F ield bindweed(Convolvulus arvensis L.:Convolvulaceae) is one of

the most common noxious weedsin the Pacific Northwest (PNW)and one of the most difficult tocontrol. It was introduced fromEurope to Virginia in 1739, andeven before 1900 the U.S.Department of Agriculture recog-nized the weed as a national menace.

By 1900 field bindweed wasestablished in all western states.By 1955 it was present in everyIdaho county, occupying 140,000acres of cropland. It is estimatedto occupy more than 500,000 acresof Idaho cropland plus an equiva-lent acreage of pasture and range-land. In Oregon and Washington, itis estimated to infest approximate-ly 500,000 acres in each state. Theonly noxious weed that infestsmore crop acreage is Canada this-tle (Cirsium arvense (L.) Scop.).

Field bindweed is known asmorningglory, wild morningglory,corn-bind, and creeping Jenny, butto avoid confusion with otherspecies, it should be called fieldbindweed.

Crop yields often are reduced50 percent or more where fieldbindweed infestations are dense.Field bindweed has a deep rootsystem that competes with cropplants for water and soil nutrients.Field bindweed vines climb onplants and shade them. They com-plicate tillage and harvesting byclogging machinery and entan-

Field BindweedConvolvulus arvensis L.: Convolvulaceae

PNW 580

A Pacific Northwest Extension Publication University of Idaho • Oregon State University • Washington State University

Figure 1. Field bindweed climbs upright plants, binding together all plants

within a colony or patch. Creeping in every direction, it grows in circles.

Pink to white floral petals fuse into a funnel shape.

Figure 3. Crop yields can

be reduced 50 percent or

more where field bindweed

infestations are dense.

________________

Authors—Don W. Morishita, Robert H. Callihan, Charlotte V. Eberlein,Joseph P. McCaffrey, and Donn C. Thill

Figure 2. True seedlings, at left and lower

right, emerged from seed. Upper right seedling

comes from a root stock so it doesn’t have

cotyledonary (seed) leaves.

gling plants. Agricultural landinfested with field bindweed isreduced in resale value.

Field bindweed also is commonaround home landscapes, frequent-ly infesting shrubs, gardens, andother ornamental plantings. Asnew homes are built on land thatonce was farmland, field bindweedcan continue to trouble homeown-ers, interfering with garden pro-duction and competing with orna-mental plants. It is not frequentlyfound in range or forest landunless the soil has been disturbedand seed or plant parts have beenintroduced.

State LawsField bindweed is a noxious

weed species under the noxiousweed laws of many states. InIdaho, Oregon, and Washingtonfield bindweed is considered nox-ious, although each state has aslightly different categorization ofnoxious. Currently, Idaho uses asingle designation of noxiousweeds while Oregon andWashington have multiple cate-gories of noxious weeds dependingon established criteria. Fieldbindweed in Oregon is a Class Bnoxious weed, which means that itis a weed of economic importancein areas of the state in which it isregionally abundant. InWashington, field bindweed is aClass C noxious weed, whichmeans that it is widespread in thestate and long-term control pro-grams are a county option.

Field bindweed also is designat-ed as a “primary noxious weed” inthe Idaho, Oregon, and WashingtonSeed Laws, which prohibit the saleof desirable plant seed containingseeds of any primary noxiousweed. All crop seed offered forsale in all three states must betagged to show it is free of thesepests. The tags also give the per-centage of purity and germinationof the crop seed. Clean seed ofadapted crop varieties is always agood investment.

The Idaho, Oregon, andWashington seed certification laws

prohibit certification of crop seedthat contains field bindweed seedsor that comes from fields in whichfield bindweed was found duringthe field inspection phase of thecertification process. This meansthat for control, abovegroundgrowth must be destroyed and pre-vented from producing seed.

DescriptionField bindweed and weed

species resembling it differ in leafsize and shape, flower color, andgrowth habit within and betweenpopulations (Fig. 6). However, theyall share the following characteris-tics:

Growth habit—Field bindweed isa perennial species with creepingroots and slender green, twisted,and vining stems that may grow aslong as 6 feet. When other plantspecies are absent, field bindweedstems lie on the ground. Fieldbindweed will climb upright plants,binding together all plants within acolony or patch. Field bindweednormally grows in circular patchesbecause it creeps in every direc-tion. Cultivation or other types ofmechanical or physical controlmay change this pattern by physi-cally moving creeping roots.

Leaves—Although field bindweedleaves vary in size and shape, theyalways are shaped like an arrow-head with two pointed basal lobesthat usually extend at right anglesto the leaf midvein. This is an iden-tifying characteristic of manyplants in the Convolvulaceae(morningglory) plant family. Fieldbindweed leaves have no stipulesand have a petiole (leaf stalk).

The leaf blade is usually blunt-tipped with a tiny point at its end.In some biotypes, the blade issharply pointed. Leaves are darkgreen, vary from smooth to slightlyhairy, and are usually 1/2 to 1 inchlong, but vary in size dependingupon the biotype and growing con-ditions.

Flowers—The flowers originateand grow from the leaf axils (at thejunction of leaf and stem). See fig-ures 1, 6, and 9. They have pink towhite petals that are fused into afunnel shape. The funnel shapedflowers are another identifyingcharacteristic of many plants in theConvolvulaceae family. Two tinybracts are located 1 1/2 to 2 inchesbelow each flower, and secondaryflowers can grow from buds in thebracts' axils.

Flowers are faintly scented andabout 1 inch in diameter and 1/2 to1 inch long. The exterior of eachflower has five lengthwise, thick-ened strips that may be light greenor pink. Flowers fold at night toform a 5-part twisted tube andopen during the day. Flowerblooming starts about 4 weeks

Figure 4. Leaves shaped like an

arrowhead have two pointed basal lobes

that extend at right angles to the leaf

midvein.

Figure 5. Field bindweed flowers,

faintly scented, are about 1 inch in

diameter and l/2 to 1 inch long.

2

after emergence in mid-spring andcontinues until the plant foliage iskilled by frost.

Seeds—A pure stand of fieldbindweed can produce 22 millionseeds (about 3/4 ton) per acre.Seeds are mature about 3 weeksafter flowers bloom, but have beenknown to germinate within 10 daysafter the flowers open. Fieldbindweed seeds have a hard,impervious seed coat that enablessome seeds to remain dormant, yetviable in the soil for many years.Bindweed seed germination hasoccurred in a field even after nobindweed seed production wasallowed for 28 years, and seedshave been documented to survive50 years.

Field bindweed seeds are con-tained in two-sectioned capsules,each with one to four (usuallyfour) seeds. Seed shape is deter-mined by the number of seeds ineach capsule, but is typically egg-shaped with one or two flat sidesand a squared-off tip at the taperedend. When four seeds form, eachone has two flat sides and onerounded side. When two seedsform, they have only one flat side.Occasionally, capsules have singleseeds; these seeds have no flat-tened side. Seeds are grayishbrown to black and have a rough,pebbly surface.

Seeds are about 1/8 inch (3 mm)long. This, combined with theirvariable shape, makes them verydifficult to separate from wheat,barley, and other seeds in seedcleaning equipment. As a result,field bindweed seeds are commoncontaminants in these crops.

Roots—Field bindweed spreadsprimarily by roots when weed con-trol practices suppress floweringand where tillage implements carryroots to uninfested areas. Buds atvarious intervals along the rootssend up shoots creating new plantsaboveground. Roots spread outbelowground laterally from a fieldbindweed and also can penetrate20 feet deep in soil, but normallydo not send up shoots from any

deeper than 2 feet. Studies haveshown that root systems increasein vigor and regenerative ability asroot diameter increases and as theroot gets older. Buds on brokenroot segments as short as 1 inchcan produce new shoots.

Another factor affecting the abil-ity of a root segment to re-grow isthe depth from where the root seg-ment originated. Fragments takenfrom below the plow layer aremuch more likely to grow thanfragments taken from the top 2 to4 inches, due to the lack of budsabove the plow layer.

Seedlings—Field bindweed seedgerminates in the fall and spring.See figure 2. The optimum germi-nation temperature is 86°F and canrange from 34°F to 104°F.Bindweed seedlings can be identi-fied easily by their two cotyledons(seed leaves) shaped like kidneysor hearts.

As soon as the plant begins pro-ducing true leaves, their outline isthe same arrowhead shape asleaves on a well established plant.Seedlings develop a deep taprootabout 6 weeks after emergence.More importantly, at approximatelythe same time—6 weeks afteremergence—these plants can alsobegin producing underground root-stocks capable of producing newplants from vegetative buds.Therefore, mechanical controlsuch as tillage or hoeing can beeffective for seedlings only duringthe period from emergence to 6weeks after emergence. After thisperiod, when field bindweed plantsdevelop lateral roots, the plantsresist mechanical control, but usu-ally are not difficult to control withherbicides until they are two tothree years old.

Similar speciesHedge bindweed—Calystegia

sepium (L.) R. Br. is in the samefamily and occurs in waste areasand fencerows. It is nearly identi-cal to field bindweed, but hasmuch larger, hairless leaves andflowers that measure 1 1/2 inches

across. At the flower base, twolarge but not overlapping bractsenclose the flower calyx (greenprotective covering of a bud).

Hedge bindweed has beenreported in the Idaho counties ofGem and Bingham in 1989 and2001, respectively. It is more com-mon in western Oregon andWashington. Several otherbindweed or morningglory speciesoccur in the United States, butnone has been reported in the PNW.

Annual morningglory—

Ipomoea purpurea (L.) Roth,another member of the morning-glory family, is a related, commer-cially available ornamental speciesthat is rarely weedy in the PNW.Varieties of this species have muchlarger, showy flowers of variouscolors. Because it is an annual, it ismore easily controlled by mechani-cal means such as cultivation. Thisspecies is also a weed in manyother parts of the country.

Wild buckwheat—Polygonum

convolvulus L., is a member of thePolygonaceae or buckwheat fami-ly, and is sometimes called blackbindweed. This annual weedoccurs throughout the PNW andoften is mistaken for fieldbindweed. Wild buckwheat has atwining growth habit and leaf sizesand shapes similar to those of fieldbindweed, which is why thespecies are often confused.Buckwheat is distinguished easilyby the following characteristics:(1) untwisted, often red or whitestems, (2) tiny, inconspicuous flow-ers in groups at the leaf axils, (3)an inconspicuous papery sheaththat encircles the stem at the baseof each leaf petiole, (4) leaf bladeswith basal lobes that point down-ward and (5) long, very pointedleaf tips that do not vary in shape.

Each wild buckwheat flower hasa single seed that is distinctly trian-gular in cross-section, with sharpangles and sharply pointed ends.The plant is not unusually hard tocontrol and seldom occurs outsideof cropland, gardens, or ornamen-tal plantings.

3

Silver lace vine—Polygonum

aubertii Henry, also in thePolygonaceae family, has woodystem bases and may climb as highas 30 feet on trees and poles. Itsleaves have nearly the same sizeand shape as field bindweed leaves,but they have sharp, narrow tipsmore like those of wild buckwheat,and distinctively ruffled edges, espe-cially when young. The flowers aresmall and in showy bunches. Silverlace vine is uncommon in the PNW.It is sold as an ornamental andsources can easily be found on theInternet. It is described as a ram-pant, twining vine that produces acloud of white flowers and is valuedfor its adaptability, not its refinement.

Many other species have leafshapes similar to field bindweed,but lack twisted, vining stems.

How Field BindweedSpreads

The primary means of long-dis-tance spread is by seed, but once aseedling becomes established, apatch or colony forms and spreadsby extending lateral roots. Thespreading root system enablesundisturbed patches in crops toenlarge 6 to 10 feet in diameter peryear. As previously mentioned, suchpatches tend to be circular.

Under favorable soil moistureconditions, new infestations can

occur when field bindweed contam-inated soil is moved or when fieldbindweed root sections are trans-ported by agricultural or construc-tion equipment from one location toanother.

Field bindweed seeds can passthrough animal digestive systemswith little or no damage. Grains orforages containing mature fieldbindweed seeds should not be fedto animals unless the feed is groundor otherwise processed to destroythe seeds.

Effects on LivestockAlthough field bindweed is not

productive forage, sheep havegrazed and eaten it in the United

Figure 6. See field bindweed and species resembling it. Distinctive differences in field bindweed compared to simi-lar weeds are labeled. Growers will want to eliminate all of these from crop, pasture lands, and from home landscapes.

Hedge bindweed

Large bracts enclose flower base

Leaf: Sharply pointed. Blade up to 8 inches long. No stipules. One leaf per

node.

Flower: 1 l/2 to 2 inches across. 2 to 3 inches long. White to pink. Bracts are

large at base of petals. Distinct points on calyx lobes.

Stem: Green, very slight twist.

Russian vine

Ruffled edge

Leaf: Sharply pointed, up to 2 l/2 inches long. Ruffled edges. Rounded basal

lobes. Sheathing stipules. Two or more leaves per node.

Flower: Small, white, in profuse bunches.

Stem: Brown woody lower part. Green upper part, not twisted.

4

Wild buckwheat

Narrow, sharp point

Sheathing stipule

Leaf: Arrow shaped. Sharply pointed. Basal lobes point opposite to leaf tip.

Up to 3 inches long. Sheathing stipules. One leaf per node.

Flower: Small, green to white, inconspicuous, one triangular seed per flower

Stem: Red to white, not twisted.

Field bindweed

Small bracts well below flower

Leaf: Arrowhead shaped, up to 2 l/2 inches long, tiny point in rounded leaf

tip. Basal lobes point at nearly right angles to midrib. No stipules. One

leaf per node.

Flower: Funnel-shaped, up to 2 l/2 inches long, 3/4 to 1 inch across. White to

pink. Stalk has 2 bracts l/2 to 2 inches below the flower. Flower folds at

night.

Stem: Twisted, green.

States with no reported ill effects.Continuous, intensive sheep grazingover a period of several years cantemporarily suppress fieldbindweed. Afterward, however, itwill recover fully if undisturbed.More importantly, grazing that isintensive enough to control fieldbindweed usually destroys desirablegrass species as well, opening theway for erosion and more weedinvasion.

Cattle do not readily graze fieldbindweed, and hog poisoning fromfield bindweed consumption hasbeen reported. Other members ofthe Convolvulaceae family havebeen reported to possess purgativeproperties and have caused cattle,goats, and sheep to become ill,although the illness has not beenclearly defined. As a result, eventhough small amounts (5 to 10 per-cent by weight) of field bindweed inan animal's diet have produced noreports of adverse effects, heavygrazing on dense stands of fieldbindweed appears to be risky.Allowing livestock to eat fieldbindweed after seed maturity canresult in weed spread since seedscan pass through livestock and ger-minate. Any transport of noxiousweed seeds, even in animals, vio-lates many states' noxious weedlaws.

Control andManagement

Since field bindweed seeds cansurvive in the soil for manydecades, total eradication is not arealistic short-term goal whereseeds lie dormant. However, withdiligence you can eliminate fieldbindweed root systems by integrat-ing the use of biological, mechani-cal, and chemical control agentsinto certain cropping or land man-agement practices. When only themore easily controlled seedlingsgrowing from seed remain, a fieldbindweed infestation causes negligi-ble economic losses. The best con-trol methods and materials dependon the size of the infestation and theconditions under which the weed isgrowing. Using a combination of

control strategies will provide thegreatest chance for success.

Biological controlCompetition—Perennial grassescan compete well with fieldbindweed. Most of these grassesbegin growth much earlier in theseason than field bindweed does,and can take early advantage of lim-ited soil moisture and establish acanopy that competes with fieldbindweed for light.

Bindweed will persist in range-land, pasture, and lawns in a sup-pressed condition and will grow vig-orously if competitive species areabsent, overgrazed, or mismanaged.Enhance competition from desir-able grasses by avoiding early andmid-spring grazing or by grazing allplants in a short duration highintensity system, applying nitrogenfertilizer, and reseeding where needed.

Alfalfa can be used to contain afield bindweed infestation, but willnot crowd it out. Alfalfa may, how-ever, be used as a soil-building cropin a rotation designed to controlbindweed by other means. This maybe especially useful under drylandconditions.

To obtain maximum benefits

from any cropping method, growhealthy, vigorous crops. For maxi-mum crop yield, test the soil todetermine crop nutrient needs, andapply the necessary fertilizer. Thiswill improve the crop’s competitiveability and help suppress bindweed.

Insects and Mites—Organismsfor biological control are underinvestigation, but have not yetresulted in substantial fieldbindweed control. Several insectand mite species attack fieldbindweed in its native Europeanand Asian habitats. Some of thesespecies already exist in the UnitedStates and Canada. However, manyinsects that feed on field bindweedalso damage native and ornamentalmorningglories (Ipomoea andCalystegia spp.) as well as sweetpotato (Ipomoea batata). The U.S.Department of Agriculture willapprove the release of those insectand mite species that damage fieldbindweed only. The single importedinsect that has been tested success-fully and approved for release inparts of the United States is theEuropean moth (Tyta luctuosa).Caterpillars of this moth defoliatebindweed, usually in the later partof the growing season. This is

5

Figure 7. A pure stand of field bindweed can produce 22 million seeds (about

3/4 ton) per acre. Seeds mature about 3 weeks after flowers bloom, but have

been known to germinate within 10 days after flowers open.

unlike the other moths, Bedellia

and Emmelina, which feed early.This moth has not been released ona large scale to date; thus, its biolo-gy and impact under U.S. conditionsare unknown.

A gall-forming mite, Aceria mal-

herbae, has become established inTexas, and has had greater successin the southern U.S. Its feedingdeforms field bindweed buds andleaves. The insects and mitesdescribed here are unlikely to pro-vide satisfactory control unless theywork together with other agents.

Field bindweed control withinsects and mites is not promisingin an annual cropping system, gar-dens, or turf. The extensive rootsystem, which limits control byother methods, also limits the abili-ty of insects and mites to controlthis weed. In conventional annualcropping systems and gardens, bio-logical control agents do not controlfield bindweed because they areseriously damaged by insecticides,tillage, and other farming and gar-dening practices. Eventual use ofbiological control agents is expect-ed to be limited to range, pasture,forest, and other noncrop areas.

Insects that occasionally dam-

age field bindweed—A leaf-min-ing moth (Bedellia somnulentella)and a defoliating moth (Emmelina

(= Oidaematophorus)monodactyla) occur in the PNWand other parts of the United States.These insects may attack bindweedearly in the season and can some-times cause significant damage.Parasitism and predation of thesemoths by other insects limit theireffectiveness. These moths have abroad host range that includessweet potato, discouraging their useor further distribution for biologicalcontrol in the United States.

The golden tortoise beetle(Metriona bicolor) and other tor-toise beetles are commonly foundon native morningglories and some-times on field bindweed in the west-ern United States. Feeding by adultsand larvae generally results inminor damage to weed foliage.

Mites occasionally damage field

bindweed—The two-spotted spidermite (Tetranychus urticae) andother mites can cause considerabledamage to bindweed foliage.Unfortunately, this damage sup-presses the plant little because itoccurs late in summer. These miteshave a broad host plant range thatincludes many important cropplants and are not considered valu-able for field bindweed suppression.

Mechanical ControlFallow tillage works when

consistent 3 to 5 years

Field bindweed control by tillagerequires 3 to 5 years of consistent,frequent tillage. Field bindweedstores its food reserves in the rootsand will yield only to a thorough,well-timed tillage program. The besttime to start a tillage program isimmediately after harvest. It is bestto keep equipment out of isolatedbindweed patches except whenweed control operations are inprogress.

After harvest, plow 6 inchesdeep. Then, beginning 12 days afterthe bindweed re-emerges, perform atillage operation with an implementthat cuts off all of the plants such asa rod weeder or a sharp, duckfoot-type field cultivator. Make an ade-quate overlap of the sweeps every14 days until the bindweed shootsare killed by freezing. Cultivate nodeeper than necessary to complete-ly cut off all of the shoots, usually 2to 4 inches.

Clean roots and stems fromequipment before moving out ofeach bindweed patch. Resumetillage in the spring 12 days after thebindweed emerges. Repeat thistillage operation every 14 days untilbindweed no longer appears.Research shows that root segmentsin the early summer are less likelyto grow than segments from latesummer. Presumably roots from thelate summer have a higher amountof food storage built up than do theroots in early summer.

Root segments are much lesslikely to grow if tillage operationsare performed in dry soil, when norain is predicted, since low mois-

ture content in the soil willdecrease the probability of rootfragment survival. Tillage performedin dry soil will help break the rootsinto pieces that are too small togrow and will leave the root seg-ments loose from soil particles,allowing them to dry out. Fieldbindweed root fragments, whichhave been disturbed recently byother tillage methods, are less likelyto grow than root segments fromundisturbed areas. As previouslymentioned, segments in the top fewinches are less likely to grow thansegments from greater depths.

This type of tillage programrequires 3 to 5 growing seasonswithout cropping. Consistency iscrucial. A month's lapse can set theprogram back a year or more. Thisfallow program may increase ero-sion on slopes. Erosion can bereduced by planting an alfalfa-grasscrop or green manure crop to addorganic material to the soil beforetillage and by spreading organicmaterials.

Cultivation in row crops

Cultivation in row crops will sub-stantially suppress field bindweedgrowth, especially between rows,but will not prevent the weed fromcausing significant crop loss. Eventhough young stems emerging with-in crop rows may be covered withsoil thrown by the cultivator earlyin the season, many will continue togrow. Cultivation can transportroots and stems resulting in consid-erable weed spread from localizedpatches. Use other control methodsduring times in the rotation whencultivated crops are not grown.

Mowing, pulling, and burning

Removal of all field bindweed topgrowth by pulling or burning caneliminate all but the weed seed ifrepeated at least every 14 days over3 to 5 years. Mowing is inadequatebecause it misses stems lying flat aswell as low leaves and flowers, andthe plants can reproduce. Mowing iseffective only when combined withother control methods such as her-bicide treatment. Burning is mosteffective during the summerbecause damaged stem tissue

6

allows less water to leaves, stuntinggrowth of field bindweed. Burningmust be repeated like mechanicalcultivation. Any lapse in the fre-quency of these types of controlmethods will set back progresstoward eradication.

CompostingApplying manure to fields is a

common practice in many places;however, there is great concernwith the amount of weed seed thatis being applied with the manure.High temperature composting canbe an effective way to help elimi-nate viable field bindweed seeds inmanure. Studies prove that fieldbindweed seed will be killed if thetemperature of the compost reaches180°F or higher for 7 consecutivedays. If the temperature is not main-tained at 180°F or higher for at least7 days, seed viability will only bepartially reduced. For instance,compost temperatures reaching180°F for only 3 days will reducethe seed viability to 30 percent. Beaware that since the outer edges ofa compost pile may not reach tem-peratures high enough to complete-ly reduce viability, turning or mixingthe compost is essential. With smallamounts, the use of compost binsenable reaching and maintaining thenecessary compost temperaturemore easily. Smaller compostingoperations that do not meet thesetemperature and time requirementsmay kill most soft-coated weedseed, but not seed with hard seedcoats like field bindweed.

Soil SolarizationSoil solarization uses the sun's

solar energy to kill soil pests. Clearpolyethylene tarps may be usedsingly to cover pre-formed beds insmall or large areas. Weed control ismost effective when prepared bedsare irrigated before covering withpolyethylene. To prepare a bed forsoil solarization, the surface areashould be tilled and leveled.Irrigation also should be done afterthe polyethylene has been installedif irrigation drip lines are installedfirst. Moisture under the tarps helps

conduct heat and stimulates weedseed germination. The heat trappedunder the polyethylene will kill theseeds or seedlings. Soil solarizationcan suppress field bindweed topgrowth for as long as 6 weeks. Soilsolarization also will reduce thenumber of seedlings, but fieldbindweed will not be eradicatedtotally.

Field bindweed along with someother perennial weeds are hard tocontrol because their undergroundvegetative structures, like rhizomes,tubers, and bulbs, enable them tosurvive soil solarization and othernon-chemical control methods. Soilsolarization of seedling and/or annu-al weeds can be an effective alterna-tive to chemical control.

HerbicidesFor current herbicide informa-

tion, consult the Pacific Northwest

Weed Management Handbook orother publications including thelabels of specific herbicides. Anonline version of the handbook canbe found on the Internet athttp://weeds.ippc.orst.edu/pnw/weeds. This bulletin mentions onlythose herbicides that are commonlyused and currently registered forspecific site uses. New herbicidesmay become available, and currentlabel details will change over theyears. Be sure to read the labelbefore using any herbicide.

Selective herbicides

A selective herbicide is one thatdoes not normally harm desirableplants while it injures the targetplant. When hormone-type herbi-cides are used at low dose ratesaccording to label directions, theydo not harm grasses such as graincrops or lawn or pasture grasses.Long-term chemical control of fieldbindweed depends on sufficient her-bicide moving into the root systemto kill roots and root buds. Thisrequires the use of a translocated orsystemic herbicide (a herbicide thatmoves from one plant part to anoth-er). Examples of selective, translo-cated herbicides are 2,4-D, dicamba(Banvel or Clarity), picloram(Tordon), dichlobenil (Casoron),

quinclorac (Paramount or Drive),and triclopyr (Crossbow, which alsocontains 2,4-D). The translocatedherbicide glyphosate (Roundup andmany other names) is not selective,but can be used selectively withprecise application and protectionof desirable plants.

Many translocated herbicidesmove within plants along with sug-ars produced from photosynthesis.Best perennial weed control isachieved when the herbicide appli-cation coincides with maximumsugar movement to the roots. In aperennial plant newly emerged froma root bud in spring, most sugar ismoving upward to help producenew vegetative growth. When theplant reaches the bud or earlybloom stage, vegetative growthslows or stops. After that time, mostsugar produced in the leaves beginsto move toward the roots.

The bud or early bloom stage isthe best time to spray fieldbindweed provided that the plant isnot water stressed. Sugar move-ment to the roots is also high in fallas nighttime temperatures decline,so herbicide treatment of fall re-growth after harvest or tillage hasresulted in long-term control of fieldbindweed. No herbicide will beeffective if the plant has gone intodormancy or semi-dormancy due todrought, a killing frost, or otheradverse growing conditions.

7

Figure 8. Blooming begins about 4

weeks after emergence in mid-spring

and continues until frost kills plant

foliage.

Table 1. Ten ways to control field bindweed are summarizd on pages 8 and 9. With diligence, field bindweed root

systems can be eliminated by integrating the use of biological, mechanical, and chemical control agents.

8

Control type Strategies to fight bindweed plant & seeds Success notes Cautions/Problems

Biological control-

competition

Perennial grasses compete well with fieldbindweed.Alfalfa can compete with a bindweed infesta-tion, but will not crowd it out. It can be used asa soil building crop in a rotation designed tocontrol bindweed by other means (especiallyunder dryland conditions).

To enhance competi-tion from desirablegrasses: • Avoid early and mid-

spring grazing; or • Graze all plants in a

short duration, highintensity system,

• Apply nitrogen fertil-izer, as needed

• Reseed where needed.

Bindweed will persistin rangeland, pasture,and lawns in a sup-pressed condition andwill grow vigorously ifcompetitive speciesare absent, over-grazed, or misman-aged.

Biological control—

insects and mites

The USDA approves the release of insects andmite species that damage field bindweed only.By 2005, the only one was European moth (Tyta

luctuosa).

A gall-forming mite, Aceria malherbae, is estab-lished in Texas and shows success in the south-ern U.S.

Caterpillars of thismoth defoliatebindweed, usually inthe later part of thegrowing season.

Aceria malherbae

deforms field bindweedbuds and leaves.

This moth has notbeen released on alarge scale, as of fall,2005.

Control with insectsand mites is not prom-ising in annual crop-ping systems, gardens,or turf. Extensive rootsystems limit abilitiesof insects and mites tocontrol this weed.

Many insects that feedon field bindweed alsodamage native andornamental morning-glories.

Mechanical

control—fallow

tillage

FALL: Begin tillage after harvest. Plow 6 inchesdeep.• Twelve days after bindweed re-emerges, till

with an implement that cuts off all plants—arod weeder or sharp, duckfoot-type field culti-vator.

• Overlap sweeps every 14 days until bindweedshoots freeze.

• Cultivate to cut off all shoots—usually 2 to 4inches deep.

SPRING: Resume tillage 12 days afterbindweed emerges. Repeat every 14 days untilbindweed no longer appears. • Keep equipment out of bindweed patches

except during control operations.• Clean roots and stems from equipment before

leaving bindweed patch.

Fallow tillage programworks when consistentover 3 to 5 years,preferably in dry soiland without cropping.

Mechanical controls(tillage, hoeing) can beeffective for weedseedlings only fromemergence to 6 weeksafter emergence. Afterthat, lateral roots causethem to quickly spread.

Roots have less foodreserves after springemergence than in thefall.

A month’s lapse in thistillage program can seteradication back ayear or more.

Mechanical

control—cultivation

in row crops

Cultivation in row crops will substantially sup-press field bindweed growth, especiallybetween rows.

Once the crop becomes too large to cultivate,the crop must be healthy and competitive withfield bindweed.

Use other controlmethods, such as her-bicides, in combinationwith cultivation andduring times in therotation when cultivat-ed crops are notgrown.

Cultivation in rowcrops will not preventthe weed from causingsignificant crop loss.

Cultivation can trans-port roots and stems,spreading weeds.

Many young stemscovered with soilthrown by the cultiva-tor early in the seasonwill continue to grow.

Table 1. Continued.

9

Control type Strategies to fight bindweed plant & seeds Success notes Cautions/Problems

Mowing,

pulling,

burning

Removing all field bindweed top growth bypulling or burning can eliminate all but theweed seed if repeated at least every 14 daysover 3 to 5 years.

Mowing is effective onlywhen combined with othercontrol methods such asherbicide treatment.

Burning, which must berepeated, is most effectiveduring summer becausedamaged stem tissueallows less water to leaves,stunting field bindweedgrowth.

Mowing alone is inade-quate because it missesstems lying flat, low leaves,and flowers, so plants canreproduce

Any lapse in repeatedburning or mowing will setback eradication.

Composting Heat compost to 180°F for at least 7 days to killhard coated seeds such as field bindweed.

Mix compost so edge materials also heat up.

Smaller composting opera-tions that do not meet tem-perature and time require-ments may kill soft-coatedweed seed, but not fieldbindweed seed with hardcoats.

Field bindweed seed com-posted less than 7 days at180°F will survive.

Soil

solarization

Use polyethylene tarp over tilled, leveled, irrigated bed.

Can suppress top growthfor 6 weeks.

Reduces number ofseedlings, but does nottotally eradicate them.

Deep reproductive rootswill not be killed.

Herbicides,

selective

(doesn’t

harm desir-

able plants)

Consult PNW weed management handbookonline at http://weeds.ippc.orst.edu/pnw/weeds.

• Systemic herbicides include 2,4-D, dicamba(Banvel or Clarity), picloram (Tordon),dichlobenil (Casoron), quinclorac (Paramountor Drive), and triclopyr (Crossbow).

• Use translocated herbicide glyphosate(Roundup and many others) with preciseapplication and protection of desirable plants.

Time applications to coin-cide with maximum sugarmovement to the roots(late summer or early fallbefore killing frost).

Selective herbicides enabledesirables plants to bemore competitive.

See guidelines for specificcrops on pages 10 and 11.

Carefully follow labelinstructions.

Herbicides,

nonselective

(kills or

injures all

plants)

Examples: glyphosate, a systemic or translocat-ed herbicide; paraquat (Gramoxone Max), acontact or non-systemic herbicide. Revegetatewith desirable competitive plants such as peren-nial grasses.

Contact herbicides(paraquat) kill only tissuecontacted directly; can killseedlings in the cotyledonstage.

Contact herbicides onlyaffect short-term control offield bindweed top growth.New shoots can developfrom unaffected roots.

Nonselective herbicidescan kill all vegetation.

Chemical

soil

sterilants

Use soil sterilants only on noncrop sites and asa last resort. Soil sterilants do not sterilize soil;they kill or inhibit growth of plants that absorbthem.

Apply in late fall or winter (not on frozen soil),so winter moisture moves materials into thebindweed root zone. Follow label directions.

Use in areas where vegeta-tion creates a fire or safetyhazard such as electricalutility areas, remote gaspumping stations, etc.

Inspect areas treated eachyear for bindweed emer-gence, and treat againwhen appropriate/neces-sary.

Most prevent growth ofshallow-rooted weeds only,so their use may result inmore bindweed growth.

Do not use where erosioncould occur after vegeta-tion loss.

Soil fumigation can pro-vide substantial suppres-sion, but does not pene-trate deeply enough to killthe entire root system. Fumigants cannot kill dor-mant field bindweed seeds.

10

Selective herbicides bycrop, locationSmall grains—In irrigated areas,spring-planted barley or wheat com-petes well with field bindweed.Most varieties may be sprayed with2,4-D. Apply the herbicide after thegrain has tillered but before theboot stage. If weather conditionsprevent this application during thistime period, make the applicationafter the dough stage.

Under non-irrigated (dryland)conditions in winter wheat or bar-ley grown east of the CascadeMountains, 2,4-D is less effectivebecause the fall-planted crop usual-ly reaches the boot stage before thebindweed is advanced enough formost effective spraying. If possible,apply 2,4-D before the small graincrop starts to boot; 2,4-D can beapplied to winter wheat or barleyafter the dough stage if the firstapplication timing is missed. Forlong-term selective control on dry-land, use a crop rotation thatincludes at least three consecutiveyears of wheat or barley, and applythe selective treatment each year.

After small grain harvest in irri-gated fields, remove excess straw toexpose the bindweed, then irrigatethe field to stimulate active weedgrowth. In dryland areas, bindweedregrowth after harvest will dependon adequate fall rain before a killingfrost.

When bindweed stem regrowth inthe late summer/early fall is 10 to 14inches in fields where no crop isgrowing, apply 2,4-D, dicamba,glyphosate, quinclorac, or commer-cial premixed combinations such asglyphosate plus 2,4-D. The herbicidelabels will specify rates and applica-tion methods. 2,4-D is less expen-sive than dicamba or glyphosate,but residual bindweed control theseason after a single 2,4-D applica-tion averages only 30 to 40 percent.Dicamba is more costly, but is usu-ally more effective than 2,4-D. Fallapplication of dicamba results in 70to 85 percent control the next sea-son. Follow label recommendations

/restrictions for follow crop plantingafter dicamba application in the fallsince residues from high rates ofdicamba can persist in soil to injuresensitive crops the next year.

Glyphosate has no soil activity, soany labeled crop may be plantedafter a glyphosate application.Glyphosate alone has not consis-tently controlled field bindweed andin some tests has been no betterthan 2,4-D. However, combiningglyphosate and 2,4-D or dicambausually improves bindweed controlcompared with using any of theseherbicides alone. Glyphosate maybe best for spot treatment in situa-tions requiring a nonresidual treat-ment or when a field also is infestedwith quackgrass or otherglyphosate-sensitive perennialweeds.

Quinclorac (Paramount) is a rela-tively new herbicide that is used inwheat cropping systems. It shouldbe applied in the fall just prior tothe first killing frost. Fieldbindweed plants should be activelygrowing, and the above-groundgrowth should be at least 4 incheslong. In winter wheat cropping sys-tems, it is best to allow a minimumof 30 days for field bindweed to re-grow after tillage prior to applica-tion. Quinclorac can be mixed with2,4-D, dicamba, or glyphosate.Spring or winter wheat or grainsorghum are the only crops that canbe planted earlier than 10 monthsafter application. Refer to the quin-clorac label for other follow croprestrictions.

Sweet corn—Field bindweedgrowing in sweet corn may be sup-pressed with 2,4-D. However, somevarieties may be injured severely by2,4-D, so consult the label, a knowl-edgeable crop advisor, and/or yourcorn dealer or contractor beforeapplying 2,4-D. When corn height ismore than 8 inches tall, corn injurycan be reduced by using drop noz-zles to keep 2,4-D off the upperleaves and whorl.

Field corn—Field bindweed can betreated with dicamba, 2,4-D, a com-bination of both, or diflufenzopyr +

dicamba (Distinct) in many vari-eties of field corn. Dicamba may beapplied until the fifth leaf stage orcorn is 8 inches tall, whichevercomes first. Corn from 8 to 36 inch-es tall may be treated with dicambaor diflufenzopyr + dicamba, butdrop nozzles should be used toreduce dicamba drift. Do not useeither herbicide if susceptible cropssuch as potatoes, sugar beets, drybeans, alfalfa, etc., are nearby.

In corn 3 to 8 inches tall, 2,4-Dmay be used. As with sweet corn,when field corn is taller than 8 inch-es, reduce injury by using drop noz-zles to keep 2,4-D off the upperleaves and whorl. Avoid using 2,4-Desters and do not make any 2,4-Dapplications on windy or hot days.Do not allow 2,4-D to contact anyplant for which there is no labelprovision.

Some corn varieties will not tol-erate selective spraying with 2,4-D.Refer to the label or consult aknowledgeable crop adviser or uni-versity extension specialist for vari-ety tolerance information.

Pasture and rangeland—In estab-lished grass pasture, apply 2,4-D,dicamba, imazapic plus glyphosate(Journey), and picloram (Tordon)according to label directions whenfield bindweed starts to bloom.Some of the herbicides have restric-tions for returning livestock totreated areas. The limitations ofindividual herbicides are specifiedon each label.

Potatoes, sugar beets, peas, dry

beans—Apply 2,4-D and/orglyphosate the season before plant-ing potatoes, sugar beets, beans orother sensitive crops. Allowbindweed stems to grow an averageof 12 inches before 2,4-D and/orglyphosate application. These cropscannot be planted in the same sea-son 2,4-D is used.

If field bindweed has stoppedgrowing in irrigated fields, irrigatethe infested area(s) at least a monthbefore herbicide application. Spraywhen weed growth resumes andproduces 12- to 14-inch stems. Wait2 days after treatment for herbicide

11

uptake and movement within theplants, then irrigate the sprayedarea as soon as possible to maintainthe translocation of herbicides ascompletely in the plant as possible.Re-treat whenever new bindweedgrowth reaches 10 to 14 inches inlength.

Do not plow for at least 2 weeksafter herbicide application.

Orchard floors (apple, blueber-

ry, cherry, grape, nectarine,

peach, pear, prune, plum)—Fieldbindweed can be a major problemin fruit production areas, especiallyin young orchards. In addition, the20-year cycle from planting toremoval in fruit tree crops such asthose listed above, usually allowsfield bindweed to increase unlessintensive control is practiced.

In most orchards, maintain baresoil under trees and grass sod in therow middles. The use of dichlobenilas a selective residual herbicide caneffectively maintain bare soil whilea planting is becoming established.Soil-active herbicides should not be

applied around trees younger than

1 year old nor should they be

applied to shallow, coarse, sandy,

or gravelly soils. Competition fromestablished sod will minimize fieldbindweed growth in the middles.

In older plantings wherebindweed is a problem in bareareas, a paraquat/glyphosate mix-ture can be a successful nonselec-tive "burn down" treatment. Followlabel instructions. Do not let theherbicide contact immature (greenor thin) bark or tree foliage.

Roadside, fencerow, and non-

cropped areas—Maintain anadapted, competitive grass. Applylabeled herbicides as soon as fieldbindweed begins to bloom, andreapply within 2 weeks of theappearance of new growth.Picloram, dicamba, or 2,4-D may beused.

Lawns and turf—Apply 2,4-D, tri-clopyr, a mixture of the two(Turflon D), quinclorac (Drive), orother labeled systemic broadleafherbicides to fully expanded fieldbindweed leaves whenever they

appear. This application must bedone consistently over a period ofseveral years in order to destroy allroots. If the roots are successfullykilled, seedlings emerging each yearcan be controlled with these herbi-cides within 6 weeks of germinationor before the seedling produces sixleaves, whichever occurs first.

Ornamentals—Glyphosate andsome brands of 2,4-D are permittedas long as no spray mist, droplets,or other forms of the herbicide con-tact desirable plants. Extreme caremust be taken to avoid injuringdesirable vegetation. Herbicideapplication can be combined withhand-weeding for more effectivecontrol.

Nonselective Herbicides

Nonselective herbicides typicallykill or injure all plants. Selectivityhowever, is sometimes based on theuse rate. Examples of nonselectiveherbicides include glyphosate,which is a systemic or translocatedherbicide, and paraquat(Gramoxone Max), which is a con-tact or non-systemic herbicide.Contact herbicides such as paraquatkill only the tissue contacted direct-ly. They can kill seedlings in thecotyledon stage, but only short-termcontrol of field bindweed topgrowth can be achieved since newshoots can develop from unaffectedroots with root buds. Other types ofnonselective herbicides are calledsoil sterilants.

Chemical soil sterilants

Use soil sterilants only on non-crop sites and as a last resort. Soilsterilants do not sterilize the soil;they kill or inhibit growth of plantsthat absorb them. Most soil steri-lants prevent growth of shallow-rooted weeds only, so their use mayactually result in more bindweedgrowth. Soil sterilants may be usedin noncrop areas where high ratesmay be effective, but only should beused where erosion will not occurafter vegetation loss and where theherbicide will not move to sensitive,nontarget areas. Examples of wheresoil sterilants are used include elec-trical utility areas, remote gas

pumping stations, and other areaswhere the presence of vegetationcreates a fire or other safety hazard.

Apply soil sterilants in late fall orwinter (but not on frozen soil) sothat winter moisture will move thematerial into the bindweed rootzone. Follow label directions to pre-vent undesirable side effects suchas off-site movement of the herbi-cide. Areas treated with soil steri-lants should be inspected each yearfor bindweed emergence and treat-ed again when appropriate/neces-sary.

Soil fumigation can provide sub-stantial suppression, but will notcompletely kill field bindweedplants since the fumigant does notpenetrate deeply enough in the soilprofile to kill the entire root system.Deep roots unaffected by the fumi-gant can produce new shoots.Fumigants also cannot kill dormantfield bindweed seeds.

Folair nonselective herbicides

In noncrop, industrial, recreation-al, and public areas where soil steri-lants have been applied and fieldbindweed is emerging, glyphosatemay be applied nonselectively.Certain crops can be planted afterglyphosate application in theseareas. Refer to the label for restric-tions/recommendations. Picloram,dicamba, or 2,4-D also are labeledfor use in such areas at much high-er, less selective doses than theiruse rates for weed control in crops.

Prevention1. Plant seed that is free of field

bindweed seeds.

2. Ensure that roughage or grain forfeed contains no field bindweedseeds.

3. Buy nursery stock only from nurs-eries that guarantee soil aroundthe roots to be free of fieldbindweed roots and seeds.

4. Avoid mature field bindweedpatches when harvesting as har-vest operations may distributeseeds. Transport of fieldbindweed seeds in crops or onvehicles or equipment violates

Idaho, Oregon, and Washingtonstate noxious weed laws.

5. Treat all field bindweed infesta-tions appropriately in order tokill roots, prevent shoot growthfrom root buds, and to preventseed production. Use effectivemethods to control seedlings(growing from seed) in subse-quent years.

6. Be sure tractors, tillage imple-ments, harvest equipment, andother machinery are clean beforeallowing entrance onto yourland, especially if they have beenused in field bindweed-infestedareas.

7. Support laws and ordinancesthat are intended to prevent fieldbindweed spread.

Pacific Northwest extension publications are produced cooperatively by the three Pacific Northwest land-grant universities: Washington StateUniversity, Oregon State University, and the University of Idaho. Similar crops, climate, and topography create a natural geographic unit that

crosses state lines. Since 1949, the PNW program has published more than 550 titles, preventing duplication of effort, broadening the availability of faculty specialists, and substantially reducing costs for the participating states.

Published and distributed in furtherance of the acts of Congress of May 8 and June 30, 1914, by University of Idaho Extension, the OregonState University Extension Service, Washington State University Extension, and the U.S. Department of Agriculture cooperating.

The three participating extension services offer educational programs, activities and material without regard to race, color, religion, nationalorigin, gender, age, disability, or status as a Vietnam-era veteran as required by state and federal laws. University of Idaho Extension, Oregon

State University Extension Service, and Washington State University Extension are equal opportunity employers.

Published October 2005 © 2005 by University of Idaho $3.75

__________________________________

The Authors—Don W. Morishita is a University of Idaho extension weed scientistat Twin Falls; Robert H. Callihan is a UI professor emeritus; Charlotte V.

Eberlein is associate vice president and director of UI Extension at Twin Falls;Joseph P. McCaffrey is an entomologist at the UI in Moscow, and Donn C. Thill isa weed scientist at the UI College of Agricultural and Life Sciences in Moscow.

12

PESTICIDE STATEMENT ALWAYS read and follow the instructions printed on the pesticide label. The pesticide recommendations in this UI publication do not substitutefor instructions on the label. Due to constantly changing pesticide laws and labels, some pesticides may have been cancelled or had certainuses prohibited. Use pesticides with care. Do not use a pesticide unless both the pest and the plant, animal, or other application site are specifi-cally listed on the label. Store pesticides in their original containers and keep them out of the reach of children, pets, and livestock. Tradenames are used to simplify the information; no endorsement or discrimination is intended.

Figure 9. Flowers originate and grow from leaf axils at the junction of leaf

and stem. Two tiny bracts are located l l/2 to 2 inches below each flower.