Table of Contents

• Updates from DCIST

• Native Species Highlights

  • What’s blooming now?

• Workshops and Volunteer Opportunities

  • Urban Forestry Workshop

  • Guided Stargazing

  • Gardening with Natives for Birds, Bees, and Butter …

  • Citizen Science Symposium

  • Other events

• News

  • Funding Update

  • Water Testing

  • Woody Invasive Plant Field Guide

  • New Regulations on Invasive Species

  • Dealing with the Aftermath of Buckthorn

• Invasive Species Highlight

  • European Frog-Bit

Updates from DCIST

It’s hard to believe that summer is winding down and we are moving into fall already. It feels like the field season just started! DCIST staff has been busy at work controlling priority invasive species, inventorying woody invasive species, and doing early detection surveys for high priority species like European Frog-Bit. To date, we have inventoried approximately 6,500 acres for high-priority invasive species and have treated 43 acres so far this year. While this may seem lower than expected, our inventory efforts are showing meaningful results: we are finding fewer new populations, which suggests our prior control work is making a difference. In addition, Phragmites treatments have just begun, and our contracted crews will be starting in mid-September.

Early detection surveys and management of European frog-bit (EFB) continue in Door County. The combination of ongoing control efforts and lower water levels this spring appears to have helped reduce EFB populations: no plants were found at two of the four known sites, while the other two were much reduced. This is encouraging, but we will continue monitoring these sites closely to prevent resurgence.

Unfortunately, a new EFB population was discovered in Sawyer Harbor this year. With help from DCLT and DNR, we hand-removed isolated patches, but further investigation showed that manual removal was not effective management option for this population. DCIST will worked closely with DNR to conduct targeted spraying to control the dense monoculture that had developed.

Native Species Highlights

What’s blooming now?

As summer fades and cooler air settles in the county, a new wave of blooms emerges to brighten the landscape. Fall wildflowers like goldenrods, asters, and sunflowers burst forth with vibrant yellows, purples, and oranges, heralding the changing season. These late-season blooms provide crucial nectar and pollen for pollinators preparing for winter or migration when many other flowers have finished. The abundant flora of Door County thrives in varied habitats making autumn a rich time for plant and wildlife activity.

Goldenrod (Solidago species): Goldenrods are plentiful here in Door County with approximately 15 different species. They are a sight to see in late summer and early fall with their vibrant yellow plumes lighting up fields, ditches, and even sandy dunes. The term Solidago originates from Latin, combining solidus meaning “whole” or “to make whole” with ago meaning “to act” or “to make”. This name was chosen due to the plant’s longstanding reputation for medicinal and healing properties - it was historically used to treat wounds and support health.

Goldenrods often get a bad rap for two main reasons. First, some species can exhibit weedy tendencies and spread relatively easily. While this may be undesirable in a garden bed or small landscape, it is actually welcome in natural settings like old fields where goldenrods provide valuable habitat. They have an extended bloom period and serve as a vital late-season food source for pollinators. Second, goldenrods are frequently blamed for causing hay fever, but the real culprit is ragweed. Goldenrod pollen is heavy and sticky, adapted for insect pollination rather than airborne dispersal like ragweed pollen, making goldenrods an unlikely trigger of seasonal allergies.

New England Aster (Symphyotrichum novae-angliae): The star of fall probably has to be New England aster, which adds vibrant purple and pink hues to the late summer and fall landscape. The genus comes from the Greek symph meaning “coming together” and trich meaning “hair”, in possible reference to the flowers anthers. The specific epithet means of “New England, USA”. This versatile plant can adapt to most garden locations. It can grow up to 6 feet tall, so it may require support to prevent flopping. Like goldenrods, New England aster provides an important source of nectar and pollen for a wide variety of pollinators in fall. door County boasts incredible diversity of asters suited to many types of habitats! Explore Prairie Moon’s website to see all the options available and consider adding this important flower to your landscape.

Workshops and Volunteer Opportunities

Urban Forestry Workshop

Guided Stargazing

The Guided Stargazing program offers an enchanting blend of education and entertainment, perfect for those eager to explore the wonders of the night sky. Led by an expert guide, participants will embark on a celestial journey to identify over a dozen constellations, several dazzling stars, our very own Milky Way galaxy, and perhaps even catch a rare glimpse of a distant galaxy speeding toward us from deep space!

Along the way, we’ll weave in fascinating tales from both Greek and Asian mythology, adding a cultural layer to the experience. A dash of astronomy science will also illuminate the cosmos, bringing the stars and planets to life in new ways. Designed for unaided (naked-eye) viewing, this program invites you to connect with the universe around you—but if you have binoculars, feel free to bring them for an even closer look. Join us for an unforgettable night under the stars!

Happening September 22 from 7:30 pm - 9:30 pm. You can register for this event here: Guided Stargazing

Gardening with Natives for Birds, Bees, and Butterflies

On Saturday, October 25 from 9:00 am to 1:00 pm join the Door County Master Gardeners Association for the fall seminar. This event will feature two presentations and includes lunch. Learn more and register for the event here: Fall Seminar 2025

Native Shrubs and Trees for the Birds and Bees. Learn about the rich diversity of woody plants native to the upper Midwest and the benefits of incorporating them into your home landscape to help attract and sustain a diversity of bird and pollinator species. Presented by David Garison Stevens, Ed Hasselkus Curator–Longenecker Horticultural Gardens at the UW-Madison Arboretum and an Honorary Associate Fellow, UW-Madison Department of Horticulture.

Why Monarchs Need Volcanoes. Learn about the importance of the sanctuaries where monarch butterflies overwinter. The temperate fir forests that cradle the butterflies sit atop high peaks of the Trans-Mexican Volcanic Belt. In a delicate balance between staying cool enough to conserve fat stores and warm enough not to freeze, the monarchs seek out a variety of microhabitats even as the climate changes around them. The tangle of relationships will astound you. Presented by Emily Stone, Naturalist and Education Director at the Cable Natural History Museum.

Citizen Science Symposium

Join the Ridges for their Third Annual Citizen Science Symposium on September 20 from 8:30 am to 12:00 pm. Celebrate citizen and community science that occurs throughout Door County with us on Saturday, September 20. This event will allow citizen scientists from The Ridges Sanctuary, Door County Land Trust, Climate Change Coalition, and Crossroads at Big Creek, along with other members of the public an opportunity to come together and share. There will be light refreshments and stimulating collegial conversation to start the morning followed by brief presentations from our citizen scientists representing the numerous programs that are happening throughout the year. 

The goals of this symposium are to celebrate the work of our citizen scientists and provide the opportunity to communicate this crucial work with others in our scientific community.

Register for the event here: Citizen Science Symposium

Other events

The above events only represent a few of the options that are available.

To see all of the events happening at Crossroads at Big Creek, check out there Event Calendar.

To see upcoming events with the Door County Land Trust, go here: Outings, Events, and Workdays.

To see more opportunities with the Ridges, see their Events & Programs page.

News

Funding Update

The invasive species control work conducted by DCIST is funded through a combination of state and federal grants, as well as donations from concerned citizens. Historically, part of this funding came from the U.S. Forest Service via the Great Lakes Restoration Initiative (GLRI). DCIST currently has an active grant through this program, but it is expected to be fully expended by the end of 2025. In 2024, the GLRI published a Request for Applications to continue funding critical invasive species work, and DCIST submitted a proposal. Unfortunately, we recently learned that the U.S. Forest Service will not be selecting any new projects for funding from this 2024 application cycle and will not announce a new funding opportunity until fiscal year 2026. Without this funding, DCIST will be forced to scale back invasive species control efforts.

DCIST is actively exploring other funding opportunities to ensure we maintain momentum in our invasive species control efforts. If you are able, please consider making a donation to DCIST to help protect Door County’s landscapes and community from the risks posed by invasive species. Every dollar you contribute helps prevent invasive species from becoming an unmanageable threat. Your support is more critical than ever to keep this essential work going. Together, we can make a difference. To make a donation, please visit our website: DCIST Donation.

Water Testing

Woody Invasive Plant Field Guide

Invasive trees, shrubs, and woody vines pose a serious threat to natural areas in the Great Lakes region, out-competing native plants and damaging wildlife habitat. Invasive woody species can also encroach on farm fields and pastures, prevent the regeneration of trees in timber stands, and restrict outdoor recreation by growing over trails and access points. Additionally, some woody invaders provide ideal conditions for ticks that transmit diseases to people. 

The Woody Invasives of the Great Lakes (WIGL) Collaborative brings interested partners together to consolidate information on woody invasive plant species. Our goal is to provide residents from all walks of life with the information they need to manage invasive woody plants and restore habitat for native plants and wildlife around the Great Lakes. You can buy a copy here: Field Guide To Woody Invasive Plants

New Regulations on Invasive Species

On July, 2025, Missouri passed a new law halting the sale of 6 invasive plants, including burning bush (Euonymus alatus), Japanese honeysuckle (Lonicera japonica), wintercreeper (Euonymus fortunei), and Callery pear (Pyrus calleryana). The implementation date for the legislation is August 28, 2025. The legislation allows four plants in the bill to continue to be sold through January 1, 2027, and two others to be sold through January 1, 2029. Across the Midwest and Great Lakes region, there has been increased action on regulating Callery Pear.  Pennsylvania classified Callery pear as a Class B noxious weed in 2021. Callery pear is illegal to sell, grow, or plant in Ohio. Minnesota is in a phase out period and Illinois and Wisconsin have proposed that this tree be regulated. Check out our  blog posts “Pears on the Loose!” and “What to Plant Instead” to learn more about this tree and what is being done to help curtail its spread and impact.

Ontario has provided an updated invasive plant list (2025) based on the “Invasive Exotic Plant Species Ranking for Southern Ontario” from the Society for Ecological Restoration with 4 levels of designation ranging from “Top Priority” to “Species to Watch”. The Midwest Invasive Plant Network maintains a list of all plants listed and/or regulated as invasive in our region. Access the list here.

Dealing with the Aftermath of Buckthorn

The Cover It Up Project, demonstrates how densely planted native species after buckthorn removal can drastically reduce the likelihood of buckthorn regrowth. By filling the void left by cleared buckthorn with competitive native grasses, wildflowers, shrubs, and trees - especially those that hold their leaves into fall and shade the soil - the project has achieved up to a 10-fold reduction in buckthorn return compared to unplanted sites. The restoration approach not only suppresses buckthorn, but also limits other invasive species and promotes healthier native plant communities. They have released a Guide to Forest Understory Revegetation to help guide your restoration.

Invasive Species Highlight

European Frog-Bit

European Frog-bit (EFB) is a small, floating invasive plant that can quickly invade shallow or slow-moving waters. It forms dense colonies of interlocking mats that drastically reduce light availability for native aquatic plants and restrict the movement of large fish and diving ducks. EFB was first documented in Wisconsin’s Oconto County in 2021 and was likely introduced to the United States through the ornamental plant trade.

In Door County, this species was first observed in 2022 in two isolated populations. Since its discovery, DCIST has worked closely with the Wisconsin DNR to conduct manual removal efforts and early detection surveys at high-priority sites across the county. These surveys led to the discovery of three additional EFB infestations. Early detection is critical to prevent populations from becoming well-established in Door County’s high-quality aquatic habitats.

EFB plants produce leathery, round to heart-shaped leaves that measure 0.5 to 2.5 inches across. Small white flowers with three petals bloom in late summer. Although the plants do flower, viable seed production is rare; the species primarily spreads through vegetative reproduction via turions (overwintering buds).

EFB can be confused with native floating plants such as waterlilies and water-shield. Water-shield has oval leaves without splits and produces maroon-colored flowers, while waterlily leaves have splits but are more rounded and feature pointed lobes.

Due to its recent arrival in Wisconsin, control methods for European Frog-bit are still being refined. Manual removal is effective for small, isolated populations, while chemical treatments have been applied to larger infestations.

For more information, please visit the Wisconsin DNR page at https://dnr.wisconsin.gov/topic/Invasives/fact/EuropeanFrogbit.html. DCIST and the WDNR is asking the public to join in efforts for monitoring for this species.

European frog bit is a prohibited species under Wisconsin’s Invasive Species Rule Chapter NR 40. Prohibited species are not currently found in Wisconsin or are found in very low density and few areas. Prohibited species are likely to cause significant environmental and economic harm or harm to human health. The NR 40 Rule makes it illegal to possess, transport, transfer, or introduce invasive species listed as a prohibited species in Wisconsin.  If you find European frogbit in Door County, be sure to report it to DCIST or using the GLEDN app!