By Matt Bright
Founded in 1997, the Earth Sangha operates a volunteer-based ecological restoration program for the greater Washington, DC, region. The program is designed to conserve and restore the native plant communities that are essential to the region’s ecological health. At the heart of the program is our Wild Plant Nursery, the region’s most comprehensive source of native plants propagated from local, wild seed. In addition to local-ecotype native plant propagation, we help stabilize streams, control invasive alien plants, and restore forests, meadows, and wetlands. Our DC-area restoration work attracts over 600 volunteers annually, and has reached about 50 sites, nearly all of them on public lands.
If you visited Earth Sangha’s Wild Plant Nursery last year you may have noticed that we had an abundance of Virginia Sweetspire shrubs (Itea virginica) reserved for conservation projects. Earlier this spring, we finally started planting these into appropriate tidal wetland habitats in the hope of reestablishing a secure population.
Here is the story of how we got there.
Itea virginica is a smallish native shrub that usually grows between 3 and 8 feet tall. While common in the horticultural trade, it is increasingly rare in our wild areas. The plants in the trade are not necessarily local ecotypes but may have come from other areas where they are native. Most of these Sweetspire habitats are tidal wetlands—an increasingly rare habitat type in a
region that continues to see rapid development.
After a lucky year of good seed germination, Lisa Bright, our co-founder and Director Emerita, became increasingly concerned that this may be our last succession of Itea virginica, absent any effort to protect this species as populations along the Potomac suffer from erosion and high levels of siltation, and development threatens other tidal wetland habitats. We decided to develop a plan to donate those Sweetspire seedlings to reestablish them in appropriate habitats on public
lands.
First, we had to identify the appropriate habitats. While Itea virginica is frequently planted in a variety of conditions, in the wild locally, it has only been only found in tidal wetlands. So, we confined our search to those habitats. Next, we wanted to ensure that restoration plantings happened in conservation areas such as parkland or on conservation easements. From there, we assessed the general health of these sites, either hoping to find extant populations of Itea virginica (alas, we had no such luck!) or healthy populations of other tidal wetland species that indicated the Sweetspire could thrive there.
Those criteria led us to the Little Hunting Creek watershed. A search in SERNEC (the Southeast
Regional Network of Expertise and Collections—a vast effort to digitize herbaria specimens)
found a historical population near the mouth of Little Hunting Creek as late as 1975.
Rod Simmons’ Native Vascular Flora of the City of Alexandria, Virginia also lists Itea virginica as historically known in Hunting Creek where Cameron Run and Four Mile Run meet and form a cove (a separate creek from Little Hunting Creek farther south of where have been working), but otherwise suspected as extirpated from the City’s natural areas. The protected wetlands we visited also had other wetland shrubs, including Winterberry holly (Ilex verticillata), Buttonbush (Cephalanthus occidentalis), and Silky Dogwood (Swida amomum (syn. Cornus amomum)) and
perhaps most importantly for us, good populations of the tidal wetland specialist, Zizania aquatica, the annual, native Wild rice. Wild rice’s presence suggested to us a relatively stable tidal wetland environment. (Populations on the Potomac River tend to be less reliable because the tidal wetlands there are less healthy.)
Where We are Now and Plans for the Future.
As of this writing, we’ve already planted over 50 Itea virginica seedlings at a Northern Virginia Conservation Trust site along with the support of the Friends of Little Hunting Creek and hope to install additional seedlings in the fall. Separately, we’ve gotten support from Fairfax County Park Authority for a future replanting upstream at Martin Luther King Jr. Community Park. Both of these sites were not too long-ago tidal swamps that have rapidly become tidal marshes as the native green ash trees (Fraxinus pennsylvanica) have died from emerald ash borer. We’re
working to reintroduce ash in these sites too, but that’s probably best left to another blog post.
During a visit on June 2 nd , we were happy to see that the Sweetspire seedlings (still less than one foot tall at this point) are doing well and sharing space with other native vegetation. These include possum grape (Vitis cinerea), arrowhead plants (Sagittaria spp.), American groundnut vine (Apios americana), as well as native sedges, rushes, and others. There were also some invasive Murdannia spp. plants and Porcelain-berry (Ampelopsis glandulosa var. brevipedunculata) in the area. But it appeared that deer browse was pretty modest, which was good to see.
Photos by Matt Bright.
If you’re interested in joining us on our mission to preserve our local Itea virginica genotypes, please keep an eye out on our volunteer page at https://www.earthsangha.org/volunteer for upcoming events. If you have any questions, please contact me at mbright@earthsangha.org.
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