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Pesky Plant Trackers

Project background

Pesky Plant Trackers logoWe are seeking observers to report initial growth, flowering, and fruiting of three non-native invasive species in the Midwest and Northeast - wild parsnip, Japanese knotweed, and Bohemian knotweed.

Wild parsnip, a carrot-like perennial that can reach 6 feet tall, poses human health risk due to a phototoxin produced by the leaves. Skin contact with the leaves followed by exposure to sunlight will cause severe blistering. Parsnip can be managed by mowing, but only prior to mature seed development to prevent spread, or herbicide application during specific stages of plant growth. Mowing too late can help to spread seeds.

Japanese knotweed and Bohemian knotweed are aggressive, bamboo-like shoots that can reproduce without seed. Control is extremely difficult, but applying herbicides at certain stages of knotweed development can maximize their effectiveness and stop infestation.

Your observations as part of this campaign will enable land managers to correctly time management activities aimed at controlling these species. Researchers will use the phenology data you collect to understand relationships between accumulated temperature and life cycle events like initial growth and flowering. The researchers will then build models that use forecasted weather to predict the timing of these life cycle events.

2020 is the pilot year of a potentially larger effort to observe additional species in other regions of the country next year.

See results of this campaign from 2021.

Join us!

You can contribute by reporting observations of wild parsnip, Japanese knotweed, and Bohemian knotweed during the spring, summer, and fall. 

We invite you to take the Pesky Plant Trackers online training course for an in-depth tutorial on how to make observations on Japanese knotweed and wild parsnip. This course was designed by Abbie Anderson, Program Coordinator for Pesky Plant Trackers at the University of Minnesota, and other members of the UNM team. The course should take approximately four hours to complete. 

Have questions about observing with Pesky Plant Trackers? Connect with Pesky Plants staff and other volunteers via Zoom at one of their free, online events. Event dates and links to register here

How to participate

1. Create an account in Nature's Notebook and create a site for monitoring phenology. Need a tip on where to find these plants? Visit the University of Minnesota's Find Pesky Plants webpage. See our specifics of observing if you need more details on getting started.

2. Select your plants. Identify one or more wild parsnip (Pastinaca sativa), Japanese knotweed (Fallopia japonica), or Bohemian knotweed (Fallopia x bohemica) plants (or patches of plants if you can't identify individual plants) and add them to your site in Nature's Notebook. You will make observations on this plant or patch repeatedly through the season, so make sure it is conveniently located.

3. Sign up to receive our Pesky Plant Trackers campaign messaging. You will receive messages approximately monthly during the spring, summer, and fall, providing early results, encouragement, observation tips, interesting links, and campaign-specific opportunities. Don't miss out!

4. Observe your plant(s). Report what you see (yes/no/not sure) on your plant periodically following the instructions for monitoring. We encourage you to observe your plant(s) 2-3 times a week. However, we welcome any observations you can contribute. Check out our Phenophase Photo Guides for wild parsnip and Japanese knotweed for tips on identifying phenophases for these species.

5. Report your observations. Periodically log into your Nature's Notebook account and transfer your observations from your paper data sheet into the online reporting system. Alternatively, you can enter your observations directly using our Android or iPhone smartphone and tablet apps.

Who we are

Pesky Plant Trackers is a partnership between University of Minnesota's Department of Forest Resources and the USA National Phenology Network. This research is funded by the Minnesota Invasive Terrestrial Plants and Pests Center and is led by Dr. Rebecca Montgomery. Our team includes experts on the control and regulation of invasive plants. Contact Abbie Anderson ( for more information about how to participate. We are excited to have your help tracking these pesky plants!