NC State Extension Publications

 

A quick guide providing commonly used herbicides used in forest site preparation and release treatments. Tables are broken into (1) conifer site preparation, (2) hardwood plantation site preparation, (3) hardwood natural regeneration site preparation, (4) conifer early release, (5) early hardwood release, (6) cut surface herbicides used for intermediate or crop tree release.

Each table provides the herbicide active ingredient, trade names of labels approved for forestry applications, best time of year to use the herbicide, target species, and species that are resistant to the herbicide. The trade names are linked to the most recent specimen label so users may look up the details of that brand for safety, mixing, and delivery methods. The links use the CDMS database for specimen labels.

Common Herbicides for Conifer Site Preparation

Active Ingredient Herbicide Trade Name(s) and Links to Specimen Labels
Use to get details of delivery, mix rates, and safety requirements
Time of Year Target Resistant

Imazapyr

Arsenal AC, Polaris AC

Summer, in advance of regeneration

Most hardwoods, annual and perennial grasses and forbs, Bermuda, fescue, crabgrass, dog fennel, pigweed, greenbriar, morning glory

Elms, woody legumes, wax myrtle, croton spp., rubus, buckeye, baccharis, pine

Imazapyr

Chopper, Polaris SP (surfactant)

Growing season following full leaf expansion

Most hardwoods, annual and perennial grasses and forbs, Bermuda, fescue, crabgrass, dog fennel, pigweed, greenbriar, morning glory

Elms, woody legumes, wax myrtle, croton spp., rubus, buckeye, baccharis, hickory, pine

Glyphosate

Accord XRT II, Razor and Razor Pro, Rodeo, Roundup Pro Conc

Prior to planting, active growth following full leaf expansion

Most hardwoods (black locust, persimmon, sassafras, sumac, sweetgum, yellow-poplar) most annual and perennial grasses and forbs

Red maple*, oaks*, ash*, hickory*, dogwood*, rubus, greenbriar, Virginia creeper, trumpet vine

Glyphosate and Imazapyr

Prep-It

During periods of active growth

Control most annual and perennial grasses, broadleaf weeds, vines, and woody vegetation

Metsulfuron Methyl

Escort XP, Patriot

During periods of active growth following full leaf expansion

Wide range of annual and perennial broadleaf weeds and woody plants, kudzu, multiflora rose

Grasses, yellow poplar, loblolly pine

Sulfometuron Methyl

Oust XP, Spyder

Early spring, before herbaceous weeds emerge or shortly thereafter

Annual grasses and forbs and certain perennial herbs

Bermuda, broomsedge, croton spp., trumper vine, panicums, pines, most hardwoods

Sulfometuron Methyl and Metsulfuron Methyl

Oust Extra

After full leaf expansion in spring and before normal defoliation in fall. Herbaceous weeds: apply pre-emergence or shortly thereafter

Various woody plants, vines and herbaceous weeds

Loblolly pine

Triclopyr

Element 3A, Garlon 3A, Tahoe 3A, Element 4, Garlon 4 Ultra, Tahoe 4E, Forestry Garlon XRT

During periods of active growth

Most hardwoods, southern pine, waxy species such as bay, gallberry, wax myrtle, and yaupon, forbs, dog fennel, pigweed, greenbriar, and morning glory, rubus

Grasses

Aminopyralid

Milestone

Anytime during the growing season. Preferred when weeds are small and actively growing

Rubus, morning glory; horseweed, pigweed, sicklepod, ragweed, wilding pines

Grasses

Clopyralid

Clean Slate, Transline

Anytime during the growing season. Preferred when weeds are small and actively growing

certain broadleaf weeds including thistle, kudzu, sicklepod, morning glory, ragweed, coffee weed most legume species

Most established grasses and woody plants

Dicamba

Vanquish

During periods of active growth

Many annual and perennial broadleaf weeds, woody brush (including hardwoods and pines), multiflora rose (when dormant)

Fosamine

Krenite S

Apply during the growing season

Postharvest control of pine and hardwood species for southern pine planting site preparation

Non-woody plants (usually) and waxy leafed species

Hexazinone

Velpar DF (dispersible granules), Velossa, Velpar L (liquid)

Early spring - early summer after bud break and before hardening off

Most hardwoods, rubus, crabgrass, fescue, lespadeza, horseweed, dog fennel, annual and perennial rye grass

Yellow-poplar, eastern redcedar, sassafras, blackgum, hollies, American beautyberry, Bermudagrass, white snakeroot, broomsedge, Johnsongrass, sicklepod, trumpet vine, morning glory

Picloram

Tordon K,

Trooper 22K

(Restricted Use)

During periods of active growth

Annual and perennial broadleaf weeds, woody plants especially legumes and southern pine speciesand vines

Most grasses are resistant

Picloram and 2, 4-D

Tordon 101 M (Restricted Use)

During periods of active growth

Most annual and perennial broadleaf weeds, woody plants, and vines

Most grasses are resistant

Common Herbicides for Hardwood Plantation Site Preparation

Active Ingredient

Herbicide Trade Name(s) and Links to Specimen Labels

Use to get details of delivery, mix rates, and safety requirements

Time of Year

Target

Resistant

Clopyralid

Clean Slate, Transline

Anytime during the growing season. Preferred when weeds are small and actively growing

certain broadleaf weeds including thistle, kudzu, sicklepod, morning glory, ragweed, coffee weed most legume species

Most established grasses and woody plants

Glyphosate

Accord XRT II, Razor and Razor Pro, Rodeo, Roundup Pro Conc

Prior to planting, active growth following full leaf expansion

Most hardwoods (black locust, persimmon, sassafras, sumac, sweetgum, yellow-poplar) and southern pine, most annual and perennial grasses and forbs

Metsulfuron Methyl

Escort XP, Patriot

During periods of active growth following full leaf expansion

Wide range of annual and perennial broadleaf weeds and woody plants, kudzu, multiflora rose

Most grasses, yellow poplar

Sulfometuron Methyl

Oust XP, Spyder

Early spring, before herbaceous weeds emerge or shortly thereafter. Can also be applied in fall prior to planting.

Annual grasses and forbs and certain perennial herbs

Bermuda, broomsedge, croton spp., trumper vine, panicums

Common Herbicides for Natural Hardwood Regeneration Site Preparation

Active Ingredient

Herbicide Trade Name(s) and Links to Specimen Labels

Use to get details of delivery, mix rates, and safety requirements

Time of Year

Target

Resistant

Glyphosate

Accord XRT II, Foresters, Rodeo

Growing season following full leaf expansion. Broadcast foliar or spray to wet foliage (but not to point of runoff).

Most hardwoods (black locust, persimmon, sassafras, sumac, sweetgum, yellow-poplar), southern pine, most annual and perennial grasses and forbs

Sulfometuron Methyl

Oust XP

Growing season during active herbaceous weed growth. Broadcast foliar application following shelterwood seed cut.

Annual grasses and forbs and certain perennial herbs

Bermuda, broomsedge, croton spp., trumper vine, panicums

Glyphosate and Sulfometuron Methyl

Rodeo and Oust XP

Mid summer to early fall. Broadcast foliar application following shelterwood seed cut.

Wide range of annual and perennial broadleaf weeds and woody plants, kudzu, multiflora rose

Common Herbicides for Early Conifer Release

Active Ingredient

Herbicide Trade Name(s) and Links to Specimen Labels

Use to get details of delivery, mix rates, and safety requirements

Time of Year

Target

Resistant

Imazapyr

Arsenal AC, Polaris AC

Late in second growing season following planting. Broadcast foliar application or directed foliar.

Most hardwoods, annual and perennial grasses and forbs, Bermuda, fescue, crabgrass, dog fennel, pigweed, greenbriar, morning glory

Elms, woody legumes, wax myrtle, croton spp., rubus, buckeye, baccharis, hickory, pine

Imazapyr

Chopper, Polaris SP (surfactant)

Late in growing season after formation of final conifer resting bud. Directed foliar spray applications.

Most hardwoods, annual and perennial grasses and forbs, Bermuda, fescue, crabgrass, dog fennel, pigweed, greenbriar, morning glory

Elms, woody legumes, wax myrtle, croton spp., rubus, buckeye, baccharis, hickory, pine

Glyphosate

Razor, Rodeo, Roundup Pro Conc

Later summer or early fall, after formation of final conifer resting bud. Broadcast foliar application.

Most hardwoods (black locust, persimmon, sassafras, sumac, sweetgum, yellow-poplar), most annual and perennial grasses and forbs

Metsulfuron Methyl

Escort XP, Patriot

Active growth following full leaf expansion. Herbaceous weeds: apply pre-emergence or shortly thereafter. Broadcast foliar application.

Wide range of annual and perennial broadleaf weeds and woody plants, kudzu, multiflora rose

Grasses, yellow poplar

Sulfometuron Methyl

Oust XP, Spyder

Dormant season prior to conifer bud break. Broadcast foliar spray for herbaceous weed control.

Annual grasses and forbs and certain perennial herbs

Bermuda, broomsedge, croton spp., trumper vine, Johnsongrass, panicums

Sulfometuron Methyl and Metsulfuron Methyl

Oust Extra

Active growth following full leaf expansion. Herbaceous weeds: apply pre-emergence or shortly thereafter. Broadcast foliar spray, loblolly pine only.

Various woody plants, vines and herbaceous weeds

Conifers somewhat

Triclopyr

Element 3A, Garlon 3A, Tahoe 3A, Element 4, Garlon 4 Ultra, Tahoe 4E, Forestry Garlon XRT

During periods of active growth. Directed spray application only.

Most hardwoods, vines, and broadleaf weeds such as dog fennel, pigweed, greenbriar, morning glory

Aminopyralid

Milestone

Spring to late summer: broadcast foliar overtop only on longleaf. Do not use over the top of loblolly or slash pine Directed, spot treatment only.

Broadleaf weeds such as Rubus, morning glory; vetch, horseweed, pigweed, sicklepod, ragweed, and wilding pine suppression

Young longleaf pine

Clopyralid

Clean Slate, Transline

Mid to late summer, after conifers have hardened off. Broadcast foliar application made over the top of tolerant tree species or directed spray to wet spot applications for broadleaf weed control.

certain broadleaf weeds including thistle, sicklepod, morning glory, ragweed, coffeeweed, wisteria and kudzuMany legume species

Grasses and many woody plants

Hexazinone

Velpar DF (dispersible granules), Velossa, Velpar L (liquid)

Spring after bud break and before full leaf expansion. Broadcast foliar application.

Most hardwoods, rubus, crabgrass, fescue, lespadeza, horseweed, dog fennel, annual and perennial rye grass

Grasses, yellow-poplar, eastern redcedar, sassafras, blackgum, hollies, American beautyberry, Bermudagrass, white snakeroot, broomsedge, Johnsongrass, sicklepod, trumpet vine, morning glory

Common Herbicides for Early Hardwood Release

Active Ingredient

Herbicide Trade Name(s) and Links to Specimen Labels

Use to get details of delivery, mix rates, and safety requirements

Time of Year

Target

Resistant

Clopyralid

Clean Slate, Transline

Anytime during the growing season. Preferred when weeds are small and actively growing. Broadcast foliar application made over the top of tolerant tree species or directed wet spot applications

many broadleaf weeds such as sicklepod, morning glory, ragweed, coffeeweed, thistle, wisteria, and kudzu

Grasses and most hardwood species

Glyphosate

Rodeo, Refuge

Summer, during periods of active growth, after full leaf expansion and before fall color. Directed spot treatments only avoiding contact with desirable species or broadcast during dormant period when hardwood crop trees are dormant. Only certain adjuvants recommended.

Most hardwoods (black locust, persimmon, sassafras, sumac, sweetgum, yellow-poplar) most annual and perennial grasses and forbs

Hexazinone (yellow poplar only)

Velossa, Velpar L

Early spring, after soil has settled around planting slit and before but break. Broadcast foliar application over top of planted seedlings

Most hardwoods, rubus, crabgrass, fescue, lespadeza, horseweed, dog fennel, annual and perennial rye grass

Grasses, yellow-poplar, eastern redcedar, sassafras, blackgum, hollies, American beauty berry, Bermuda grass, white snakeroot, broomsedge, Johnsongrass, sicklepod, trumpet vine, morning glory

Metsulfuron Methyl (yellow poplar only)

Escort XP, Patriot

Early spring, after soil has settled around root system and prior to bud break. Herbaceous weeds: apply pre-emergence or shortly thereafter. Broadcast foliar application over top of yellow poplar seedlings only.

Wide range of annual and perennial broadleaf weeds and woody plants, kudzu, multiflora rose

Grasses, yellow poplar

Sulfometuron Methyl

Oust XP, Spyder

Early spring, after soil has settled around planting slit and before bud swell stage. Broadcast foliar application over top of planted seedlings

Annual grasses and forbs and certain perennial herbs

Bermuda, broomsedge, croton spp., trumper vine, Johnsongrass, panicums

Common Herbicides for Cut Surface Methods Used in Intermediate or Crop Tree Release

Active Ingredient

Herbicide Trade Name(s) and Links to Specimen Labels

Use to get details of delivery, mix rates, and safety requirements

Time of Year

Target

Resistant

Aminopyralid and Triclopyr

Capstone

Any season except during spring sap flow. Injection or hatchet frill girdle and spray bottle

Most woody species

Imazapyr

Arsenal AC, Polaris AC

Any season, except during heavy sap flow in spring. Injection or hatchet frill girdle and spray bottle. Non-target injury could result through root grafting.

Many hardwoods

Elms, woody legumes, hickory, pine

Glyphosate

Accord XRT II, Razor and Razor Pro, Rodeo, Roundup Pro Conc

During active growth after full leaf expansion. Injection or hatchet frill girdle and spray bottle.

Most woody species including oak, poplar, sweet gum, sycamore; pine

Red maple, hickory, dogwood, black gum

Triclopyr

Element 3A, Garlon 3A, Tahoe 3A

Any season, except during heavy sap flow in spring. Injection or hatchet frill girdle and spray bottle. Non-target injury could result through root grafting.

Most woody species

Clopyralid

Clean Slate, Transline

Periods of active growth. Injection or axe frill girdle and spray bottle. Non-target injury could result through root grafting.

Woody legumes

Most hardwoods, pine

Dicamba

Vanquish

Any season, except during heavy sap flow in spring. Injection or hatchet frill girdle and spray bottle.

Many hardwoods and pines

Sweetgum, oak, maple

Hexazinone

Velossa, Velpar L

Summer. Injector or Hypo-Hatchet. Non-target injury could result through root grafting.

Most hardwoods

Yellow-poplar, eastern redcedar, sassafras, blackgum, hollies, pines, sourwood, dogwood, red maple

Picloram and 2,4-D

Pathway (Restricted Use)

Any season, except during heavy sap flow in spring or during periods of drought. Injector or hatchet frill girdle and spray bottle. Non-target injury could result through root grafting.

Most woody plants, and vines

Authors

Area Specialized Agent, Forestry
Harnett County
Extension Forestry Specialist
Forestry & Environmental Resources
Extension Associate
Forestry & Environmental Resources

Publication date: July 14, 2016

Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. A&T State University nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your local N.C. Cooperative Extension county center.

North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status or disability. In addition, the two Universities welcome all persons without regard to sexual orientation.