Invasive Species 101: A Primer for Gardeners Robert Emanuel, Ph.D.Water Resources and Community Development Faculty, Tillamook and Clatsop counties
IntroductionWhat are invasive species?Why should we care?Biology & managementSome common invadersWhat can gardeners do about them?Resources for more information.
Invasive species means an alien specieswhose introduction does or is likely tocause economic or environmental harmor harm to human health.
Biological invaders destroy habitats or out‐compete native plants and animals. Why should we care?Invasive species costs Americans about $143 billion/year! At least 30 new potential biological invaders enter the US every day…
Definitions: Invasive Plants “Weed” Exotics A plant (non‐native) growing where you do Lots of beneficial not want it.species: Crops, pasture, forestry “Noxious”& ornamentals. A regulatory designation. “Invasive” Spreads outside of Natives cultivation, and Co‐evolution causes human, with other environmental, species, our economic harm. natural heritage
What makes a plant invasive?Lack normal environmental constraintsFast growth and reproductionHighly adaptable a wide range of conditionsOften can transform their environmentPromoted by new or existing disturbancesLess biodiversity in the native ecosystemSometimes work with other invasive species
Key Stages in Plant Invasions New Range Limits? Escape Adaptation? Lag Time Invasion IntroductionArea Infested Time
What can gardeners do?Know the enemy & teach others about themGrow native & non‐invasive wherever possibleHelp others to do the sameHelp the public with information on treatmentMonitor and report new invadersCheck clothes, vehicles, pets when out & about
What can gardeners do?Don’t share unless you know it’s not invasiveCheck seed mixes before you buy themStay away from generic wildflower mixturesWatch for hitchhikers in nursery stockUse weed‐free soil and mulchWatch introductions for aggressive behaviorDon’t dump your yard clippings in the wild!
If you have a known invasive (but can’t part with it)Deadhead faithfullyUse root barriersDispose of plant material properly—bagged in the garbage or burned (completely)Please don’t share your invader with others! Contain it, control it, or cage it!
For Water GardenersAlways wash new introductions (think snails)Keep water garden separate from native watersNever dump water garden materials or water into native watersResearch your plants for invasive potential—many commonly used aquatics are!
Robert M. Emanuel, Ph.D.Water Resources & Community DevelopmentTillamook & Clatsop counties2204 Fourth StreetTillamook, OR 97141(503) 842‐5708 X 2 email@example.com/h2onc