Managing Invasive Plants

Kickapoo Valley Reserve

June 11, 2011

John Exo, UW-Extension

John.exo@ces.uwex.edu

Outline

History of invasive establishment

Why species are invasive

Strategies

Some problem species

From John T. Curtis,

Vegetation of Wisconsin, 1959

Early Vegetation

Early Landscape

“Our waters filled with fish, and the air with game birds, and the rock ledges with rattlesnakes, and the woods with large game…We have no Canada thistles or mean men.”

Wm. H Canfield, 1842

Sauk County Surveyor

Invasive Beginnings

Wisconsin Historical Society

New People, New Pests

“Ever since the settlement of the country, there has been a tendency for certain plants and animals to get out of hand…Usually these runaways have been foreigners (like the carp, Norway rat…) but native species…are clearly also capable of pest behavior.”

Aldo Leopold, 1945

Definitions

“Invasive” definitions differ depending on the goal.

“…causes economic harm to….”

“interferes with land management goals…”

“kills or displaces populations of native species…”

What makes a plant invasive?

Tolerate wide range of soil, light, other conditions

Longer growing period

Alter soil chemistry

Prolific seed production

Few or no natural controls

What do we do?

Get educated: inventory, map, make a plan

Learn to ID and know plants’ biology

Create a plan

Learn & use control methods

Monitor & adapt

Take inventory

Aerial photo or scaled lot layout

Plant I.D. books/websites

Estimate species present & density

I.D. land use – past, present & future

Look beyond your property lines

Know thy enemy

Learn to identify the plants

Seedling

Adult

Dormancy

Learn plants’ biology

Annual

Biennial

Perennial

Know thy enemy

Annuals

Live one growing season as a plant

Survive through seed

If they don’t produce seed, they can’t reproduce

Annuals

Live one year, survive by seed

Giant, common ragweed

Foxtail grass

Know thy enemy

Biennials

Live TWO growing seasons

Survive through seed

Produce a lot of seed

Biennials

Live two years, survive by seed

Garlic mustard

Wild parsnip

Bull, musk, plumeless thistle

Sweet clover

Spotted knapweed

Biennials: Garlic mustard

WI DNR photos

Biennials:Wild Parsnip*(a monocarpic perennial)

Wild parsnip burns!

• Phyto-Photo-Dermatitis:

• Juice-skin-sunlight

• Blister scars can last years.

Biennials: Bull thistle

Know thy enemy

Perennials

Live many growing seasons

Survive through stored energy

Reproduce via seeds, suckers, roots

Important to know if:

Simple roots (honeysuckle)

Creeping roots (Can. thistle)

Perennial: Canada thistle

•Primary reproduction: creeping

horizontal lateral roots

•dense clonal growth

Perennial: Multiflora Rose(Rosa multiflora)

Identifying

characteristic:

bristles at base of

petiole

Multiflora Rose

Perennial: Common buckthorn

Unfair competition. . .

Perennials: Bush Honeysuckles

(Lonicera spp.)

Habitat: upland, especially under roost treesBlooms: May to June, produces orange or red berriesFlowers are white, yellow, orange, or pinkEarly spring leaf-out, late fall leaf drop

Perennials: Autumn olive

Habitat: dry uplandBlooms: May to JuneFlowers are white and fragrantReproduces mostly by root suckering

Autumn olive

Problem Ornamental Species

Japanese knotweed

Japanese barberry

buckthorns

Asian honeysuckles

Amur maple

Common tansy

Oriental, or Round-leaved bittersweet

Some watch list species

Japanese hedge parsley

Wild chervil

Hill’s mustard

Japanese knotweed

Teasels

Prioritization

Importance of habitat

Size of population

Rate of spread

interfere with land use?

Resources available

Management strategies

Monitor year-round, especially along trails, roads

Look beyond property lines

Prioritize species; areas

Timing is everything

Management methods

Ounce of prevention…

Pull

Cut/Mow

Girdle

Cut stem

Graze

Prescribed fire

Herbicide (foliar, basal bark)

Integrated methods are most successful

Prevention

Encourage competition

Proactively establish competition

Pull !!!!

Good for young people, small infestations, small plants.

Mow/Cut

Timing is critical—best when in flower.

Repeated mowings likely needed

Slows, but may not kill plants.

Can be combined with herbicide methods.

Mowing/Cutting Equipment

GirdleGood for clonal tree species

Labor intensive

Very effective if done correctly

Timing: June best

1 or 2 step method

Photo courtesy of Tom Brock

Girdling – Step 1 Girdling – Step 2

Cut-Stem Treatment

Good winter option

Very targeted use of herbicides

Photo: Savanna Oaks Foundation, Inc

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Basic Woody Shrub Cut-stem Control Method

Target: Small to medium invasive shrubs, e.g. buckthorn,

honeysuckle, Autumn olive, prickly ash, etc.

Herbicides:

systemic herbicide such as glyphosate (Roundup or generic) or Triclopyr (Garlon 4 or generic)

Basic Woody Shrub Cut-stem Control Method

Timing: Summer, Fall or Winter are preferred.

Avoid early spring and heavy snow periods.

Above-freezing temps when using water-soluble

herbicides such as glyphosate.

Apply water-soluble herbicides within minutes of cutting.

Triclopyr can be applied at any temp

Basic Woody Shrub Cut-stem Control Method

Technique: Cut stems at no higher than 6”

Work in pairs, if possible, to avoid “escapes”

Work in a pattern

Treat only outer edge

Photo courtesy: Tom Brock

Grazing

Timing

Palatability

Goats can be “trained” to

some species

Repeated treatments

necessary

Prescribed Fire

Photo courtesy of Tom Brock

Requires training

Experience

Specialized equipment

Good Public relations

Good neighbor relations

Timing!

Usually integrated with other methods

Using Fire for Management Requires: Special training

Specialized equipment

Good Public relations

Good neighbor relations

Experience

Timing!

Integrated with other methods

Foliar herbicide

Safety first

Timing is critical

better for larger infestations

Good in combination with mowing

Selective vs non-selective herbicides

Pre- vs post-emergence application

Basal bark herbicide

Small; smooth bark

Generally, single-stem shrubs & trees

Limited herbicide choices

Treat all clone stems

Photos courtesy of Tom Brock

Integrated Methods

Most successful control efforts involve an integrated approach that include monitoring & early detection.

Photo courtesy Tom Brock

Other Precautions

Clean shoes to prevent seed spread

Minimize soil disturbance

Consider wildlife & water role in spread

Monitor imported materials (gravel, mulch, etc)

Develop a management plan

•Garlic mustard presence shown.

•Goal is to …

Road

Garlic mustard biology

Biennial

Seedling/rosette yr 1

Flower, then die yr 2

Spread by seed only

Vehicles

Shoes

Animals

Water

Develop a management plan

Road

1. satellites: goal to eradicate

Combine methods to prevent

any seed production.

2. Patch along road: goal to

prevent spread.

Focus efforts on outer edges

and roadside

Example Plan

Satellite populations:

Pull 2nd year plants before flowering

Spray in 1st year plants in fall or very early spring

Example Plan

Large patch along road/trail

Mow, pull, spray along road before seed set.

Work perimeter inward

Spray rosettes fall/early spring

Pull escapes in between

Repeat, monitor, re-map ? years.

Calling All Volunteers!

Kickapoo Valley Woods Cooperative

The Prairie Enthusiasts

The Nature Conservancy

Kickapoo Valley Reserve?

Other Resources

Membership, links, and information

http://www.ipaw.org

Summary

Invasives are already here

Early detection & prevention are critical

Introduction of new species mostly dependent on our behavior

Set realistic goals

Make a plan, then adapt

Questions?