The most prominent feature of the Marie Butler Leven Preserve is not its forest but its main lawn, which adjoins the parking lot. (To orient yourself, click on the map links on the Native Arboretum main page.) Lots of people use the lawn for picnicking, dog walking, or just relaxing. But given the amount of mowing that it demands, perhaps the lawn is a little too prominent. (June 2004)

The Fairfax County Park Authority, which owns the Preserve, usually schedules the first mowing of the main lawn fairly late, to allow the buttercups that grow in it to bloom. The buttercups are widely admired—understandably! But as is probably apparent from this picture, this species (Ranunculus acris) can be invasive. It is not, however, a problem in the Preserve’s forest, or, as far as we know, in eastern forest generally. (May 2007)

Most of the Preserve is forested. The portion of the forest east of the main lawn is the best developed and the richest in terms of species count. This photo shows some of the canopy in the Preserve’s eastern forest. (July 2004)

A spring originates in the eastern forest—this is the most unusual feature of the Preserve—and flows through a little gorge into this pool. The water level in the pool varies greatly. Sometimes it’s nearly dry. (November 2004)

There is a house on the grounds (not in use as of April 2008), and on the back lawn, you will find this magnificent black walnut (Juglans nigra). We don’t know whether it’s a record tree, but it’s one of the largest walnuts that we have ever seen in this area. On the left, you can see the porch of the house. The two figures in front are Chris Bright (left), the Sangha’s President, and our friend Harry Glasgow, a member of the Park Authority’s Board of Directors and the Chair of the Fairfax County Tree Commission. (July 2007)

Unfortunately, the Preserve’s forest is badly infested with invasive alien plants. This portion of forest floor is covered with English ivy (Hedera helix). (August 2004)

Another invader of the forest floor: Common periwinkle (Vinca minor). The little shrub on the left is also an invasive alien species: Burningbush (Euonymus alatus). On the right is a native shrub: Spice bush (Lindera benzoin). (October 2003)

The plant that this volunteer is examining is a mature burningbush. When we started working at the Preserve, this invasive alien plant was the most common species in the forest understory. (July 2006)

Yet another ground-layer invasive: Japanese stiltgrass (Microstegium vimineum). At the Preserve, Japanese stiltgrass occurs in patches here and there along the forest edge. It’s not a pest under the closed canopy—or not yet anyway. (August 2004)

Still another ground-layer invasive: Japanese Pachysandra (Pachysandra terminalis). These ground-layer invasives are a serious threat to the Preserve’s native flora. There are still many native herbs growing in the Preserve’s forest, but they are at risk of being suppressed by the invasives. To see a few of the natives, view the “selected natives” slide show. (October 2003)

There are also several alien and highly invasive vines growing at the Preserve, especially along the forest edges. This one is called porcelainberry (Ampelopsis brevipedunculata). It’s native to northeast Asia. (October 2003)

Michael Rierson and Heather Schinkel, both of the Park Authority’s Resource Management Division, helped us develop our Native Arboretum agreement with the Park Authority. Their guidance, on matters both natural and bureaucratic, has been absolutely essential to the Native Arboretum project. Our other essential Park Authority resource is their colleague, Meghan Fellows—but she is much harder to capture on camera! (May 2004)

The Preserve is so large, and so badly invaded, that we had to take things one step at a time—and our first steps were fairly small. This picture was taken at the end of our very first planting at the Preserve. We had cleared a weedy patch composed mostly of invasives, and installed a bank of the native shrub, witch-hazel (Hamamelis virginiana). The witch-hazel came from our own Wild Plant Nursery, where we grew it from seed collected from local, wild specimens. (June 2004)

The witch-hazels have done well. Unfortunately, deer like to eat them, and the Preserve is heavily browsed. So we installed the deer protection that you can see here. Eventually, we’ll devise a more attractive deer fence. (October 2006)

This was what the forest edge looked like near the parking lot, when our project started. We chose this area for our native pollinator garden. (October 2003)

To begin work on the garden, we formed a partnership with the Langley High School Eco-Club, and with landscape designer Susan Abraham. As with the witch-hazels, the “native pollinator” plants came from our own nursery. Here, the Langley students begin installing the plants. Susan is the figure in blue at the far end of the bed. (May 2005)

The native pollinator garden has also done well. Like most gardens, though, it’s never really complete. We add new plants every year. (August 2007)

The bed maintains its interest until quite late in the year, although in the fall it gets a little unkempt. But all that growth is important food and habitat for the native insects and birds that use it. (A couple of those insects are featured in the “selected natives” slide show.) Every spring, we clean up the bed, and the show starts again. (October 2006)

We do a small amount of trail maintenance at the Preserve. We would like to improve the quality of the main trails—and the quality of the view from them!—but we think that there are a few too many trails at the Preserve, and we would like to discourage the use of several of them. (November 2004)

The Preserve’s eastern forest is topographically complex and susceptible to erosion; this area also contains the most diverse assemblage of native plants in the park. For these reasons, we have to work very carefully in here, removing invasives without damaging the natives, and doing a little additional planting as we go. Here, volunteer Matthew Bright tends a small area on the eastern forest slope. (September 2005)

The situation along the forest edge is very different. The vegetation in these places consists mainly of invasive alien plants and very tough natives that do well in disturbed areas. Our management strategy in such places is a lot more “muscular.” Here, students from the Lake Braddock High School environmental science program remove invasives from the fringe of forest on the west side of the Preserve, along Kirby Road. (January 2006)

Another photo of the same activity. Here, the students are starting in on a mass of porcelainberry and Japanese honeysuckle. Eventually we plan to transform this area into a native berry patch. (January 2006)

Our struggle with the invasives has not been an unqualified success. Here, volunteer Joe Herron attempts to rototill a patch of invasive vines. It didn’t work—the vines kept clogging the rototiller blades—so we went back to hand-pulling. (December 2006)

A large slash heap of invasive vines emerges from the future native berry patch. That structure on the lawn is a “bat hotel” installed by Nova (as in “Northern Virginia”) Bat World. As of April 2008, there were no guests. (December 2006)

All that invasive slash has to go somewhere. There’s far too much of it just to leave in the Preserve, so the Park Authority brings us dumpsters, which we fill and they haul off for chipping. Here, volunteer Bryce Carter celebrates his dumpster-stuffing prowess. (July 2006)

Another venue for brute-force invasives control is the patch of forest bordering the parking lot and lying immediately behind the native pollinator garden. The main problems here are English ivy, another invasive alien vine called wintercreeper euonymus (Euonymus fortunei), and burningbush. In the background, you can see the shed that the Park Authority donated to our project. On-site storage has greatly improved our efficiency. (February 2008)

Ivy removal can leave bare soil. Situations like this are manageable on level ground, as long as they are relatively small—and as long as there is a plan to cover the soil again and deal with any erosion that might result. Where the control area is large and sloped, more careful management is needed. To see an example, view the “restored habitat” slide show. (February 2008)

A group of high school students moves into an ivy-infested area. Unlike planting, invasives control can be a year-round activity, as it now is at the Preserve, although the target species change somewhat from season to season. (March 2008)

A patch of ivy rubble. Of course, these initial weeding efforts don’t kill the ivy entirely. The ivy will continue to resprout for several years, but successive weedings will eventually kill it. It’s important not to “let go” of an area once control begins, or the invasives will likely return and all the effort will have been wasted. (February 2008)

Alan Ford, our Park Authority IMA (Invasives Management Area) leader for the Preserve, takes a turn at the ivy. That big, downed tree behind Alan is (or was) a black cherry that had rotted out at the base, then collapsed during a thunderstorm. We left that large stump standing for wildlife. The rest of the tree has been cut. (December 2006)

You can see the remains of a barn in the forest behind the native pollinator garden. We are clearing the invasives off the walls, and cutting some of the trees that have grown up within and around it. When we first started working at the Preserve, these walls were not visible—we didn’t even know that they were there! (May 2005)

We are planning to create a “meditation garden”—a space that encourages reflection—within and around the barn foundation. But we have to decide what to do about the concrete blocks that form one of the walls. They aren’t very attractive. In the distance you can see the deer protection around the witch-hazel planting. (January 2008)

This is Tommy Ventre, our Tree Bank Program Manager, and our team of “Divas”—spot weeding specialists who are working a sensitive area in the Preserve’s forest. (November 2007)

It’s not all weeding! On almost every volunteer field day, we have a picnic. Yet another reason for joining us at the Preserve! (August 2007)

Our fully weeded restored habitat area in winter—an on-site demonstration of what our efforts can achieve. To learn more about this area, view the “restored habitat” slide show. (February 2008)