Tillamook County Soil and Water Conservation District

Invasive Species

Invasive Species Management Program

What the District Does

  1. Identify unknown plants
  2. Assist the public with weed infestations by providing detailed treatment information
  3. Work with land owners to identify and eradicate new invasive species before they proliferate
  4. Deploy control measures to limit highly damaging weeds
  5. Ensure tansy ragwort, bull thistle and Canada thistle populations are being controlled to prevent their spread onto neighboring properties


Here is a list of Common Weeds of Tillamook County to get you started.

The Oregon Department of Agriculture website lists all the species which are considered invasive.


How a Plant Becomes a Problem

Invasive species are rarely made overnight. Many come from nurseries and are sold as ornamentals or ground covers. Over time they produce a large amount of seeds, each one having the potential to become a unique individual. As more and more seasons pass the probability one of these seeds will be particularly well suited to this new area increases. Once one of these well adapted plants emerges it can spread rapidly and out compete native plants which are well suited to the area. Native plants are at a disadvantage in this scenario because they have pests and pathogens which reduce their vigor and make it harder to compete with introduced plants which don’t have as many natural predators of diseases.


Prevent New Invasions

The more foreign plant material introduced into an area, the more likely a new weed will emerge. Many weedy plants can regrow from fragments and in compost. They must be burned or put in the garbage to prevent them from spreading. Planting species native to our area eliminates this risk. Native plants are also uniquely adapted to our climate and thus require less care than garden variety plants. Why mow every couple weeks when you can put down some native plants and be done with it. But wait! There’s more! Since they aren’t very commonly planted, they draw more interest than anything you can buy at the store.


Native Plants

Native plants are a great option for planting in almost any situation. They are uniquely adapted to our climate and require very little care once they become established. They have natural resistance to many of the plant diseases common in our area as an added bonus. They also provide many benefits to our native pollinators, birds and other wildlife.

Click here to see a list of local native plant nurseries.

Stopping The Spread

There are a variety of measures you can take against unwanted plants on your property. The best methods vary from plant to plant, which is why it is important to know which one you are dealing with before attempting to remove it. Small patches can usually be removed by carefully digging them out. Larger patches can be treated by removing the above ground vegetation,  covering it with cardboard and topping it off with some good soil. This should be replanted to discourage any rogue weeds that manage to poke trough. The final option for exceptionally challenging problems is responsible herbicide use.

Tillamook County SWCD is a partner of the online Oregon Invasive Species Hotline. Invasive weeds reported from Tillamook County to the hotline are referred to Tillamook County SWCD.  Other species sightings (such as animals or insects) are referred to other experts.  Hotline visitors can easily search for existing reports by clicking icons on a map, or typing more detailed searches into a search bar.  Photos can be added to reports made from your mobile phone. The Hotline is a partner with the Oregon iMapInvasives program, incorporating reports from Oregonians into a statewide invasive species dataset that is further shared with local, state, and national agencies. Both the Oregon Invasive Species Hotline and the Oregon iMapInvasives program are housed at Portland State University and the hotline is managed in partnership with the Western Invasives Network and the Oregon Invasive Species Council.


Have questions or concerns regarding weeds?

Contact Us

Troy Abercrombie,  Weed Program Coordinator
Tillamook County Soil & Water Conservation District
Office: 503-842-2848 Ext. 103
4000 Blimp Blvd., Suite 200,
Tillamook, OR 97141