January Tree Planting: The Buffer Brigade showed up in early January to plant scarlet oaks in the upper portions of Curtis. Chrissa has done an amazing job of tracking all the planted trees: when and where they were planted, and keeping them labeled so that we can follow their progress and learn from what does and does not do well.

Clearing at Curtis continues: Given the invasive strangulation of vines and multiflora roses that once was killing the Rock Creek Buffer trees, it was a tremendous mark of progress that the Buffer Brigade turned its attention to the hillside above the dog park and along the parking lot. This new effort was possible because so much clearing and invasive removal had been completed along both sides of Rock Creek. This new initiative should take many months but will rescue the beleaguered trees and bushes along the parking lot hillside. It will also open up the area for additional native shrub and tree plantings in the spring. We expect a significant infusion of new labor, when the current Master Watershed Steward class graduates this spring. Each graduate will need to complete 50 hours of volunteer work their first year. We hope the Curtis project intrigues and draws in a number of them. Our own Ed Vanderloop is among the new trainees.

Monitoring Rock Creek: Chrissa and Geoffrey completed the monthly monitoring and chloride measurements. During the monitoring day, we noticed significant bank collapse in the upper section of Rock Creek in the arboretum, as well as excessive muddiness in the feeder creek from the parking lot. In the photo below, note the muddiness and the backed-up water just below the parking lot. We were concerned about the conditions that caused this.

Winter Salt Watch: The January salt readings were also high—as in past months. We have communicated this data with the Izaak Walton League, who manages Winter Salt Watch, and they report that many of the mid-Atlantic states are experiencing high chloride levels, even though the roads have not been salted for a long time. We hope FOCA will find ways to address this in the community.
Keystone Ten Million Tree initiative of the Chesapeake Bay Foundation: In late March, the Buffer Brigade will be receiving 500 FREE understory bushes from the Keystone program. These will be interplanted around the trees we’ve already planted, to try to restart the forest understory and provide native plant competition for the invasive species. FOCA is now an OFFICIAL PARTNER of the Keystone Ten Million project!! This means we will be able to easily order trees and bushes in the future (the program is set to run through 2025). Included with the bushes will be high quality tree tubes and stakes, so that deer protection will be built into the planting. Donna and Wes have MOST GRACIOUSLY AGREED to receive the seedling trees and tubes/stakes earmarked not only for FOCA, but for four or five other Montgomery County MWS projects, in their driveway. We will do our best to get all these trees and bushes out to the various projects ASAP.

2020 Curtis Riparian Buffer Update

Thanks to all of you who have stopped by to offer encouragement and help over the past year as we continue our invasive remediation work along Rock Creek. I feel like we could use one of those “Under Construction” signs as we clear new areas of vines and other plants damaging or killing trees.

Ballroom covered in knotweed and vines

Ballroom after cutting vines and knotweed

We now have a crew of 8 volunteers! We’ve made more progress than we ever thought possible in one year, especially with a pandemic raging. We started the year at the upper reaches of the creek in the arboretum where a combined sewer overflow directs street runoff into Rock Creek. We’ve installed erosion markers which we are monitoring to see the effects of storm damage. Each month we assess the water quality and flow so we can get a fuller picture of the health of the stream over time. We also did our first detailed annual wildlife habitat survey. A healthy stream isn’t just important for the animals that rely on it, but it’s important for our human health as well. The water from Rock Creek is part of the watershed that supplies our area with drinking water! Water that runs off our streets eventually ends up in our showers or water glasses, after treatment of course. The cleaner the water is before treatment the better for us and the planet.

Fungus growing on a dead tree

Trees are an important part of creating a healthy stream ecosystem. They provide cooling shade necessary for fish, frogs and insects. Tree roots also keep soil from washing away. Erosion harms animals that live in the water. Curtis Arboretum has lost many trees along Rock Creek from vine damage. This year we’ve freed 100+ canopy trees and 200+ understory trees and bushes from strangling vines. Our work has included both sides of Rock Creek and we’ve planted a total of 29 native trees to replace some of the trees we’ve lost. We’ve also seen native flowers reappear from seeds lying dormant in the earth waiting for the opportunity to grow. 

Native flowers

While working, we’ve seen deer, skunk, herons, woodpeckers, migratory warblers and scarlet tanagers, hawks, vultures, as well as other more common birds like robins, wrens and catbirds. The stream is home to minnows, water striders, and frogs. We’ve even spotted iridescent jewelwing damselfly! Even with all this abundance of species, Rock Creek still needs our help to allow more sensitive species to thrive. This year, to see if salt is affecting stream biodiversity, we’ve begun a salt monitoring program. We made a baseline measurement and we’ll do measurements after salt application on streets occurs later this year. 

Young oak planted in the cleared Ballroom

It’s been an exciting year and we’ve uncovered gorgeous hidden spaces and even given them names like: the Ballroom, Spice Bush Grove, Skunk Hallow and Jenga Dam. Take some time and explore Rock Creek, walk softly and you may see some of the creatures that inhabit this urban wilderness.

 Chrissa Pedersen & Geoffrey Selling

Friends of Curtis Arboretum

Riparian Buffer Volunteers

What ARE All Those Piles?

What ARE All Those Piles?

    If you walk or even drive through Curtis Arboretum, you’ve probably noticed large piles of sticks, vines and other debris piled near the dog park entrance or at the back gate of Curtis Arboretum.

Those piles are plants—that don’t belong at Curtis. Long ago, this area was filled with native trees, bushes and ground covers.  Gradually, people introduced (both intentionally and accidentally) other kinds of plants that didn’t belong here. These invasive species, as they are known, are aggressive, spread easily, choke out or smother native species and aren’t eaten by our local insects or fauna.  In other words, there are few natural limits on their spread. 

    Over the decades, two woody vines in particular (Oriental bittersweet and porcelain berry) have covered the ground, climbed and entwined around the trees, and buried many shrubs and smaller bushes. Many older trees have died as the leafy vines blocked the sun from the trees’ leaves. The enormous weight of vines have broken mighty branches and weakened tree structure.

    A large group of young trees, planted around 2009, never made it because they were choked out by the vines. Dead and weakened trees diminish the all-important protections that streams, like Rock Creek which runs through Curtis, get from their riparian buffers (the formal name for stream borders of native trees and plants). 

    

    Trees provide many benefits to the stream and environs.  They shade and cool the water, allowing it to hold a greater concentration of dissolved oxygen that stream critters need to breathe.  The roots of trees stabilize the banks so that the soil is not washed away.  The roots also filter runoff from the land---removing pollutants.  The fallen leaves and branches create habitat and nutrient sources for tiny stream critters.  Healthy streams have wide buffers of native trees and shrubs, as well as a ground cover of ferns, grasses and wild perennials.

    Rock Creek needs a lot of help---specifically, the trees and native vegetation.  But before those can be planted to restore the riparian buffer, the invasive tree-killing vines need to be removed and brought under control.

    

    Enter two volunteers: Chrissa Pedersen and myself, Geoffrey Selling (more about us in a future post!). For the past two years, we’ve been cutting, digging and pulling vines and, more recently, hauling the debris out.   Those are the piles you may have seen. 

Geoffrey holding part of a vine cut from a tree

    Somewhere, down the road, we hope to see the Rock Creek buffer restored with an abundance of tall leafy trees and native vegetation.   When the corona virus crisis is over (it WILL happen!!), we will be able to resume regular Friends of Curtis Arboretum (FOCA) workdays and volunteer help will be enthusiastically sought.