Developed by Pringle Creek Watershed Council Salem, Oregon Urban Weed Management

Presentation overview Definition of “weeds” Weed impacts Ways to identify and control common invasive plants How to tackle weeds in your yard Resources for additional help

What is considered a weed? Any plant growing where it is not wanted. Invasive and noxious weeds are the most troublesome. –Rapidly dominate the site –Very difficult to control

Noxious Weeds in Oregon Landowners are responsible for controlling the spread of noxious weeds on their property Class A – worst; Class B – not as bad Class “A” Weeds Class “B” Weeds

Weed impacts Out-compete other plants for water, nutrients, and sun Costly and difficult to control Loss of wildlife and fish habitat; yard space Some are toxic to people and animals Decrease property value Increase erosion Can take over recreational areas Minimize land uses Spread rapidly

How do weeds spread? Humans Pets Wildlife Water Wind Vehicles Machinery “Wildflower” mixes We plant them Soil disturbance

Weed Management Buy clean seed for wildflowers or lawns; don’t plant weeds! Clean yard equipment before using it in another area Control weeds along streams Use mulch materials or weed mats Pull weeds early – before they go to seed! Prevention is the most effective practice of all!

Control Methods Mechanical Mowing, hand pulling, burning, solarizing Cultural Shading, site preparation, plant appropriate competitive vegetation Biological Parasites, predators, and pathogens; typically a slow process Chemical Often requires repeated application; can be sprayed, wiped or painted onto leaves or stumps; usually most effective in fall; USE ACCORDING TO LABEL

 Perennial  Woody evergreen vine  Reproduces by seed and roots  Can kill trees!  Berries are poisonous to most wildlife. Starlings love them! Control methods: hand pull or roll up vines cut stems on vines in trees & pull away lower vines from trunk apply herbicides (requires repeated application due to waxy leaves) English Ivy (Hedera helix)

 Perennial  Deciduous to partially evergreen  Reproduces by seed and roots  Doesn’t grow as well in shade Control: mow (at ground level) repeatedly dig or pull up root crowns deep shade from larger trees apply herbicides in the fall to leaves or cut stumps Himalayan Blackberry (Rubus discolor)

 Biennial  2-5 feet tall  Flowers purple July- September  Reproduces by seed  Seed can be viable for 10 years Bull Thistle (Cirsium vulgare) Control: hand pull cut or mow before going to seed apply herbicides in late fall or early spring

 Perennial  Flowers light pink-purple  Grows 1-4 feet tall  Has deep horizontal roots  Reproduces through creeping roots, some seed Canada Thistle (Cirsium arvense) Control: pull by hand (small plants) apply herbicides; spot-spraying young plants is very effective

 Perennial  Can grow up to 12 feet tall  Hollow, bamboo-like stems  Long creeping roots  Dies back in winter Control: Cut close to ground regularly (every 2 weeks during growing season)* dig (small plants and surface roots) apply herbicides to leaves & stems in the summer or early fall *be sure to properly dispose of all plant material Japanese Knotweed (Polygonum cuspidatum)

Control: hand pull or dig* (small plants) apply herbicides in early spring or late fall *be sure to wear gloves & properly dispose of all plant material  Biennial  Grows to 10 feet tall  Tiny white flowers & purple-mottled stems  All parts of plant are highly poisonous (if eaten)  Reproduces by seed Poison Hemlock (Conium maculatum)

Control: pull with weed wrenching tool mow or cut (prior to seed ripening) apply herbicides to foliage while actively growing or bark anytime  Perennial  Woody shrub with dark green branches, 3-10 feet tall  Reproduces by seed; seeds are protected by a flat pod  Soil disturbance results in a new crop of seedlings Scotch Broom (Cytisus scoparius)

 Perennial grass  Leaves ¼ - ¾ inches wide  Stems 2-7 feet tall, covered by waxy coating  Forms thick mat of roots and rhizomes Reed Canarygrass (Phalaris arundinacea) Control: hand pull or mow solarize shade out the plant apply herbicides in early spring or fall

Control: cut, dig, or hand pull (small plants) cut and remove the flowering spikes to prevent new seedlings apply herbicides when actively growing at full to late flowering  Perennial  Flowers purple on spikes  Stems are square; plant can be 6-8 feet in height  Reproduces by seed and roots Purple Loosestrife (Lythrum salicaria)

 Perennial  Grows up to 6 feet tall  White, pink, violet or blue flowers  Brought to the U.S. as an ornamental; widely planted Control: hand pull (seedlings) apply herbicide to cut stumps Note: cutting the plant encourages growth and applying herbicides to leaves is generally ineffective. Butterfly Bush (Buddleia davidii)

Weed treatment in riparian areas Select the most effective treatment methods for the site If herbicides are used, be sure the label allows application adjacent to or in the water Consider wipe application or hand removal

Now what? Inventory the plants on your property Identify invasive plants and weeds Do you have a weed problem? Why? What can you change about the way you manage your property to decrease the weed population? ENGLISH IVY

Proper disposal of weeds Put fresh noxious and perennial weed material in your garbage Don’t add it to your compost bin or yard debris cart; especially seeds or root material Don’t leave any root parts or seeds in wet areas; they will sprout!

Then... Determine appropriate controls and your plans for the site and start working Monitor for invasive plants Plant native plants in your yard after the weeds are under control Marion & Polk SWCDs have annual native plant sales in February Share this information with others

Helpful Resources Pringle Creek Watershed Council………… web: Marion Soil & Water Conservation District… web: Oregon Department of Agriculture………… web: OSU Extension - Marion County Office…… web: extension.oregonstate.edu/marion Pacific NW Weed Control Handbook web: weeds.ippc.orst.edu/pnw/weeds

Helpful Books Weeds of the West Western US Cooperative Extension Services Tom Whitson, Editor; 2001 Northwest Weeds Ronald J. Taylor; 2003 Plants of the Pacific Northwest Coast Jim Pojar and Andy Mackinnon; 1994 Handbook of Northwestern Plants Helen Gilkey and LaRea J. Dennis; 2001 Gardening with Native Plants of the Pacific Northwest Arthur Kruckeberg; 2003 Trees and Shrubs for Pacific Northwest Gardens John Grant, et. al.; 2003