading winter annual, weak root system Roots at the nodes but easy to control Opposite leaves with no hairs tapered to a point Stems with vertical lines of hairs
Mar 20, 2009 (3 WAT)
Mouseear Chickweed
Mouseear Chickweed Eastern NC winter annual Western NC perennial Hard to control with standard 3-way herbicides Opposite leaves, dark green with soft hairs Small white flowers with 5 slightly notched petals
Large Hop Clover
Large Hop Clover Many-branched winter annual easy to control Trifoliate leaves with prominent veins and the terminal leaflet on a short stem Short, hairy, reddish stems Bright yellow flowers in clusters Each flower produces a single seed
Apr 25, 2006 (6 WAT)
Carolina Geranium Seedpods resemble stork beaks
Carolina Geranium Winter annual sometimes called cranesbill because of the fruit beak characteristic Leaves deeply 5 to 7 lobed and bluntly toothed Pink to lavender flowers Easy to control
Henbit: Easy to control with sulfonylurea herbicides; otherwise difficult to control unless treated in the fall when seedling Square stems Purple flowers
Henbit Very common winter annual Square purplish-green stems upright but can root at the nodes Leaves rounded, coarsely toothed, hairy and deeply veined; upper leaves lack petioles Flowers with purple petals fused into a twolipped tube
Trimec Classic 3.5 pt/a: Apr 11, 2005 (4 WAT)
% Control Henbit control averaged over 1997-2007 100 80 Millenium Ultra 2 1-1.25 qt Escalade 2 1-1.5 qt Trimec Classic 1.5-1.75 qt 60 40 50 39 38 43 42 Confront 1-2 pt Coolpower 1-1.5 qt 20 0 Rates are product per acre, averaged across formulations, locations, years.
Check Escalade 2 4EC 3 pt/a Applied 10-22-09 Photo 11-17-09
Purple Deadnettle: Control concerns as henbit Square stems, purple flowers as henbit Upper leaves on short petioles and reddish-purple
Knawel
Knawel Winter annual broadleaf weed that looks like a grassy weed upon germination Leaves opposite, linear and sharply pointed Inconspicuous green flowers clustered in leaf axils somewhat spiny to the touch Easy to control
Parsley-piert
Parsley-piert Low growing winter annual easy to control Leaves alternate and palmately dissected (3 lobed with each lobe 3 lobed) Leaves with cone-shaped stipules at the base that encircle the stem Inconspicuous flowers clustered in leaf axils
Corn Speedwell
Corn Speedwell Low growing winter annual moderately difficult to control (a few herbicides provide good control) Thrives in open, thin turf Entire plants covered with soft, fine hairs Small flowers bright blue Seedpods heart-shaped
Lawn Burweed (Spurweed)
Lawn Burweed (Spurweed) Low growing winter annual moderately easy to control Leaves opposite and twice pinnately dissected Inconspicuous flowers Seeds with sharp spines
POAAN controlled Burweed unaffected
Field Pansy Johnny-jump-up Violet
Field Pansy (Johnnyjumpup Violet) Winter annual with erect stems up to 5 tall Leaves alternate with dissected stipules Flowers borne on prominent stalks Flower petals white with blue veins or entirely blue to bluish-violet Moderately difficult to control (SU s effective)
Summer Annual Broadleaf Weeds Germinate in the spring or early summer (frequently germinate after mid-summer rains) Can quickly flower in 3 to 4 weeks after germination from midsummer rains Survive close mowing because of prostrate growth habits
Summer Annual Broadleaf Weeds Some SA weeds may be controlled with preemergence herbicides when applied before expected germination. Postemergence control can be achieved with combination products containing two, three or four broadleaf herbicides. Postemergence control is best on young weeds in late spring or early summer. This also gives the turfgrass a chance to recover in areas occupied by the weeds at this time.
Prostrate Knotweed Dull bluishgreen leaves
Prostrate Knotweed Low growing summer annual easy to control Commonly found in infertile, compacted soils Tough, wiry, slender stems from a tap root that produce a mat-like growth habit Inconspicuous white flowers borne at the nodes
Lespedeza
Lespedeza Low growing summer annual can thin out turf Tough, wiry, hairy stems from a tap root that produce a mat-like growth habit Difficult to control with older 3-way herbicides Trifoliate leaves dark green Pink to purple flowers borne at the leaf axils
Jul 5, 2006 (4 WAT)
Prostrate Spurge Aug 2, 2006 (5 WAT)
Prostrate Spurge Low growing summer annual fairy easy to control Reddish-green stems from a tap root that produce a mat-like growth habit and emit a milky juice when broken Can choke out thin turf Leaves opposite usually with conspicuous maroon blotch Pinkish-white inconspicuous flowers borne at the leaf axils
Perennial Broadleaf Weeds Perennials are capable of living more than 2 years. They thrive in weak, thin turf. They spread primarily by seed, but can reproduce vegetatively through organs such as: Fleshy taproots dandelion and dock species Creeping stems white clover and ground ivy Stolons India mock strawberry Rhizomes wild violet, dollarweed
Cool Season Perennial Broadleaf Weeds Post-emergent control with combination products containing two, three or four broadleaf herbicides Post-emergent control is best on young perennial weeds during October November. You can also receive good control from March April when plants begin new spring growth. Perennial weeds generally require 2 or more applications for effective control.
Warm Season Perennial Broadleaf Weeds Post-emergent control with combination products containing two, three or four broadleaf herbicides Post-emergent control is best on young perennial weeds during May June before reproductive structures are allowed to form. Perennial weeds generally require 2 or more applications for effective control.
Buckhorn Plantain
Buckhorn Plantain Fibrous-rooted perennial easy to control Leaves basal, long and pointed with several prominent parallel veins; back of leaves deeply creased or ridged because of veins Flowers arranged in a dense terminal spike
Wandering Cudweed Cudweed Species Purple Cudweed
Cudweed Species Cool season biennials easy to control Control in fall or early spring before seedhead formation Seedheads covered in distinct fine white wooly fibers that help them disperse
Dichondra Kidney shaped leaves nearly circular
Dichondra Perennial that spreads by creeping stems that root at the nodes mod. difficult to control Greenish-white flowers borne in clusters in leaf axils
Catsear (Hairy leaves) Dandelion Species Common (Hairless)
Nov 29, 2006
Nov 29, 2006
Dandelion Cool season perennial with thick, fleshy taproot Easy to control Leaves grow in a rosette from the crown Leaves long, narrow with irregular lobes pointing toward the crown Leaves purplish at base and emit milky substance when broken
Dandelion Deep golden yellow flowers on heads of long hollow stalks Blossoms mature into spherical clusters of whitish fruits (puffballs) made of parachutelike seeds spread easily by wind
Dollarweed (Lawn Pennywort) May 19, 2005 (4 WAT)
Dollarweed (Lawn Pennywort) Warm season perennial with fleshy scallopedshaped leaves attached to underside of long stalks to form an inverted umbrella shape Reproduces by rhizomes Easy to control with sulfonylurea herbicides but takes two applications Mainly suppression with 3 or 4 way herbicides
Florida Betony
Florida Betony Hard to control cool season perennial Postemergence in Oct and Mar for fair control White tubers resemble rattlesnake rattle Square 4-sided stems White to pink flowers
Ground Ivy
Ground Ivy Perennial with creeping stems that root at the nodes moderately difficult to control Thrives in sun or shade Opposite leaves round, scalloped along the margin and heavily veined on upper surface Square 4-sided stems Funnel-shaped bluish-violet flowers in leaf axils
India Mockstrawberry
India Mockstrawberry Cool season perennial spreads by hairy stolons Moderately difficult to control Leaves alternate and trifoliate Leaflets toothed and hairy, hairy petioles Flowers with 5 yellow petals from leaf axils Red and fleshy fruit similar to commercial strawberry but smaller and tasteless
Virginia Buttonweed Mottles yellow mosaic leaves
Virginia Buttonweed Warm season perennial mod. difficult to control Stems hairy along the ridges Opposite leaves without petioles White flowers sometimes with pink streaks in the center borne in leaf axils Fruit with 4 membranous sepals at the tip
White Clover
White Clover Cool season perennial with creeping stems that root at the nodes easy to control Trifoliate leaves on long petioles surrounded at base by membranous sheath Leaves usually with white crescent-shaped water marks White to pink flowering heads on long stalks, 0.5 to 1.5 inches in diameter
Common Yellow Woodsorrel
Common Yellow Woodsorrel Perennial with shallow taproot Very short stolons Hairy stems Alternate trifoliate heart-shaped leaves 2 to 9 bright yellow flowers with 5 petals Fruit a narrow capsule 0.5 to 1 inch in length
Wild Violet
Wild Violet Cool season perennial difficult to control Spread by rhizomes Large heart-shaped leaves Flowers mostly purple with five petals Found mostly in shady habitats
Wild Garlic
Wild Garlic Cool season perennial with garlic odor Mod. difficult to control (Oct-Nov or Feb-Mar) Develops from basal bulb Hollow and round leaves Greenish-pink to purplish flowers borne in clusters at stem tips often mixed with small aerial bulblets
Mosses
Mosses Branched, thread-like primitive forms of plant life difficult to control (non-vascular plants) Form thick green mat on soil surface Competitive in cool, moist, shady conditions Spiking, coring, raking to alleviate compaction helps with control
Conclusions An effective weed management program begins with a vigorous turf; one that is correctly fertilized, watered and mowed. Cultural management practices that enhance turfgrass growth generally reduce weed competition and encroachment. Chemical control is also an option, but should only be considered after proper cultural management practices have been implemented.
Conclusions If weedy species persist, it is important to properly identify the weed and select the right chemical for control. Pesticides should be the last line of defense against weeds, not the first. Always remember, a dense aggressive turf is the best defense against weeds!!