Information for pest management professionals and pesticide applicators

Green Bulletinl l Vol. 2 No. 1 November 2011

Natural Herbicides: Are They Effective?

he public’s increasing demand for 0 2 T safe “green” products has resulted in 1 many new environmentally friendly herbicides for controlling weeds in the garden and landscape. Information on the efficacy of these new products is limited. However, environmental awareness groups and public agencies 14 24 72 are promoting them as a way to reduce the use of herbicides that have a greater potential to contaminate surface waters. Suppliers are beginning to more widely stock these “natural” herbicides, most of which contain essential oils or other C. A. Wilen, UC IPM natural extracts targeting weeds. Figure 1. The effect of a plant essential oil-based herbicide on grass growth 1, 2, 14, 24, and 72 hours after application. However, the grass recovered in about two weeks. The majority of these “green” weed- control products are botanically- These types of herbicides are applied be taken that the spray or drift doesn’t based oils (e.g., clove oil, eugenol, and after the weeds have emerged contact desirable or else leaf d-limonene), soaps (e.g., pelargonic (postemergent) and have little or no spotting or death will occur. acid), or acetic acid that control soil residual activity. They don’t control weeds by destroying the leaf cuticle or weed seedlings that germinate after Increasing the Odds causing cell leakage that rapidly leads application. They kill the plants by Keys for success when using these types to death. Unfortunately, because these breaking down plant membranes and of herbicides include: herbicides kill only green parts of the are considered contact or burndown plant they contact, they don’t provide herbicides. These herbicides are very fast n Good spray coverage; long-term control of weeds with acting (Figure 1), but to be most effective n Application in warm weather (75° extensive root systems or underground they must contact all or most of the to 80°F); storage structures such as , aboveground plant tissue. It is especially n Surfactants, which can improve tubers, or bulbs. Thus many treated important to spray the growing points, weed control; plants are able to recover. In contrast, or else the plant will regrow. Grasses and n Treatment when weeds are small; some conventional herbicides such as perennial weeds are difficult to control glyphosate or 2,4-D are translocated to and for an extended period of time, because n roots or underground storage structures Repeated applications for larger they have some or all of their growing weeds, in most instances. to kill larger plants and perennial weeds. points below ground.

However, in some cases, especially where Corn Gluten Meal WHAT’S INSIDE ... annual weeds are small, these products Another common natural herbicide may be appropriate. These herbicides is corn gluten meal (CGM). While NPIC Customer Help | Page 2 are best used on small weeds and annual the previously listed herbicides are postemergent types, CGM is sold as Ask the Expert! | Page 3 weeds or for controlling weeds in cracks and, in some cases, edging. They can be preemergent herbicide. Although being Alternative Turf | Page 4 used for spot spraying, but care must ... continued on Page 3 New Online Courses | Page 6 Page 2 | November 2011 D with pesticides directly throughwith pesticides their users to report injuries or problems emergencies, and NPIC asks also There section on is a handling procedures for safely using pesticides. andpets, environment the as well as andpesticides impact their on humans, information on many topics including The NPIC Web site has a wealth of Monday through Friday. hours are 7:30a.m.to 3:30p.m. PST differentlanguages. Operating pesticide-related questions in170 staffedwhocan answerby experts number, is 1-800-858-7378,which NPIC has atoll-free also telephone Unitedin the States. informationpesticide for consumers comprehensive and reliable source of at http://npic.orst.edu is most the to general the public. Its Web page andpesticides pesticide-related topics informationscience-based about University, is dedicated to providing of U.S. the EPA and Oregon State Center (NPIC), acooperative project The National Pesticide Information and interpret. foreasy nonscientists to understand oftenthe information available is not toxicity are difficult to answer, and property? Questions about pesticide applied being pesticides the to their you questions about toxicity the of o your employees or customers ask NPIC: A Good Source of Pesticide Information for Your Customers the ingredient’sthe chemistry. sheets All people want who to know more about information inalittle more depth for Technical sheets provide fact similar simple language for the general public. sheets are fact General written in no longer registered. including afew ingredients, pesticide home-use 38 common, sheets cover fact These Fact Sheets. Ingredient are Active the on site the documents Probably and most the unique useful site, www.ipm.ucdavis.edu StatewideCalifornia IPMProgram’s resources including University the of site relies primarily on to links state common home and garden the pests, toll-free phone system. For managing “ n h Uie States. United the in consumers for information pesticide of the and source reliable is comprehensive site most Web NPIC’s . more information. These are excellent sheet hasEach alist of references for likely to persist environment. inthe wildlife, and how long is pesticide the chronic toxicity to people, and pets, controls target its pests, acute and explain what chemical the is, how it help you stay up to date. information and resources that can It is frequently updated with new Entomologist, [email protected] Associate Director for Urban and Community IPMand Extension —Mary Louise Flint,—Mary Louise Ph.D., ” documents to quick reference. computer for it on your bookmark Web site and at useful this Take alook employees. customers or provide to your print out and Page 3 | November 2011

Untreated ... continued CornGlutenMeal

Handweed Area Advisor, [email protected] Advisor, Area

HouseholdVinegarVinegar Coast UC IPM South —Cheryl Wilen, soap (potassium salts of salts soap of (potassium of Examples acids) based fatty herbicides include Algae Killer, and Scythe, Moss Safer and RTU, Control 4n1 Weed Earthtone Killer. Grass and Weed Acting Fast Safer Burn- include products Combination acid). citric plus oil II (clove out Trade Names Trade oil-based essential plant of Examples Matratec, WeedZap, herbicides include Weeder, Spot Organic Greenlight Weed EcoSmart Killer, Broadleaf Bioganic EX. Greenmatch and Killer, Grass and oil ( d-limonene) orange of Examples based Avenger, herbicides include and Killer, Grass and Weed Free Worry Burndown. Greenmatch acetic acid-based of Examples herbicides (Signal word: Pharm Weed include and Weed Elimaweed Grotek Danger), Vinegar Fleischmann’s and Killer, Grass Danger; (Signal word: Control Weed food-use as the same vinegar.) this not is for acetic The acid concentration Note: 10 to be use about should herbicidal (food-use) is vinegar 20%. Household for effective isn’t 5% acetic acid and about weeds. most controlling * (3 times) (3

Preen Total Time to Weed to Time Total

Mulch

Glyphosate

5 0

25 20 15 10 Minutes * 1.5% trifluralin Figure 2. Time needed to weed landscape beds treated with various products and methods. methods. and various with products beds treated landscape weed to needed 2. Time Figure 1 Page from ... continued herbicide effective an as touted widely seedlings they as will control that numerous conducted have we geminate, been haven’t and this with product tests use justify its that results get to able herbicide. preemergent effective an as differences no were there example, For weeds in the time needed remove to CGM from with than treated plots from from or handweeded were that plants any to subjected not were that plots 2). (Figure treatment other natural Are is: So the question usedIf as effective? and safe herbicides pest management integrated an part of fit herbicides the contact program, PCA or the applicator very Also, well. the get won’t she or he that know should weed control long-term kind of same glyphosate containing products as will activity However, Roundup). (e.g., diquat by achieved be that to similar alsouser should The Reward). (e.g., based the plant of many that be aware skin cause can products “natural” or Eye problems. lung or eye, irritation, any as well as gloves and protection be should label requirements other them even if listed when using worn of some that Note products. exempt as be can quite the acetic acid products handle. to hazardous Natural Herbicides Herbicides Natural

Where can I

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Are “green” weed-control products registered I have heard a I have heard a lot about no-mow as fineleaf fescues

Some are and some aren’t. aren’t. some and are Some products control Weed natural many containing One of these species of One being ) is rubra (Festuca used in the Sacramento

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Expert! the pesticides? a low maintenance, low a low maintenance, Have a question? E-mail it to to it E-mail a question? Have . [email protected] input turf. find more information about these species? oils or food products as active active as food products or oils from be exempt may ingredients California and/ from registration These federal registration. or have won’t products “exempt” number a federal registration many However, their label. on still are products “exempt” rating a toxicity have to required or WARNING, (CAUTION, appropriate and DANGER) language. precautionary demonstration discussed in Chuck Chuck discussedin demonstration 5 4 and Pages article on Ingels’ . Bulletin Green of this issue of about more out find can You by downloading fescues fineleaf No-Mow the free publication California for Fescues Fineleaf , UC ANR Landscapes Urban Ali Harivandi, 8391 by publication California of the University from the on or catalog ANR online http://www. at site UC IPM Web ipm.ucdavis.edu/TOOLS/TURF/ ucpubs.html Page 4 | November 2011 M Alternative TurfDemonstrationProject nozzles. Thewere: species summer using Hunter MPRotator watered four days every during the (evapotranspiration); plots all were watered at 80%,60%,and 40%ETo planted is inSeptember 2010.Each threethe different were species At site, this three plots eachof plots. few weeds grewinsodded in plots that were slow in, to fill but very first inthe pulled months,few especially numbers of annual weeds were hand or are pesticides applied. being Large managed organically, no herbicides so anytime.viewed The plots arebeing canare be species the so labeled fence surrounds site, the and plots UC Master Gardeners. A4-foot Recreation and Park and District collaboration with Southgate the Extension Sacramento County in and is maintained by UCCooperative Park inSacramento. It was developed The site is located at Florin Creek Site Location and Design as sixnative grass species. under different irrigation levels as well buffalograss, and two sedge of species a standard fescue/bluegrass tall mix, determine potential their as turf are less mowing. Included study inthe to with less water and require which performwell which toturf see species (EPA) to test potential low water-use Environmental Protection Agency received agrant from U.S. the River-Friendly Landscaping program, of Water Resources, of as part its The SacramentoCounty Department unsightly. winter turf the turns when brown and in summeror or dormancy periods well, such installation as high costs can have species these drawbacks as greenhouse gas emissions. However, andenergy money as well as reduce reduce water consumption but may save alternative These may species not only planting drought tolerant turf species. and property owners are interested in any agencies, landscape managers, ... continued on the next page some late summer dormancy. middle plot 60%,and lower plot 40%ETo. Field sedge the in 80%ETo even plot showed of eachportion plot and dune sedge ( pansa) in the Top lower portion. plot 80%, Figure 2.Carex plots in early September, with fieldsedge (Carex praegracilis) in the upper watered to prevent death. a patch (far which left), later was hand fescue shows stress, severe especially in less but showed little stress, whereas tall plots 40%ETo. UCVerde in 40%ETo grew plots 80%,middle plots 60%,and lower with shading underway. also trial Top left) and tall fescue blend (above,right), Figure 1.UCVerde buffalograss (above, C. A.Ingels, Sacramento UCCE C. A.Ingels, Sacramento UCCE Page 5 | November 2011 C. A. Ingels, UCCE Sacramento C. A. Ingels, County, [email protected] County, —Chuck Ingels, County Director and and Director County Ingels, —Chuck Environmental Advisor, Advisor, Horticulture Environmental UC Cooperative Extension, Sacramento Extension, Sacramento UC Cooperative Conclusions of the one is buffalograss UC Verde reducing species for promising most plot one spray to plan We use. water in dye green biodegradable with the December overcome see can to if we winter by caused aesthetic drawback also is promising, Carex dormancy. which sedge, produces especially dune field rust than less and growth less stiff less is turf the mowed and sedge, grasses field sedge. than Severalnative least at all have but look promising period. semidormant or dormant some less are dormancy winter and Summer project This in coastal areas. issue an of 2012, through continue scheduled to is more expect we learn much and to these year. the next species during about these on information more For and species, turf photos, alternative our of the results on updates regular http:// visit plots, demonstration . UCANR.org/turfproject Figure 3. Tufted hairgrass (top, left) with (top, hairgrass 3. Tufted Figure darker and green color light characteristic With May. late right), (top, fescue Molate both summer, late in applied 60% ETo and (bottom), stress signs of showed species color. the improved watering subsequent , especially field sedge, ... continued ... went dormant in late July even in the July in late dormant went in the sedge Field plants plot. 80% ETo and fully dormant went plot 40% ETo sedge dune whereas partially brown, 2). Late (Figure still green was mostly all Carex of weights clipping summer weights. spring than less far were plots native promising the most So far, bentgrass, grasses Seashore include hairgrass. tufted fescue, and red Molate weights clipping their spring Although tall those to similar of fescue, they were fully in green not and semi-dormant are 60% to reduced was Irrigation summer. these and a period for in summer, ETo 3) (Figure species became unsightly grama Blue 80% ETo. to restored until a beautiful warm-season turf makes fully is it but tolerant, drought is and in the Central Valley. in winter dormant produces variety (unnamed) dwarf The the tall as variety half the biomass about (Hachita). 12-inch spacing resulted in some initial in some resulted spacing 12-inch set in; quickly dormancy but growth, occurred in early mowing the first were weights clipping August, In June. tall those than of fescue lower slightly in the the same plots, in the 80% ETo higher in the 40% plots. and 60% plots, 60% in the 80% and weights Clipping showing identical, nearly are plots ETo typically warm-season is turf why is stress plant No 60% ETo. at watered 1). (Figure in the 40% plot visible grasses, Sedges species) (Carex aren’t several species be can but used create to generally are turf. They excellent an tolerant very drought considered periodically be can mowed or and our demonstration left unmowed. In 9 planted were liners the Carex plot, filledin; largely have and apart inches between plants small gaps however, is growth because remain have would Closer planting slow. fairly be higher. would the costs but helped, than taller faster and sedgeField grows double in nearly resulting sedge, dune winter the wet In weights. the clipping had 2011, field sedge of spring and sedge. rust disease dune than greater Carex of Patches

); caespitosa ); pallens ), sodded; pratensis /Poa arundinacea and plugs; as ), planted dactyloides and short varieties. short and Carex sedgeCarex ( dune ) and praegracilis liners. as ), planted pansa Deschampsia (Deschampsia hairgrass Tufted ); and macrantha (Koeleria Junegrass ); hallii (Agrostis bentgrass Hall’s ); rubra fescue (Festuca red Molate Agrostis (Agrostis bentgrass Seashore Festuca (Festuca fescue/bluegrass Tall (Buchloe buffalograss UC Verde ), tall gracilis (Bouteloua grama Blue

Carex field (Carex sedge of plots Split

grows similarly buffalograss similarly grows UC Verde invasive less is but bermudagrass to rhizomes. not stolons, by spreads and and brown turns it Like bermudagrass areas. winter in cold goes dormant very pollen. produce little flowers Its so stolons in May best is planted It is weed filland growth in quickly can at Our planting September reduced. blend is frequently used, tallThe frequently is fescue blend and traffic some tolerates because it the 40% In year-round. green dark is stress water tall severe fescue plot, ETo patch in a large mid-August by appeared so the patch watered hand 1); we (Figure still could plots Carex and the UC Verde sensitive how showing 40% ETo, receive stress. tall drought fescue to is The irrigation treatments began Aug. began treatments irrigation The had plots Carex the after 1, only surprisingly, Not filled in. moderately all of weights clipping summer late with greatest species turf three were 60%, and with intermediate 80% ETo, 40%. with lowest Results to Date to Results n n n n n n n n n A “meadow” was also included, in also was included, A “meadow” grass native well-adapted which three each of plant one least at species and plots turf species used in the mowed full to size. grow to allowed were

Also included are three split plots of of plots split three are Also included species: grass California native Alternative Turf Alternative Page 6 | November 2011 UC IPMOffersNewFreeOnlineCourses I s nedd nr s rtcs ipid f similar of products notmentioned. implied criticism is nor intended, is products named of endorsement No used. been simplify information, tradeTo Program. Coordination namesEIPM NIFA USDA the of products have Statewide IPM Program with partial funding from

CA 95616,(530) 752-0495. Davis, Avenue, Shields One Resources, Natural and Agriculture Davis, California, of University to Linda Marie Manton, Affirmative Actionemployment opportunityContact, equal policies university’s may the be regarding directed Inquiries doc. prohibits http://ucanr.org/sites/anrstaff/files/107734. at California of nondiscrimination policy statement can be found complete The activities. or University programs its of any in he person any of harassment or discrimination Online: E-mail: [email protected] Phone: Davis, CA95616-8621 One ShieldsAvenue Statewide IPMProgram University ofCalifornia released inearly 2011and contains several Urban Pesticide Runoff and Mitigation was as drenching and tree injection. determining rates for injection soil as well ingredient and percentage solutions, and application equipment, with dealing active application equipment, calibrating dry Included are modules on calibrating liquid treatment area. correctthe amount of to a pesticide to calibrating eachto help you apply and provides astep-by-step approach of types application pesticide equipment training gives of an many overview from DPR category. Other inthe The andOctober approved for 1.5CEunits in turf and landscapes was released in Calibration for professionals working Pesticide Application Equipment and landscapes and situations. structural management professionals work who in andforfree pest specifically designed runoff inurban areas. These courses are andmethods preventing pesticide of courses on application pesticide UC IPMrecently aseries posted online continuing education courses. close, consider one taking of UCIPM’s license as calendar the year draws to a to renew your DPR QAL, QAC, or PCA f you find yourself a CEUsneeding few T Produced by the University of California California of University the by Produced (530)752-8350 www.ipm.ucdavis.edu Figure 1.Sample from screens available courses. about herbicides—how are they classified, This module provides informationgeneral CEUs won’t available be until early 2012. Water Quality, has just released, but been An additional component, Herbicides and n n n each available for one CEcredit: Other modules grouped into three components, Water Quality and Mitigation:

IPM—A Solution for Reducing The Impact of Pesticides on Water from site the of application. in reducing movement pesticide waterways and gives steps practical ways get into pesticides our Runoff through goes different the Quality/Mitigating Urban Pesticide movement environment. inthe and how influencepesticide they variousthe properties of pesticides is really necessary, and explains principles, a pesticide when discusses Properties teaches IPM basic Pesticides/Water Quality: Pesticide their effects. their reducing movement their or mitigating and gives somesolutions practical for waterways inCalifornia detected being two important that are insecticides Bifenthrin and Fipronil teaches about http://www.ipm.ucdavis.edu/training/. supplemental training material, go to To courses and these view the availablealso on UCIPM Web the site. calculations for calibration the course, are of eachcourse, including example Handouts highlighting key points the certificate of completion. pass afinal online beforetest receiving a screens ineachmodule all andview modules reinforce learning. Users must throughoutQuizzes narrated the and drawings to illustrate key concepts. features hundreds of color photographs of coursesEach is these narrated and protectingwhile water quality. a way that minimizesrunoff and leaching addition to tips on applying herbicides in alternative management weed in methods, reducing are herbicide discussed use. Also situation, and gives solutions practical for to choosing herbicide best the for agiven inurban waterways,detected lists steps attention herbicides to several commonly runoff and leaching.module The draws how work, they and what properties affect —Cheryl Reynolds, Interactive Reynolds, Learning—Cheryl Developer, [email protected]