1. Kentucky’s Top 10 Worst Plant Threats

2. Chemical Control of Plants
What is needed:
Carrier (water or oil)
Herbicide
Surfactants (optional)

3. Types of Herbicides Glyphosate Inhibits aromatic amino acid synthesis
Brands
Accord (DowAgro)
Roundup (Monsanto)
not registered for forestry)
Rodeo (Monsanto)
aquatic label
Various generics

4. Types of Herbicides Imazapyr Inhibits branched amino acid synthesis
Does not kill conifers
Release pine from hardwoods
Brands
Arsenal AC (BASF)
Amine formulation
Chopper (BASF)
Ester formulation

5. Types of Herbicides Triclopyr Behaves like auxin (IAA)
Over stimulates cell metabolism
Brands
Garlon 4 (DowAgro)
Ester formulation for foliar and basal bark applications
Effective on actively growing brush by penetrating the bark and entering the cambium layer. Also effective as a late-season application
Garlon 3A (DowAgro)
Amine formulation for foliar, cut surface and tree injection applications.
Foliar applications are most effective during the period of active growth.
Tree injections and cut surface treatments can be applied year-round.

6. Types of Herbicides Hexazinone (DuPont)
Soil-active herbicide controls trees, brush, weeds, and grasses by inhibiting photosynthesis
Brands
Velpar L – Liquid
Velpar ULW – Granule
Oustar (+ sulfometuron) – Soluble granules

7. Types of Herbicides Metsulfuron (DuPont) Escort XP
Dispersible granule, postemergent herbicide
Mixes in water for spray application and controls many annual and perennial weeds and woody plants in non-crop areas and conifer plantations.
Best results are generally obtained when applied to foliage after emergence or dormancy break because
Escort XP is absorbed primarily through the foliage of plants and by the roots to a lesser degree.

8. Types of Herbicides Sulfometuron - DuPont Oust XP
Oust Extra is a dispersible granule herbicide that is mixed in water and applied as a spray or impregnated on dry, bulk fertilizer.
When applied as a spray, it is absorbed by both the roots and foliage of plants, rapidly inhibiting the growth of susceptible weeds.
When applied on dry fertilizer, Oust Extra is absorbed primarily by the roots.
For best results, apply before or during the early stages of weed growth before weeds develop an established root system.

9. Types of Herbicides Clopyralid Transline (DowAgro)
For selective, postemergence control of broadleaf weeds
Effective only on composites and legume

10. Types of Herbicides Picloram Tordon (Dow-Agro) Pathway RTU (Dow-Agro)
Ready-to-use herbicide is effective in cut surface applications
Premixed with dye
Use undiluted with tree injectors or in the frill girdle treatment using an axe.
Active ingredients are 5.4% picloram and 20.9% 2, 4 D-Amine.

11. Amur Honeysuckle
Amur honeysuckle (Lonicera maackii) is a tardily deciduous, upright, arching shrub to small tree.
Forms dense thickets in open forests, forest edges, old fields, and roadsides
Forms a dense shrub layer that crowds out native plants and regeneration
Depletes soil moisture and nutrients
Berries do not provide the fat and nutrient rich food that native species provide
Especially needed by birds for long flights

12. Amur Honeysuckle
Identified by arching habit, opposite branching and dark green leaves, red to orange glossy berries paired in leaf axils
Bark flaky and older branches hollow (native honeysuckles are solid)
States reporting infestations

13. Amur Honeysuckle
Hand pulling or mechanical removal can be used on small plants or light infestations
For seedlings and small plants; systematic herbicide like glyphosate at 2% solution can be applied to the foliage by spray or sponge
Well established stands should be cut and the stump sprayed or painted with a 20% solution of glyphosate.
Prescribed burning can be useful in open habitats.
Treatment should be used before seed dispersal (late summer, early autumn) to prevent reinvasion.

14. Kudzu
Kudzu (Pueraria montana) is a twining, trailing, mat-forming, ropelike, woody leguminous vine.
Occurs in old infestations, along right-of-ways, and stream banks
Forms dense mats over the ground, debris, shrubs, and mature trees.
Little spread by seed, usually spreads slowly by runners
Completely covers, kills by denying light penetration, and replaces existing vegetation.

15. Kudzu
Identified by alternate, pinnately compound, three-leaflet leaves
Stems yellow green with dense, erect golden hairs, aging to ropelike, gray, and hairless
Flowers lavender to wine-colored with yellow centers
Flattened, tan, fuzzy, legume seed pods
The most severe infestations occur in the piedmont regions of Alabama, Mississippi, and Georgia.

16. Kudzu Very difficult to control
Estimated cost up to $200 per acre for 5 years
Thoroughly wet all leaves the 3% solution of Tordon 101 or 2% Tordon K
July to October for successive years when regrowth appears
Spray climbing vines as high as possible or cut those that cannot be controlled
Prescribed burning in the spring can clear debris, sever climbing vines, and reveal hazards, making summer applications easier.

17. Winged Burning Bush (Euonymus alata)
Imported from Asia as a ornamental shrub
Shade tolerant, spreads by root suckers and animal dispersed seeds
Widely planted as an ornamental and along highways
Threatens forests, prairies, and coastal scrublands where it can form dense thickets and displace native woody and herbaceous vegetation.

18. Winged Burning Bush
Multiple stemmed and many branched, bushy shrub to 12 feet in height
Opposite leaves, dark green above, light green beneath
Fall color bright red
Four corky wings along young lime green branches
Seeds dangling pair or single reddish capsules in leaf axil, splitting in fall to reveal orange flesh covered seed.
Found throughout much of the northeastern United States

19. Winged Burning Bush
Thoroughly wet all leaves with Arsenal AC or Vanquish as a 1% solution
Stems too tall for foliar spray
Apply garlon 4 as 20% solution in basal oil, diesel fuel, or kerosene with a penetrant as basal spray on young bark
Cut large stems and treat stumps with 10% solution of Arsenal AC or 20% solution glyphosate herbicide
Seedlings can be pulled by hand in small infestations

20. Garlic Mustard (Alliaria petiolata)
Introduced from europe in the 1800’s for culinary and medicinal uses
Doesn’t require disturbance to enter forested areas, shade tolerant
Grows quickly in early spring and late fall, when other species are often dormant
Obligate biennial, first year seedling “rosette stage” stays green through winter
Not valuable for animal browse
Overruns and eliminates many native plants and wildflowers, also allelopathic

21. Garlic Mustard
Forb with one to several erect, light green stems from the same rootstock
Hairless above and hairy below
Basal rosette of kidney-shaped leaves (1st year), alternate heart-shaped to triangular leaves (2nd year)
Garlic odor when crushed
Terminal clusters of small white flowers
States reporting garlic mustard infestation
2nd year
1st year

22. Garlic Mustard
Both generations can be controlled by thoroughly wetting all leaves with a 2% glyphosate herbicide solution.
Include surfactant only if plants are not near surface waters
When herbicides cannot be used
Hand pull plants before seed formation
Repeated annual prescribed burns in fall or early spring
Burning individual plants with propane torches has shown some success

23. Multiflora Rose (Rosa multiflora)
Introduced from Asia as ornamental, live-stock containment, wildlife habitat, and living fences
Widely planted and spreads along right-of-ways, road sides, old fields, and forest margins, sometimes climbing trees
Colonize by prolific root sprouting, stems that root, and animal dispersed seed
Extremely prolific and forms impenetrable thickets that exclude native plant species

24. Multiflora Rose Erect climbing, arching, or trailing shrub
Stems long arching or climbing, recurved thorns
Leaves alternate, pinnately compound with 3 to 9 leaflets
Leafstalk often bristled with toothed hairs
Flowers white with 5 petals
States reporting infestation

25. Multiflora Rose
Cutting or mowing 3 to 6 times per growing season for 2 to 4 years is effective
Wet leaves with a 1% solution of Arsenal AC (April to June) or use an Escort-water mixture at 1 ounce herbicide per acre (April to October).
4% glyphosate solution from May to October is less effective but has no soil activity to damage surrounding plants
Stems too tall for foliar spray
Apply garlon 4 20% solution in basal oil, diesel fuel, or kerosene to young bark as basal spray
Cut stems and treat stumps with Arsenal AC as 10% solution or glyphosate as 20%

26. Oriental Bittersweet (Celastrus orbiculatus)
Introduced from Asia as a showy, ornamental vine
Shade tolerant but most infestations located in forest openings, margins, roadsides, and fields
Colonizes by aggressive vine growth, bird and animal dispersed seeds
Shades, suppresses, and kills native vegetation
Vines seriously damage vegetation by constricting and girdling stems
Threat to the native and rare American bittersweet (Celastrus scandens) due to hybridization and genetic identity loss

27. Oriental Bittersweet
Deciduous, twining, and climbing vine to 60 feet in tree crowns
Stems olive drab with raised, whitish, corky dots becoming tan to gray
Leaves alternate and variable, bluntly toothed
Dark green becoming bright yellow in late summer to fall
Conspicuous fruit; yellow orange to tan, splitting in winter to reveal fleshy scarlet inner sections, persistent through winter
American bittersweet has only terminal flowers and fruit
States reporting

28. Oriental Bittersweet
Juvenile plants or those in sensitive areas can be hand or mechanically pulled
From July to October wet leaves with a 3% mix of Garlon 4, Garlon 3A, or glyphosate.
For stems too tall:
Garlon 4 as 20% solution in basal oil, diesel fuel, or kerosene to lower 16 inches of stems
Cut stems and treat cut surfaces with Garlon 4 or glyphosate as a 25% solution

29. Japanese Knotweed (Fallopia japonica)
Introduced from Asia in the 1800’s
Invades high light, disturbed areas
Roadsides, ditches, wetlands, right-of-ways, streambanks, etc.
Associated with soil disturbances
Rarely found in low light areas such as forest understories
Dense patches emerge early in the growing season, crowding out native plants
Infestations near stream banks increase susceptibility to erosion
Of little value to wildlife
Seeds wind and water dispersed

30. Japanese Knotweed Dense growing, semi-woody shrub to 10 feet
Hollow, simply branched stems are smooth and shiny with enlarged nodes
Leaves are alternate and variable, usually triangle shaped with pointed tip and rounded base
Flowers greenish-white and minute, seeds small dry achene
Recognized by extremely dense growth form, often monocultural thickets
Above ground portions die back in winter
Particularly abundant in the eastern U.S. and coastal Washington and Oregon

31. Japanese Knotweed
Treat foliage with herbicides in mixture with water and surfactant
2% solution Garlon 4, Garlon 3A, or glyphosate herbicide
Ideal time to spray when surrounding vegetation has become dormant (Oct. to Nov.) to avoid damage to non-target species
If mixed with non-target plants, cut stems 5 cm above ground and treat with 25% solution of above herbicides
Subsequent foliar applications may be necessary to control new seedlings and resprouts

32. Purple Loosestrife (Lythrum salicaria)
Perennial herb introduced from Europe and Asia
Invades natural and disturbed wetland habitats; wet meadows, marshes, stream and river banks, pond margins, reservoirs, and ditches
Forms dense homogenous stands
Restricts native plants, including species of endangered orchids
Crowds out valuable native wildlife food plants, reduces habitat for waterfowl
Decompose quickly in the fall, causing nutrient flush and alteration of wetland function
Reproduces through high volumes of seed and vegetatively through underground stems

33. Purple Loosestrife
According to U.S. Fish and Wildlife, occurs in every state except for Florida
Tall (4 to 10 feet), erect herb with opposite or whorled leaves
Usually covered with a downy pubescence
Showy display of magenta-colored flower spikes throughout much of the summer
30 to 50 stems from a single rootstock

34. Purple Loosestrife
Small infestations may be pulled by hand, preferably before seed set
For older plants spot treatment with glyphosate based herbicide (Roundup for uplands, Rodeo for wetlands)
Biological control likely candidate for control of large infestations
3 species of insect from Europe have been approved for use by the U.S. department of Agriculture
Root-mining weevil (Hylobius transversovittatus), and two leaf-feeding beetles (Galerucella calmariensis and Galerucella pusilla)
Occasionally feed on native vegetation, but impact on non-target species is considered low
Hylobius transversovittatus
and rootstock damage

35. Chinese Silvergrass (Miscanthus sinensis)
Ornamental perennial grass introduced from eastern Asia
Infests roadsides, forest margins, and adjacent disturbed sites, especially after burning
Shade tolerant
Highly flammable and fire hazard
Crowds out native plant species
Seed viability spotty, new cultivars assumed to be mostly sterile

36. Chinese Silvergrass Tall, densely bunched, 5 to 10 feet in height
Many loosely plumed panicles in late summer, turning silvery to pinkish in fall
Dried grass standing with some seed heads during winter
Blades green to variegated with whitish collars
Tufted hairs at throat, sheath margins, and ligule, but otherwise hairless
States with suspected infestations

37. Chinese Silvergrass
Thoroughly wet all leaves with herbicides in water with a surfactant
Arsenal AC as a 1% solution
Glyphosate based herbicide as a 4% solution if non-target plants are an issue
September or October with multiple applications to regrowth
Manual removal before silvergrass goes to seed can be effective if repeated

38. Japanese Stilt Grass (Microstegium vimineum)
Introduced from Asia, sometimes called Nepalese browntop
Flourishes on alluvial floodplains and streamsides, colonizes flood scoured banks, forest edges, roadsides, damp fields, swamps, lawns, and ditches
Very shade tolerant
Prolific seeder, remain viable in soil up to 5 years, spreads by hitchhiking on shoes and clothing
Little wildlife food value
Replaces valuable native food sources
Wildlife continue to feed on native species while avoiding stilt grass, helping it colonize

39. Japanese Stilt Grass Sprawling annual grass
Flat short leaf blades with off-center veins
Stem branching near the base and rooting at nodes to form dense infestations
Throat collar hairy, ligule membranous with hairy margin
Dried whitish-tan grass remains standing in winter
States reporting infestations

40. Japanese Stilt Grass
Manual removal results in disturbed soils and aids germination of more stilt grass
Mowing or pulling just before seed set can prevent seed buildup
Herbicides can be used on resulting seedlings
Apply glyphosate as a 2% solution in late summer
Apply Vantage (see label) for situations that require more selective control and less impact on non-target plants