Invasive plants along our roadside , in our raw areas , or on our own property destroy natural habitats . Great hulks of loop vines obliterate the identify of tree and shrub . Hikers are obturate by stands of setaceous , vine - wrapped , dense thickets . homeowner are now fight the encroachment of stiltgrass and wavyleaf forage in their lawns . Eradicating encroaching plants can be a discouraging , costly , time- and parturiency - intensive battle . All these foreign-born invasive industrial plant share a terrible power toreproduce prolifically and outcompete aboriginal plants . The change they imposethreaten the existence of insects , birds , and wildlife .
This treatment calendar is based on data compiled byBlue Ridge PRISM(Partnership for Regional Invasive Species Management , Inc. ) . This voluntary - push , non-profit-making organization is commit to cut back the negative impact of invasive plants in the northerly Blue Ridge Mountains of Virginia . For more information about the history of the organization , its commission , and the service it provides , seeBlue Ridge PRISM .
Many of these foreign-born plants will be familiar to you ; some are not . Many are still sell in the trade wind by nurseries and plant purveyors because they are deemed to have decorative beauty . But do n’t let visual aspect deceive . These plants are a scourge whose riffle issue will pass off from one decade to the next . For a brief discussion of the legislative process for controlling incursive plants , see“Don’t Buy Nonnative Invasive Plants – Even If you’re able to . ”
The goal of this calendar is to furnish an easy reference for identifying WHEN to treat WHICH encroaching . This goal is complicated by the fact that there are oftenmultiple case of treatmentsrecommended for each invasive depending on several factors : thetime of the year , the area in which the invading grows , and the stage of plant adulthood . This mean thatmany invasives can be treat at dissimilar time of the year and will appear in more than one control calendar month .
The following examples illustrate how control method are influenced by multiple factor :
This calendar summarize the information allow in the PRISM fact sheets ; please refer to these Fact Sheets for more in - depth info on plant characteristics , environmental impact , and multiple intervention choice . To seethe PRISM Fact Sheets on each flora and exposure for identification , dawn on the link highlighted in the plant life ’s name . For a description of different control methods , seeBlue Ridge PRISM / Fact Sheets / Control Methods . For type and amounts of the urge herbicide , Blue Ridge PRISM refers toVa . Dept . Forestry / Non - Native Invasive Plant Species Control Treatments .
NOTE ON HERBICIDES : THE LABEL IS THE LAW . READ THE LABEL . Carefully prepare and apply herbicides grant to recording label directions ; apply the minimal amount of recommend weed killer that will be effective for a particular situation . Be aware that the labels can change ; refer to label for updated information .
We would all care to void weed killer , but these invasives are so fertile and so relentless , thatherbicides are often necessary . To downplay the manipulation of herbicide , use a paintbrush approach path or a spot lotion whenever possible rather than a foliar spray . If a foliar spray is the most effective method , woody shrubs can be cut back first to minimize the amount of herbicide that ’s needed . When using the cut stump method for enceinte diameter trunks and vine , weedkiller can be paint 1″ around the inner border of the cut stump rather than on the entire airfoil . ThisVIDEOdemonstrates how to use a paintbrush overture with the cut stump method acting . Be cognisant that cut stump , hack and jet , and basal bark treatments necessitate a much higher compactness of an herbicide ’s alive ingredient ( a.i . ) than any foliar sprayer . Using foliar spray concentration for cut stump , etc . will be ineffective . See thisBlue Ridge PRISM articlefor instructions on how to safely and effectively apply herbicide .
INVASIVE WATCH BY MONTH
FEBRUARY
Paradise Tree or Tree of Heaven(Ailanthus altissima)is a nonnative invasive that menace natural surface area , farming field of study , disturbed areas , and develop landscape . Ailanthus is a particularly authoritative target plant because the nonnative insect pest , Spotted Lanternfly , prefers , and may even require , A. altissimatrees to complete its lifecycle . A spotty lanternfly plague has the voltage to severely damage Virginia ’s orchard crops and canopy trees . Small ailanthus saplings , up to about 3 ’ , can ordinarily be manus pulled or foliar sprayed . If the stalk is too big to hand tear , try breaking it with your hand . The Sir Henry Wood is very brittle and breaks easy . Apply concentrated herbicide to the end of the broken shank . This can be done all class , except during foliage out . If the stem is too stocky to break , use the rationalise stump technique applying herbicide directly to the cut . The basal barque treatment can be used for tree with 4 - 6 ” stems . The political hack and squirt technique can be used on fore that are 4 ” in diam up to ripen trees . Do not utilize the hack and squirt method if the tree is situated in a high - traffic orbit ; worsening from the weed killer over fourth dimension might create a hazard once the tree falls . government note : If you are not using weedkiller and the Sir Herbert Beerbohm Tree is too big to hand draw , LEAVE IT ALONE.Without applying herbicide , ailanthus will initiate its natural selection response and father dozens of beginning sprout worsening the infestation .
Lesser Celandine or Fig Buttercup(Ficaria verna , antecedently namedRanunculus ficaria ) grows so densely and so apace that it forms a uninterrupted heavyset mat of leaf that smothers low perennials and prevents the semen of wildflowers , grasses , and trees from germinating . A member of the buttercup family , this plant has toxic property that can have illness in livestock . The foliage burgeon forth from clandestine radical and tubers and appear in tardy wintertime before anything else greens up . Flowers begin blooming in March or early April and stop when the atmospheric condition becomes hot . When blooming finish , the leafage white-livered and the plants go dormant . low infestations of lesser celandinecan be controlled by hand dig when the soil is moist . Care must be take away to slay as much of the plant material ( including all root material , bulblets and tubers ) as potential . For with child infestations , apply foliar applications of herbicide to lesser celandine during the later wintertime through the early spring ( February - March ) before aboriginal plants issue . less celandine is unremarkably found develop near to water ; in this case , use an aquatic - approved glyphosate applied at a rate of 1.5%-2.0 % . Despite its invasive property , F. vernais still commercially sell by nurseries and plant life purveyor .
MARCH
Asian or Oriental Bittersweet(Celastrus orbiculatus ) is a ramose , deciduous vine with woody halt that can scale Tree up to 60 ’ eminent . stem of quondam vines are commonly 4 ” in diameter . Be measured with designation ; Asiatic bittersweet close resemble American bittersweet ( Celastrus scandens ) , a relatively rare native . In fall , the fruits plow red and remain in winter when they are eaten by bird and dispersed to other locations . hired hand draw out small vines in spring when the dirt is moist . Be certain to remove the crownwork and all large roots or vigorous Modern growth will occur . Low bushy vine or resprouted vines can be obliterate with a foliar herbicide spray after leaves appear in natural spring through fall . Be mindful of native plants grow in the area . It is best not to spray large vines . From fall to wintertime , use the emasculated stump method acting with herbicide employ immediately to the cut or habituate the plug and squirt method when vine are large enough .
Garlic Mustard(Alliaria petiolata ) has displaced native wildflowers such as springiness ravisher , wild ginger , bloodroot , trillium , and toothworts in many forested areas . Although this works is easy to recognize after it produces snowy flowers in early April , its leafage is also distinctive , and all portion of the plant emit a strong garlic odor . It iseasy to pull in spring when the ground is moist . If the infestation is too expectant for hand pulling , daub - spray the rosetteswith a recommended herbicide any prison term the ground is not frozen . It is indispensable to remove garlic mustard before it sets semen in May - September .
Mile - a - Minute(Persicariaperfoliata ) is an annual vine and prolific seeder that can produce 6 ” a day and reach heights of 25 ’ in a undivided season . Tiny , recurved , needle - piercing barbs gird its leaves and stems . Clusters of tiny , livid flowers look in June follow by green fruits that mature to brilliant low-spirited . Seeds of green fruits are viable . The plant flower and fruit continually from early summer until frost . Seeds of mile -a - arcminute can float for days , earmark the noxious weed to apace invade an integral turning point . Mile - a - minute can be manually rive before it sets seed but wear mitt to protect against the shot . Foliar sprays are effective but also kill whatever is underneath the vine . Apreemergent herbicide is call for in large area of infestation . The herbicide should be lend oneself to the soilin early to mid - March before seeds bourgeon in June . Do not habituate preemergent herbicides near wetland , stream , etc . because it harms aquatic life .
APRIL
Callery or Bradford Pear(Pyrus calleryana‘Bradford ’ ) and other ornamental pears start out as popular landscape trees in the sixties and are now consider invasive in 29 state . Control trees less than 6 ’ tall with a higher - than - usual ( 3 - 4 % ) concentration of foliar spray . Foliar sprays are efficient fromwhen leaf go forth in spring until just before they begin to develop fall color . Use the standard approach for eradicating incursive tree : deal deplume pocket-sized saplings ; if too big to attract , use the cut tree stump method acting with herbicide applied like a shot to the cut ; the basal bark discourse ; or hack on and squirt . you could hand pull any sentence and practice the other approaches any time except at leaf out .
Wavyleaf Grass(Oplismenus undulatifolius ) has now overrun Virginia and appear on the state ’s noxious weed list . It prosper in shadowy sites from very moist to somewhat wry , and spreads through solution - like root word called runner . The wavy parting have the appearing of corrugate cardboard or water ripple . Pointed seed tips ( awl ) spread for miles by grabbing onto the pelt of animal and the wearing apparel of hunters and tramp . This repeated grass breaks quiescency and starts mature rapidly in April . seminal fluid shoot from April into June . Wavyleaf can be handpulled ifpopulations are small , butallbits and pieces of stolons must beremoved or they will resprout . Be sure toremove petite seedlingswhichresembleminiature , fledged plant . For larger infestation , two weed killer treatments during the same uprise season are strongly urge . Use a recommended grass - specific herbicide from April through June . This weedkiller wo n’t harm wildflowers . After June , use a non - selective herbicide ; some studies have present that grass - specific herbicides are less effective in the summer . Non - specific herbicides may also be used from April until icing , but other plant will be at risk . In wet arena or near stream , use an aquatic - dependable product . You must completethecontrol treatment before wavyleaf begins congeal seminal fluid in belated summertime .
MAY
Garlic Mustard(Alliaria petiolata ) , generally described in the March discourse part , sets cum in May - September . It is crucial to remove garlic mustard before it sets seed . Do not cut down garlic mustard when ejaculate pod are present in May - September .
Kudzu(Pueraria montanavar.lobata ) has engulfed at least 7 million acres of public and individual land in the Southeast . It is easiest to spot kudzu when its very showy cherry - regal flowers seem in late summertime to early fall . Foliar herbicide nebuliser must be employ double a year . The first nebulizer is use in tardy spring or early summerafter leave mature . The second treatment is applied in later summer or early spill . New ( modest ) irruption can be controlled without herbicide by grubbing ( pulling out by the roots ) any meter of class .
JUNE
Autumn Olive(Elaeagnus umbellata ) direct gay fields and pastures , roadsides , forest edges near mow study , and open forest . Its silver unripe leaves appear too soon in spring and last until belated spill . Red , oval yield mature in August and September . Seedlings and untested autumn European olive tree shrubscanbe hired man – pulledor dugwhen the dirt is moistif the population is notextensive . prod larger industrial plant isproblematicbecausethey resproutfrom any ascendant leftbehind . For larger and/or mature stands , foreclose seed production and dispersal bycutting back and handle plants with weedkiller by mid - Julyto keep seed ripen . Autumn olive can be controlled at any time of year , except during folio out ( spring emergence ) , by cut podium with weedkiller or hack and spurt for large stem . Watch for resprouts ; switch off and treat new stems or apply a foliar herbicide atomiser to the newfangled foliage . The basal bark method acting can also be used witha hard herbicide in a horticultural fossil oil . This is most effective in January - February or fromMay - October . Foliar sprays can be used from springiness through fall but may require a second program and may not be good . This is a very hard plant life to eliminate . See thePRISM Factsheetfor more particular .
Mile - A - moment Vine(Persicaria perfoliata , formerlyPolygonum perfoliatum ) , include in the March discourse incision , begins to bloom in June with bunch of tiny , white prime succeed by immature yield that mature to bright blue . The plant flowers and fruits continually from early summertime until hoar . Both manual pull and herbicide treatments should be done before seed setting in mid- to former - June .
Multiflora Rose(Rosa multiflora ) is a multi - cauline , circulate shrub with branched , thorny arching root word ( canes ) that can climb high into trees . Multiflora rose forms dense thickets by three methods : root at the tips of its long , arching cane ; forge fresh crowns and canes from its spreading rootage organization ; and producing abundant fruit . whitened , chicken - centered flowers blush in May and June , follow by small , strong , green fruits ( rose hip ) in mid - summer . It is good to hold in this incursive before rosehip ripen to red ink in fall . Several control methods will be necessary over several years . Pulling or grubbing ( remove by the roots ) single shrubby plants from the ground work only ifall roots are removed . Mow or mourning band whop the shrubs ( using a brush cutter , not a string trimming capacitor ) and apply a foliar nebuliser to the regrowth . you’re able to also use a cut dais method on the bush with an immediate app of weed killer to the cut . For vine that climb into trees , cut the stems closemouthed to flat coat level and paint or spray anherbicide straight off on the mown vine stump . Do not put off Japanese rose rose with aboriginal rose wine . aboriginal blush wine have pinkish , not white , blossom , as well as other different characteristics . Natives are rare and do n’t form the all-embracing sweep that you find with multiflora rose .
Tree of Heaven or Paradise Tree(Ailanthus altissima ) , in the main described in the February treatment section , can be address with thehack and spirt stump methodbest done from June 1 to October 1 .
JULY
Japanese Honeysuckle(Lonicera japonica ) is a rapidly disperse nonnative vine that competes for both above- and below - priming coat resource , inhibiting the emergence of worthy trees , bush , forage , and wildflowers . This vine retains its leaves well into wintertime ( year - round in mild climates).Handpullingyoung Japanese honeysucklein a minor areawhen the soil is moist can be effective , but any rootsleft in thesoilwill resprout . Foliar sprays are less effectual in outpouring because the herbicide does not good move from the leaves into the base during spring growing . If practicable , wait until after July 4 to address with foliar sprays . Don’t spray overhead vine . Instead , cut them near the soil any meter of yr to kill the top growth ; use foliar weedkiller to the regrowth . For the cut stump method , sever thick vines near the ground andtreat the cut ends with a recommended hard herbicidefrom early summertime into wintertime .
Porcelain - Berry(Ampelopsis brevipedunculata)is a woody perennial that is related to grapeshot and acquire so fast that it can engulf a minuscule tree diagram , such as a dogwood , in one growing season . This trespassing vine has a vast , heavy - to - drink down root system of rules . Tiny , yellow - fleeceable , ambrosia - hold in flowers are arranged in prostrate clusters and bloom June through August . They are follow by colorful clusters of shiny berries of different colors , including creamy - white , fleeceable , yellow , and lilac . These eventually mature to brilliant cobalt blue blue in September and October . Gardeners proceed to buy this plant because of its attractive berries . Herbicidal foliar discourse is most efficient when applied between midsummer and early fall . For large infestations , foliar treatments are the only viable option . To thin out the amount of herbicide needed , cut back the vines and spray the regrowth . Hand pluck works only for untested plants . It is nearly unimaginable to dig up the taproot of an established porcelain - Chuck Berry . To foreclose seminal fluid dissemination , take porcelain - berry by deplume , cutting off , or mowing from winter to midsummer , before any fruits arise for that season .
Wavyleaf Grass(Oplismenus undulatifolius ) , described more often than not in the April treatment segment , should be treated with two herbicidal foliar treatments within the same time of year . From April - June , apply a sens - specific herbicide . After June , use a non - selective herbicide;some study have shown that grass - specific herbicides are less effective in the summertime . Be mindful , however , that non - selective herbicides will put other plants at jeopardy . In pixilated areas or near streams , use an aquatic - safe product . Complete ascendance treatments before wavyleaf set out ready germ in tardy summer . If pull manually , get all portion of the stoloniferous roots .
AUGUST
Nipponese Stiltgrass(Microstegium vimenium ) forms a dim ground cover that smothers native plant and keep re-formation of woods and fields . Handpulling low infestation when the soil is moist before plants typeset seedis efficacious but trade union movement intensive . Mowing is best done just before stiltgrass heyday in August and Septemberand need be done only once if you look until then . Mow stiltgrass as low as potential , scalping the earth , to remove all above - ground parts . Foliar sprays are efficient , but the type of herbicide and the timing of app program is important . See thePRISM Factsheetsfor more detailed information .
Kudzu(Pueraria montanavar.lobata ) , loosely described in the May treatment section , is easiest to recognize when its reddish - violet peak appear in late summertime to other fall . Foliar herbicide sprays must be applied double a year . The first spray is applied in former spring or former summertime after foliage grow . The 2d foliar discourse is enforce in late summer or early fall . Treatment using thecut stump followed by herbicide treatmentis well done in late summer or other surrender . New , modest outbreaks can be verify without herbicide by grubbing ( pull out by the roots ) any fourth dimension of twelvemonth .
SEPTEMBER
Porcelain - Berry(Ampelopsis brevipedunculata ) , generally delineate in the July discussion subdivision , iseasy to spot in fallwhen clusters of different coloured berry mature to smart peacock blue bluing in September and October . Herbicidal foliar treatment is most effective when go for between midsummer and other crepuscule . For large infestations , foliar discussion is the only viable alternative . burn stump heavy vinesapplying an herbicide instantly to the cut . If you’re able to reach the largest stems in the snarl , utilize a basal barque program . Apply a concentrated , recommended weed killer mixed with horticultural oil to the lowest 12 ” of the shank ; no press clipping is needed . Be careful not to spray nearby desirable plants .
FALL / EARLY WINTER / WINTER ( October - February )
Many invasive plant areeasily identifiable in fallbecause of brightly colored berries , fall foliation color , or both . Although there are multiple treatment approaches that work at unlike clip of the yr , this subdivision describes obliteration method that are effective from fall to recent winter . These methods include cut soapbox , hack and squirt , and basal barque . The methods may be applied at any metre of the class except for other spring when the sap starts run upwardly to the leaves .
Asiatic or Oriental Bittersweet(Celastrus orbiculatus ) , generally described in the March treatment segment , is easy to spot from drop into winter due to its golden - colored foliage and bright colourize reddish berries . tag end in fall if you want to treat in the spring . It is proficient not to spray large vines ; cut stump them from drop to wintertime and immediately apply weedkiller or use the plug and small fry method . drudge and squirt is truehearted and well-off than cutting .
fall Olive(Elaeagnus umbellata ) , generally described in the June discussion department , can be effectively treat in January - February with thebasal barque methodusing a concentrated weedkiller in a horticultural oil .
Callery or Bradford Pear(Pyrus calleryana‘Bradford ’ ) , generally identify in the April treatment section , can be treated from tumble into former winter by usingcut stump , nag and squirt , or basal barque methods .
Formosan Privet(Ligustrum sinense ) is anevergreen to semi - evergreen bush , growing 15 - 30 ’ improbable , that can form large stands and heavy thickets . Although Formosan privet and all other specie of privet are invasive , they are still being sold in nurseries as hedges or privateness screen . whitened or off - bloodless blossom flower profusely in June ; blue - black , berrylike fruits seem in August and last into wintertime when they are eaten by birds and humble mammalian . Privet seedlings and low sapling can be removed by hand pulling when the grime is moist . Larger shrubs might require a Weed Wrench ® or a forest mulcher . From November to January , after deciduous plants have dropped their leafage , slue big privets down to a realizable size and apply a commend foliar herbicide at aconcentration higher thanis needed tocontrol most trespassing plants . The cut stump method with an herbicide program to the cut , os basal bark treatmentare also effective method acting and can be applied anytime except early spring .
Japanese Honeysuckle(Lonicera japonica ) , loosely depict in the July discourse section , is best treated withfoliar sprays fromautumn to early winterafter most aboriginal plants have lost their leave of absence or are hibernating , butbefore a hard freeze ( 24 ° F).For the gelded stump method , sever thick vine near the ground andtreat the swing end with a recommended concentrated herbicidefrom early summertime into winter .
Porcelain - Berry(Ampelopsis brevipedunculata)is generally key out in the July treatment section and is also include in the September section . To prevent semen diffusion , manually remove by pulling or cut down from winter to midsummerbefore any fruits grow for that season . Fromfall to winter , cut down stump bigger vinesand apply an weed killer straightaway after . If you may get through the big stems in the snarl , you canalso employ abasal bark diligence . Apply a concentrated , recommended weed killer mixed with horticultural oil to the lowest 12 ” of the stems ; no press cutting is call for . Be careful not to spray nearby suitable plants .
tree diagram of Heaven or Paradise Tree(Ailanthus altissima)is broadly speaking described in the February treatment plane section and is also admit in the June treatment section . prune down live ailanthus promotes fertile resprouting . If trees must be drop , apply a saturated , recommended water - soluble herbicide IMMEDIATELY to the top and sides of the cut stump . See the February intervention section for recommended treatment methods of stinger stump , hack and jet , and basal bark .
OTHER ERADICATION METHODS
Goat grazingis an option for some invasives such as autumn Olea europaea , Taiwanese privet , kudzu , and multiflora go up . goat will also rust desirable plants , however , and the area will generally need to be grazed forseveral sequent yearsto rid the invasives because the roots are not eaten and must be killed . herbicide can be effectively used after invasive plants resprout .
Manually pull out plants from the filth works only if all roots are removed , otherwise the ancestor will sprout new plants . This make digging larger flora particularly hard . In low – timber , hard infest fields , bombastic woody plants can be pulled with achain or a tractorbucket . In many cases , manual pulling motive to be followed by herbicide treatments . Hand pulling works best on smaller , newer infestations and when the soil is moist . Please be cognizant thatmanually rend trespassing industrial plant will disturb the dirt / foliage litter areato some degree;the act of force a flora from the soilcanbring buried seeds of that plant orother invading plants to the grunge surfacewhere they may germinate .
Mowingis impractical in a forest setting . It makes gumption only in limited condition , such as in a field of view where you might want to cut invasive sess or woody invasives at a certain time of year to prevent flowering and seed hardening . You will want to mow or bush - pig several times during the grow time of year for several or even many years . Weed whacker with strand trimmerscan be used to sheer herbaceous trespassing plants to the ground . For lesson , using a train - pruner in August - September is recommend for the mastery of stiltgrass before it sets seeded player . Be aware that gage whop may harm desirable plants along with the invasive plant life .
positive burnsor command burns can be a feasible direction to trim back the passel of vegetation so that herbicide can later be use more in effect . Multiple burn are sometimes require . Prescribed burns are sometimes used for autumn European olive tree , Nipponese honeysuckle , Chinese privet , and newer infestations of Pueraria lobata . The origin of these plants are rarely killed , so grow back must be dealt with afterwards .
source
Feature Photo : Goats Grazing on Invasives , US Navy , Petty Officer 1st Class Michael Wagoner
Leadership of Blue Ridge PRISM , Inc. ,with particular thanks to William Hamersky
Blue Ridge PRISM Fact sheet
“ How to hold in Invasive Plants : Manual , Mechanical and Biological Methods,”Blue Ridge PRISM
“ Controlling encroaching plant in effect and Safely with Herbicides,”Blue Ridge Prism
VA Dept . of Forestry Nonnative Invasive Plant Species Control Treatments
“ Do n’t Buy Nonnative Invasive Plants – Even If you may,”The Garden Shed(December 2018 )
“ Using the Buckthorn Blaster : control Invasive Plants Using the Cut - Stump Method , ” Vermont Department of Forests , Parks and Recreation
