What FOSC does

Friends of Sligo Creek (FOSC) offers events year round in support and appreciation of Sligo Creek and adjacent parkland. Litter clean-up and invasive plant clear-out events are among the most popular FOSC activities in the spring, summer and fall. FOSC also sponsors guided outdoor explorations of different aspects of Sligo Creek flora and fauna. A wide variety of other programs throughout the year educate neighbors and users of the park about Sligo Creek’s strengths and challenges. FOSC also monitors the creek, advocating for civic policies that will support a healthier Sligo.

FOSC invites you to visit the creek, volunteer at an upcoming event, attend a program, advocate for the Creek, and join FOSC.

Tomorrow night!
Thursday, March 20 at 7:30pm – 8:30pm
Microplastics in Sligo Creek
A talk with Dr. Jason Davison of Catholic University

via Zoom – Here is the Zoom Link

Dr. Davison is at the forefront of creating ways to predict where microplastic pollution ends up in a stream or river.

Microplastics are small bits of plastic, up to 5 mm, that are used in manufacturing or break down from larger plastics, clothing, toothpaste, cosmetics, and many other items. They release toxic chemicals into the environment through water, soil and air and can be ingested by wildlife and humans.

Through his research in Sligo Creek and elsewhere, Dr. Davison has developed innovative methods (such as 3D object detection for counting and classifying trash, particle tracking software, and underwater footage) to eventually give waterway managers the tools to identify plastic waste hotspots and prioritize sites for cleanup.

Sunday March 23 from 1:00pm – 3:00pm
Litter Hotspot Cleanup at Hillwood Manor Park

Join Litter Cleanup leaders Nick and Ed to tackle litter in this park along Sligo Creek. Please bring gloves if you have them. We will provide the trash and the recycling bags. All are welcome, but please register on the Parks volunteer page. SSL hours available.

Sunday March 30 from 1:00pm – 3:00pm
Litter Hotspot Cleanup at Long Branch-Garland Park
Meet at the Long Branch Community Center, 8700 Piney Branch Rd., Silver Spring, 20901

The whirlwind duo, Nick and Ed, will be leading this cleanup. Please bring gloves if you have them. We will meet at the Long Branch Community Center where there is ample parking, then walk across Piney Branch and down the trail to Long Branch-Garland Neighborhood Park. We will provide the trash and the recycling bags. All are welcome, but please register on the Parks volunteer page. SSL hours available.

Sat, April 12 and Sun, April 13
Sweep the Creek
Litter Cleanup

  • No preregistration needed, just sign in when you get there.
  • We will provide trash/recycling bags and gloves.
  • Students can earn SSL hours – bring your form with you.
  • Students age 13-17 must bring this waiver form signed by a parent or guardian.

The schedule of locations and hours for Sweep the Ceek cleanups on April 12 and 13, 2025.

Map of Sligo Creek Setions

News & Updates

FOSC in the News

Bring Your Own Bag Bill
Update: the County Council passed the Bring Your Own Bag Bill (Bill 24-24) on Feb 11th. The bill will go into effect Jan 1, 2026. FOSC had testified in favor of the bill and encouraged President Stewart to sign it.

FOSC’s efforts to support the plastic bag ban at the County Council hearing last Tuesday were noted in Bethesda Magazine’s Jan. 14th article, Supporters turn out for proposed plastic bag ban, citing environmental impact. Several members of the FOSC Advocacy committee testified in favor of the ban. Similar bans in Prince George’s and other nearby counties have been successfully implemented with little drama.

Winter scenes from Sligo and Long Branch

(Photos by Lenore Boulet – From footbridge over Sligo, Nathalie Peter – Long Branch near Becca Lilly park, and Susan DeFord – Snow on native coneflowers)

The FOSC Salt Monitoring Program measured extremely high salt levels throughout Sligo Creek, Wheaton Branch, Long Branch, and Takoma Branch starting with our first snow storm and continuing to date. We are collating the data as of Feb. 16, 2025. The initial report is available on the Salt Monitoring Initiatives page under the Water Quality Monitoring programs tab.

Email the Water Quality committee at [email protected] to learn more and become a tester.

Join FOSC

FOSC logo

Sligo Creek connects us. Please join FOSC and help protect and restore the Creek for everyone in our community. It’s simple to do and can be free if you wish. Membership gives you early notice of events and the FOSC newsletter.

You can make a donation too, either online (simple and secure) or by check to FOSC, P.O. Box 11572, Takoma Park, MD 20913. Thank you!

Support Friends of Sligo Creek and help the creeks thrive in 2025!

Your support is key to our success.

-Weed Warrior work sessions to remove non-native invasive plants threatening the parklands

-Sweep the Creek and Litter Hotspot clean-ups to reduce pollution

-Salt, E. coli, and other testing to understand threats to water quality in the watershed

-Advocacy work on many issues to protect the creeks

-Water WatchDogs pollution reporting as you see it occurring

-Natural history posters for the kiosks

-Outreach to neighbors in English, Spanish and Amharic


Donate to FOSC

FOSC Action Hub

Sligo Creek Water WatchDog mascot

Report water pollution ASAP!
Send an email to:
[email protected]

You play an important role protecting Sligo. Please report any pollution you see in the creek or heading into a storm drain ASAP, with photos, which help County investigators find and fine the pollutors.

A lone duck swimming in polluted water in between sewer pipes crossing the stream.

A lone duck swims in polluted water between sewer pipes crossing Brashears run near Maple Ave. in March 2024. (Sally Taber photo)

Winter 2025 Top Invasives

 Invasive: Italian Arum

Italian Arum is back in force around Sligo Creek and Long Branch. It has spread from nearby yards. One of the EDRR (Early Detection, Rapid Response) invasive species, it has many little “daughter” corms attached to its main corm which makes it difficult to remove completely. Dig it out carefully. Screen the loosened soil for small “daughter” corms. There is some evidence that spraying with glyphosate is effective at killing all its corms.

FOSC Videos

See many more on the FOSC Youtube Channel

 FOSC on iNaturalist

Pine Siskins at Wheaton Branch Ponds by Stephen Davies

Heard about FOSC on iNaturalist.org but uncertain how to navigate the site or contribute your own observations? Expert birder and iNaturalist… Read more

FOSC on YouTube

Support FOSC

Donate to Friends of Sligo Creek

FOSC on Facebook

Get Involved

  • Participate in your community
  • Meet your neighbors
  • Improve your surroundings
  • Enhance your skill set
  • Advocate for the Creek
  • Arrange a group activity for your club or group
  • Receive the monthly eNewsletter
  • Get early notice of events and special opportunities
  • Have your name forwarded to your Section Steward for hands-on events
  • Contribute to special projects
  • Fund outdoor events, expert talks, equipment for invasive plant/litter removal, the kiosks in the park, water quality testing, and more
  • Support FOSC’s outreach to schools, civic groups, and all communities
  • Tell us about your experience at a FOSC event
  • Suggest an activity
  • Voice your concern about an environmental issue