Agriculture: Peppermint Pest Management Guidelines

Herbicide Treatment Table

Common name Amount per acre REI‡ PHI‡
(Example trade name) (hours) (days)
Not all registered pesticides are listed. The following are listed alphabetically. When choosing a pesticide, consider information relating to environmental impact, resistance management, the pesticide's properties, and application timing. Tank mixes may be necessary to achieve desired control; see Susceptibility of Weeds to Herbicide Control for information on specific weed control. Always read the label of the product being used.
 
PREPLANT
A. GLYPHOSATE
(Roundup, etc.) See label See label See label
WSSA MODE-OF-ACTION GROUP NUMBER1: 9
COMMENTS: Controls a wide variety of weeds, but is registered only for use before planting, not within 30 days of planting. It may be used after planting only as a spot treatment. Use 2% solutions of product and follow label directions regarding the use of surfactants. Add about 17 lb/100 gal of ammonium sulfate; mix with water before adding herbicide. Difficult-to-control weeds, such as volunteer garlic and field bindweed, will require two treatments. Improved field bindweed control has been noted when this material is applied early in the day.
 
B. PARAQUAT* 0.5–0.75 lb a.i.
(Gramoxone Inteon) 2 lb/gal 2–3 pt 12 NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Excellent on emerged winter annual weeds such as cheatgrass and shepherd's-purse. May be used on both baby and established mint but is poor on volunteer cereals, salsify, and filaree. Combining paraquat at low rates (1/2 label maximum or 0.38 lb a.i.) with low rates of oxyfluorfen (0.13–0.25 lb a.i.) enlarges the spectrum of weeds controlled and enhances weed control. Do not apply this combination to emerged mint because of the injury potential. Always use a surfactant (0.25% or 2 pt/100 gallons) and apply late in the evening for best results. Weeds that germinate after application will not be controlled.
 
POSTPLANT
A. BENTAZON 1–2 lb a.i.
(Basagran) 4EC 2–4 pt 48 NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 6
COMMENTS: Controls only broadleaf weeds and is the safest in baby mint. Always use high end of label rate; relatively expensive because of the higher rates required for effective control. Weak on mayweed chamomile. May be tank mixed with sethoxydim for control of both grass and broadleaf weeds. Use higher rates for larger weeds and weeds such as mayweed chamomile. May be used in newly established mint. Use a crop oil concentrate at the rate of 1 qt/acre with this product. Considered to be a ground water contaminant and requires a use permit within Ground Water Protection Areas. Works best with warmer temperatures.
 
B. BROMOXYNIL 0.25–0.5 lb a.i.
(Buctril) 2EC 1–2 pt 24 70
WSSA MODE-OF-ACTION GROUP NUMBER1: 6
COMMENTS: Labeled for established mint only. Do not use in spring-planted mint. Apply to dormant mint. Often causes injury to mint, particularly when temperatures are 70°F (or higher) on the day of application or within 5 days of application. Do not add surfactants because increased injury will result. Most effective with least crop damage when applied through automated sprinkler systems. Yields are typically not affected by injury caused at low application rates. Good for control of pigweed, lambsquarters, or sunflowers at young growth stages (less than 6 inches) and when ground application of other herbicides is not possible because of wet soils or dense growth of mint. Do not apply more than 6 pt/acre/season.
 
C. CLETHODIM 0.07–0.24 lb a.i.
(Select Max) 9–32 oz 24 21
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Can be used in baby mint and also in established mint for control of grasses. Applied to emerged grassy weeds where it is absorbed by the leaves. It does not have soil activity. Controls both annual and perennial grass weeds, including annual bluegrass. Use the high rate for heavy grass pressure, annual bluegrass, or when grass height exceeds the label recommendation. A crop oil concentrate must be added with this herbicide. Add about 17 lb/100 gal of ammonium sulfate; mix with water before adding crop oil concentrate and then herbicide.
 
D. CLOPYRALID 0.12–0.375 lb a.i.
(Stinger) 3EC 0.33–1 pt 12 45
WSSA MODE-OF-ACTION GROUP NUMBER1: 4
COMMENTS: Apply low rates when weeds are small because injury to mint can occur at high rates. Controls composite weeds such as salsify and legumes such as clover. Do not rotate to susceptible crops (strawberry, alfalfa, onions, potatoes, etc.) within 12 months of application. Do not apply more than one pint/acre/season. Do not add surfactant because it may reduce selectivity to mint and result in crop injury. Do not feed mint slugs to livestock or use mint slugs for compost in susceptible crops such as legumes.
 
E. DIURON 1.6–2.4 lb a.i.
(Drexel Diuron) 4L 1.6–2.4 qt 12 NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 7
COMMENTS: Labeled for established mint only, at least 1 year old. Apply only when mint is dormant. Use the low rate on sandy soils and the high rate on other soils. May be mixed with paraquat and oxyfluorfen. Do not plant susceptible crops within one year if applied rates exceed 1.5 lb a.i./acre. For use only in Del Norte, Humboldt, Lassen, Modoc, Shasta and Siskiyou counties in California under special permission from California Department of Pesticide Regulation. Considered to be a ground water contaminant and requires a use permit within Ground Water Protection Areas. Not all diuron formulations marketed in California have mint on the label.
 
F. FLUMIOXAZIN 2 oz a.i.
(Chateau SW) 4 oz 12 80
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: Provides burndown of emerged weeds as well as residual control. Effective against small winter annuals. Must be applied to dormant mint otherwise unacceptable injury may occur. May be applied anytime to dormant mint, but not after March 1. Apply in a minimum of 15 gallons per acre. May be tank mixed with paraquat for additional burndown activity. Add about 17 lb/100 gal of ammonium sulfate; mix with water before adding surfactant at 0.25% (2 pt/100 gal) and then herbicide. Use allowed under a supplemental label.
 
G. OXYFLUORFEN 0.13–1.75 lb a.i.
(Goal, GoalTender) Label rates 24 NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 14
COMMENTS: May only be used on dormant mint. Use higher rates (to 0.5 lb a.i.) on established mint. Apply only one application per season. Particularly effective for cheeseweed and filaree (Erodium spp.). Apply to weeds that are 4 inches or less in size. May be tank mixed with paraquat for improved contact weed control.
 
H. PARAQUAT* 0.33–0.5 lb a.i.
(Gramoxone Inteon) 1.3–2 pt 12 NA
WSSA MODE-OF-ACTION GROUP NUMBER1: 22
COMMENTS: Apply when crop is dormant and when weeds are less than 6 inches tall. Do not apply more than 0.75 lb a.i./acre/season. More effective weed control can be achieved by mixing with oxyfluorfen at low rates (0.13-0.26 lb a.i. of oxyfluorfen and 0.38 lb a.i. of paraquat). Always add a surfactant.
 
I. PENDIMETHALIN 0.7–1.9 lb a.i.
(Prowl H2O) 1.5–4 pt 24 90
WSSA MODE-OF-ACTION GROUP NUMBER1: 3
COMMENTS: Do not apply to first year mint. Do not exceed 4.0 pints/acre/season. Do not apply using an irrigation system. Do not feed treated mint hay to livestock or allow grazing of treated mint hay.
 
J. SETHOXYDIM 0.19–0.47 lb a.i.
(Poast) 1–2.5 pt 12 20
WSSA MODE-OF-ACTION GROUP NUMBER1: 1
COMMENTS: Only controls grassy weeds. Use high end of label rate. Applied to emerged grassy weeds where it is absorbed by the leaves. It will not control broadleaf weeds, bluegrass, or fine fescue. It may be used in either baby and/or established mint. The most common use of sethoxydim is to control grasses missed by residual herbicides. If residual herbicides are applied early in fall, their effectiveness is usually gone by late spring, and sethoxydim may be used to control summer grasses such as barnyardgrass (watergrass).
Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of the two intervals is the minimum time that should elapse before harvest.
* Permit required from county agricultural commissioner for purchase or use.
1 Group numbers are assigned by the Weed Science Society of America (WSSA) according to different modes of action. Although weeds may exhibit multiple resistance across many groups, mode-of-action numbers are useful in planning mixtures or rotations of herbicides with different modes of action.
NA Not applicable or not available.
Text Updated: 02/11