1998 New England Guide To Chemical Control of Problem Weeds and Brush Around Homes and on Non-Cropland

Prepared by T.L. Mervosh, The Connecticut Agricultural Experiment Station, in cooperation with: F.J. Himmelstein, University of Connecticut; P.C. Bhowmik, University of Massachusetts; J.M. Jemison, University of Maine; J.R. Mitchell, University of New Hampshire; W.M. Sullivan, University of Rhode Island; S.C. Bosworth, University of Vermont.

NOTICE: It is unlawful to use any pesticide WEEDS - PLANTS GROWING WHERE THEY ARE for other than the registered use. READ AND NOT WANTED FOLLOW THE DIRECTIONS ON THE PRODUCT LABEL. The user assumes all Homeowners frequently find unwanted vegetation responsibilities for use inconsistent with the that we call "weeds" growing on their premises. label on the product container. Persons using Weeds can be classified by their life cycles as a “Restricted Use” pesticide must be certified annuals, biennials, perennials and woody plants. in conformity with standards set forth by state Annuals germinate, grow vegetatively, produce and federal regulations. flowers and seeds, and die all in one year. A sub- group, called winter annuals, germinates in late WARNING: and other pesticides summer or fall and flowers the following spring. may be poisonous. Read and follow all Biennials germinate and grow one season then, directions and safety precautions on labels. following a winter dormancy, flower, produce seed Wear the specified protective equipment. and die the next. Perennials live from year to year, Handle carefully and store in original labeled reproducing not only by seeds but by storage organs containers out of reach of children, pets and such as rootstocks, rhizomes, stolons and tubers. livestock. Dispose empty containers Unwanted woody plants, also known as "brush," are immediately, in a safe manner and place. Do perennial in nature. not contaminate forage, streams and ponds. Follow requirements for restricted entry WEED CONTROL ALTERNATIVES intervals and notification of pesticide application. Trade names are used for Annual weeds are shallow-rooted and can be identification. All herbicides listed in this controlled by cultural or mechanical methods such as bulletin are registered and cleared for hand pulling, hoeing, clipping or cultivating. Perennial suggested uses according to Federal weeds and brush are often difficult to control by these registration and State laws and regulations in methods because they regenerate effect on January 1, 1998.

Cooperative Extension, these universities, and the U.S. Department of Agriculture cooperating, offer education for everyone without regard to race, color, national origin, sex, religion, age or handicap. Cooperative Extension is an equal opportunity employer.

Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914; the United States Department of Agriculture and the following Extension Services:

K.M. Kerr, Director, Cooperative Extension Service, University of P.J. Horne, Director, Cooperative Extension, University of New Connecticut, Storrs Hampshire, Durham

L.L. Bartel, Director, Cooperative Extension, University of Maine, D. Caruso, Director, Cooperative Extension Service, University of Orono Rhode Island, Kingston

R.G. Helgeson, Director, Cooperative Extension, University of L.K. Forcier, Director, University of Vermont Extension System, Massachusetts, Amherst Burlington 2 from deeper underground storage organs. It is often It is best to reserve a sprayer for use only impossible to remove all of these underground and not use it for other pesticides. Even minute structures mechanically to prevent resprouting. residues in the tank can sometimes injure foliage of desirable plants. In particular, phenoxy herbicides Alternative methods of chemical control for some such as 2,4-D are very difficult to completely remove troublesome perennial weeds and brush are from spray tanks. considered below. These alternatives are available to homeowners or small farmers who are not licensed Herbicides containing (ROUNDUP (certified) applicators and who usually wish to products, ORTHO KLEERAWAY, GLYFOS, etc.) purchase only small amounts of herbicides should not be stored or applied in galvanized steel or (chemicals that control weeds). unlined steel containers or spray tanks (except stainless steel). Use in such containers could result in USE OF HERBICIDES the formation of an explosive hydrogen gas mixture which could flash or explode if ignited by open flames Herbicides, as well as other pesticides designed for or any ignition source. use on home grounds, are registered for such use by the U.S. Environmental Protection Agency (EPA) and Drift of spray particles and vapors can damage trees, state regulatory agencies. Registered herbicides have shrubs, flowers and vegetable plants. To avoid drift to been judged to be safe for humans and the non-target areas, spray only on calm days and environment when handled and used as directed on maintain large spray droplets by minimizing pressure. the herbicide label. Therefore, it is incumbent on the Avoid spraying when temperatures are above 85°F. user to carefully read and follow label directions for High temperatures can cause some herbicides to herbicide use. Care and common sense make the form vapors. difference between success and failure in controlling weeds without injuring adjacent desirable vegetation. Do not apply products containing prometon such as ORTHO TRIOX (original version no longer sold in Most of the herbicide alternatives listed here are for New England) or PRAMITOL, in the root zones of use only on non-cropland. Unless otherwise specified desirable plants. Root zones of established trees may on the product label, treated areas are not to be extend many feet beyond the spread of branches. planted to food crops for the remainder of the year in Avoid walking through treated areas until it is dry. which herbicide is applied. Herbicide picked up on footgear can cause tracking injury on adjacent turf. HERBICIDE APPLICATION METHODS CHARACTERISTICS OF HERBICIDES Details on the methods of application will be found on the labels of commercial products. Tablespoon and The active ingredients underlined below are often cup measuring devices reserved only for herbicides found in a number of commercial products. Examples can be used to measure out small amounts of liquid of commonly available products are given. Rates of products: application vary with the percentage of active ingredient in the commercial products and the weeds 2 tablespoons equal 1 fluid ounce to be controlled. Rates of application are given on 16 tablespoons equal 1 cup each of the product labels. 1 cup equals 8 fluid ounces 2 cups equal 1 pint Some herbicides are classified as selective in that 4 cups equal 1 quart they kill certain types of plants and not others. The selective herbicides 2,4-D, 2,4-DP, and Spray solutions are best applied in portable control many broadleaf weeds and brush, but compressed air sprayers but aerosols and spray not grasses. The herbicides and bottles are available for some products. Three rinses display just the opposite selectivity - they control are needed to remove residues from "empty" product emerged grasses only. Herbicides such as containers. These rinses should be added to the glyphosate and that kill or injure nearly all spray tank before application. Thorough rinsing of green plants are classified as non-selective. spray tanks after application is also essential to Glyphosate is a non-selective foliar-applied herbicide remove herbicides and to prevent corrosion in metal that is rapidly inactivated and biodegraded after sprayers. contact with mineral soils. However, phytotoxicity persists in organic matter so glyphosate should not 3 be used to control weeds on piles of potting mix containing peat. The herbicide moves systemically In the last two formulations, increases the from foliage to roots where it kills plants slowly. One speed of weed kill and oxyfluorfen provides residual to three weeks may be required for herbaceous control of weeds that emerge from seed. annuals and perennials to die. Woody plants sprayed in late season may show few symptoms until the Since uses of these glyphosate products differ, it is following spring when they often fail to refoliate. wise to carefully read the product labels before Rainfall within 6 hours after application can reduce purchase. Only the Roundup 18% and 41% (b and d) glyphosate efficacy. concentrations are registered for preplant control of perennial weeds in certain food crops. Glyphosate is the active ingredient in several different products and is available in a wide range of concentrations. ROUNDUP is the original and best Several non-selective herbicides are available that known glyphosate-based product. ROUNDUP PRO have considerably less systemic activity than and ROUNDUP ULTRA are new glyphosate products glyphosate. These herbicides range from completely that contain a different surfactant which improves the non-systemic (contact) to those that have only limited absorption of glyphosate into the treated leaf, and systemic movement within plants. All of these thus its herbicidal activity. Examples of available herbicides kill treated vegetation more rapidly than products include the following (‘glyphosate’ refers to does glyphosate. However, because a non-systemic the isopropylamine salt of glyphosate): herbicide does not move into the underground portions of the weed, most perennial weeds and ROUNDUP Ready-to-Use: 0.96% glyphosate brush can regrow. Examples of non-selective - Weed & Grass Killer herbicides include the following: - Fence & Yard Edger - Sure Shot Foam Non-systemic: ORTHO YARD BASICS SAFER Superfast Weed & Grass Killer Weed & Grass Killer (potassium salts of fatty acids) SHOOT OUT Ready-to-Use SCYTHE (pelargonic acid) REWARD ( dibromide) SHOOT OUT Concentrate 5% glyphosate Moderately systemic: ORTHO KLEERAWAY 7.5% glyphosate FINALE (glufosinate-ammonium) Systemic Grass & Weed Killer

ROUNDUP Concentrate: 18% glyphosate Phenoxy herbicides such as 2,4-D, 2,4-DP, and - Weed & Grass Killer MCPA are plant growth regulators that are found in - Tough Weed Formula several commercial products for home and farm use. They control many broadleaf weeds and brush but ROUNDUP Super Concentrate have little effect on grasses and sedges. They are Weed & Grass Killer: 41% glyphosate absorbed by foliage and stems and are moved to ROUNDUP PRO roots. Symptoms of injury include downward bending ROUNDUP ULTRA or twisting of stems, leaf cupping, and strap-shaped ACCORD new growth. Perennial weeds slowly die and woody GLYFOS plants may defoliate within 2 to 3 weeks.

ROUNDUP DRYPAK 94% glyphosate Triclopyr is the active ingredient in ORTHO BRUSH- Powder (monoammonium salt) B-GON and GARLON 3A. It is combined with 2,4-D in CROSSBOW. Like the phenoxy herbicides, triclopyr TOUCHDOWN 57.6% sulfosate is absorbed by foliage and stems, is systemic, and (trimethyl sulfonium salt of glyphosate) has little effect on grasses and sedges. Treated woody plants usually become brown and defoliate ORTHO KLEERAWAY 0.5% glyphosate + within 2 to 4 weeks. Grass & Weed Killer 0.12% acifluorfen

ORTHO GROUNDCLEAR SUPEREDGER ORTHO GRASS-B-GON Grass Killer is a ready-to- Grass & Weed Control 0.25% glyphosate + use formulation of fluazifop-butyl, which is also 0.25% oxyfluorfen available in the concentrated products FUSILADE II, 4

ORNAMEC 170, and TAKE-AWAY. Fluazifop-butyl is a selective systemic herbicide that kills only emerged annual and perennial grasses. It has little or no effect on broadleaf weeds, sedges and most broadleaf ornamental plants. One to four weeks may be necessary for treated grasses to die, and some perennial grasses may require a second application. Other similar selective herbicides for grasses include VANTAGE (sethoxydim) and ENVOY (clethodim).

Refer to the product label for recommendations on the addition of spray adjuvants or surfactants to improve activity of the herbicide. To maximize efficacy with foliar absorbed herbicides, spray on dry foliage at times when rain is not expected for several hours. 5

WEEDS TO BE HERBICIDE RATES OF CONTROLLED TRADE NAME(S)1 PRODUCT2 COMMENTS ______

1 1 1a) Perennial weeds and ROUNDUP Super Conc. 1 /2 to 2 /2 fluid Spray grasses when 6 to 8 inches tall grasses in non-crop ROUNDUP PRO / ULTRA ounces per gallon and broadleaf weeds that are actively areas or on sites to be (41% glyphosate) of water growing. Retreat regrowth if needed. planted to lawns or Delay tillage or mowing 4 to 7 days. gardens. Special ROUNDUP Concentrate 3 to 6 fl. oz. per Some weeds such as bindweed and weeds are mentioned (18% glyphosate) gallon water horsenettle require more than one below. treatment the season before planting for best results.

b) Phragmites See 1a See 1a Treat in late summer or early fall when (common reedgrass). plants are actively growing and reaching full bloom.

c) Japanese knotweed, See 1a See 1a Treat in June or later, after flowering. also called Japanese Thoroughly wet foliage. Growth fleece-flower or ceases and leaves will discolor. Do not Mexican bamboo. cut down for at least 2 weeks after treatment. Spot spray regrowth.

d) Perennial grasses (i.e. ORTHO GRASS-B-GON Undiluted Spray immature grasses when actively quackgrass, ryegrass, GRASS KILLER growing. Thoroughly wet grass blades. tall fescue) in ground (fluazifop-butyl) Retreat quackgrass in 7 to 10 days. covers, flowers, around Broadleaf weeds will not be controlled. shrubs and trees. Keep spray off turfgrasses.

e) General weed control See 1a See 1a Spray weeds during active growth. in non-crop areas and Avoid spraying turfgrasses and foliage around trees, shrubs, ROUNDUP Ready-To-Use Undiluted of desirable trees, shrubs, or flowers. and fences. (0.96% glyphosate) Avoid walking through sprayed areas until sprays dry or tracking injury will ROUNDUP DRYPAK One 1-oz. packet occur on adjacent turf. (94% glyphosate) per gallon water

ORTHO KLEERAWAY Undiluted Grass & Weed Killer (0.5% glyphosate + 0.12% acifluorfen)

1 FINALE 1 /2 to 4 fl. oz. per (glufosinate-ammonium) gallon water

3 REWARD /4 fl. oz. per gallon (diquat dibromide) water

1 SCYTHE 6 /2 to 13 fl. oz. per (pelargonic acid) gallon water

SAFER SUPERFAST Undiluted Weed & Grass Killer (fatty acid solution)

1 Trade names (in capital letters) are used for identification. No product endorsement is implied nor is discrimination intended against similar materials. See previous pages for additional product names. 2 Active ingredients are given in parentheses. 1 fluid ounce (fl. oz.) = 2 tablespoons (Tbsp.); 8 fl. oz. = 16 Tbsp. = 1 cup 6

WEEDS TO BE HERBICIDE RATES OF CONTROLLED TRADE NAME(S)1 PRODUCT2 COMMENTS ______Undiluted 2) General brush control ORTHO BRUSH-B-GON Spray all leaves to wet thoroughly. including wild Poison Ivy, Poison Oak & Products containing triclopyr or 2,4-D blackberry and Brush Killer2 or plus 2,4-DP are most effective after raspberry, sumac, Poison Ivy, Poison Oak & target brush is in full leaf and actively poplar, sassafras, Brush Killer3 growing. Products containing multiflora rose, etc. see (0.7% triclopyr) glyphosate are most effective from 3, for additional Poison 4 fl. oz. per gallon mid-summer to fall, before frost, when ivy control. ORTHO BRUSH-B-GON water soil moisture is adequate and rainfall is Poison Ivy, Poison Oak & not expected for 6 or more hours after a) Foliage sprays during Brush Killer1 (8% triclopyr) application. Triclopyr and 2,4-D plus 1 growing season. 1 to 1 /2 fl. oz. per 2,4-DP products are the better choices GARLON 3A gallon water if one does not want to kill grasses in (44.4% triclopyr) the understory. 1 1 /2 to 2 fl. oz. per CROSSBOW gallon water (2,4-D + triclopyr) 1 1 /2 fl. oz. per gallon WEEDONE 170 water (2,4-D + 2,4-DP) See 1a ROUNDUP products and other glyphosate-based products (See 1a)

5 fl. oz. per gallon b) Basal bark sprays during WEEDONE 170 of fuel oil, diesel oil Thoroughly spray lower 18 inches of dormant season. (2,4-D + 2,4-DP) or kerosene dormant stems to run down around root collar. These treatments are most 5 fl. oz. per gallon effective on brush and trees smaller CROSSBOW of fuel oil, diesel oil than 3 to 4 inches in diameter, and (2,4-D + triclopyr) or kerosene also to prevent resprouting of freshly cut stumps of any size. The herbicides are diluted in oil to facilitate entry through bark.

Undiluted c) Stump treatments to ORTHO BRUSH-B-GON Spray or paint top of freshly cut control resprouting of Poison Ivy, Poison Oak & stumps with one of these products. unwanted trees and Brush Killer1 (8% triclopyr) Treat at any time except if snow or shrubs. Undiluted water is around stumps. Stump GARLON 3A treatments may not stop sprouting (44.4% triclopyr) from root suckering species such as Diluted 1 to 1 in sumac, aspen (poplars) and ROUNDUP water sassafras. ROUNDUP PRO / ULTRA (41% glyphosate) Undiluted WEEDONE 170 (2,4-D + 2,4-DP)

1 Trade names (in capital letters) are used for identification. No product endorsement is implied nor is discrimination intended against similar materials. 2 Active ingredients are given in parentheses. See previous pages for additional product names. 1 fluid ounce (fl. oz.) = 2 tablespoons (Tbsp.); 8 fl. oz. = 16 Tbsp. = 1 cup 7

WEEDS TO BE HERBICIDE RATES OF CONTROLLED TRADE NAME(S)1 PRODUCT2 COMMENTS ______See rates for 3) Poison Ivy See products containing products in 1a, 2a Spray leaves to wet thoroughly. glyphosate, triclopyr, 2,4-D Poison ivy vines growing on trees may and 2,4-DP (1a, 2a) be treated provided only the mature bark and not the foliage of the tree is sprayed. Do not spray the bark of desirable trees with products containing oil. For vines growing in shrubs, cut off at base and treat stumps as in 2c. See 2a 4) Oriental bittersweet Products containing Triclopyr products provide excellent triclopyr as in 2a. control when sprayed on foliage. 3 fl. oz. per gallon Spray foliage to wet in August or Sept. ROUNDUP Super Conc. water before frost. For large vines growing ROUNDUP PRO / ULTRA into tree, cut off at base and treat (41% glyphosate) stumps as in 2c. Small seedlings can 7 fl. oz. per gallon be controlled by rooting out by hand. ROUNDUP Concentrate water (18% glyphosate) 0.5 to 2 lb granules 5) Total vegetation control PRAMITOL 5PS per 100 square feet Products containing prometon should and residual weed (chlorate-borate + not be used in the root zone of trees or control for driveways prometon + ) shrubs or in areas where heavy rains and walkways 1 gallon of product could wash them into turf or gardens. ORTHO GROUNDCLEAR diluted in water to TRIOX Total Vegetation treat 300 sq. ft. KillerA (oxyfluorfen + ) 1 gallon of product ORTHO GROUNDCLEAR diluted in water to Can be used in walkways or patios SUPER EDGER treat 300 sq. ft. next to trees, shrubs or turf areas. (glyphosate + oxyfluorfen) Spray when weeds are emerged. Repeat only after weeds reappear. See rates for Use one of the following products in 1e. The herbicides listed in 1e provide products in addition to a control of emerged weeds only. In herbicide listed in 1e: contrast, the products listed here have Refer to product no activity on emerged weeds, but PREEN or TREFLAN 5G labels for prevent the emergence of many () application rates of weeds for up to several months. These these herbicides. herbicides inhibit root development of SURFLAN AS germinating grasses and many (oryzalin) broadleaf weeds. They can be used safely around many woody and PENDULUM or PRE-M herbaceous plants in landscapes. ()

BARRICADE or FACTOR (prodiamine)

1 Trade names (in capital letters) are used for identification. No product endorsement is implied nor is discrimination intended against similar materials. See previous pages for additional product names. 2 Active ingredients are given in parentheses. 1 fluid ounce (fl. oz.) = 2 tablespoons (Tbsp.); 8 fl. oz. = 16 Tbsp. = 1 cup