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Posts categorized invasive plant removal.

Mariton: Measuring Success

by Tim Burris, Preserve Manager

We have been actively removing Garlic Mustard (Alliaria oficinalis) for ten years now.  Garlic Mustard is an invasive plant that actually kills the soil mycorrhiza important to native plant health. In 2006, we pulled it along most of the trails where it was established, but I don’t think we did a thorough job the first year.  We just tried to get the big clusters.

We composted what we pulled that year, and that was important. Even after the plant is uprooted, the flowers can still develop into seeds.  For that reason it is important that you don’t pull it and drop it as you walk along a trail.  (That was a hard lesson learned through experience.)

2007 - one truck load.

2007 – One truck load.

In 2007, three high school seniors removed Garlic Mustard for their senior project. They did a much better job than we had the first year.  This photo recorded just one of the loads removed from the Kit and Chimney Rock Trails.  There were still some remote areas that they didn’t get, but these young ladies removed several truck loads that spring.

After that year we continued to aggressively remove Garlic Mustard each spring, and reached into areas farther from the trails. And each year there was less to remove.  We will probably never exhaust the seed bank, but we are making a positive effect.  In fact, all the work we had done previous to Hurricane Sandy controlled the invasion into the blow down areas.


2016 – Carrying out bundles to the loading area.

Jump forward to 2016. This year I scheduled a volunteer day, and then had a hard time finding areas to pull it.  We had a great turn out of volunteers who worked very hard.  We got most of what was on the property.  I’ll say that again.  We got most of the garlic mustard on the 200 acres of Mariton – and we came up with only three tractor bucket loads.

2016 - the results of 40+ human-hours of removal.

2016 – Three loads, the results of 40+ combined hours of removal.

Our success is measured in part by the “diminishing returns” of our removal efforts. The other (and perhaps more important) measure of success is the number of native wildflowers taking over the woods of Mariton.  If you recall at the beginning of this post I mentioned that Garlic Mustard kills soil mycorrhiza. Mariton’s soil is now healthier, and the native wildflowers and trees are too.  Now that is sweet success that you can see with your own eyes.  (You can see it on the wildflower walk I’ll be doing this Saturday.)

Mid-Atlantic Invasive Plant Conference August 4 & 5

By Daniel Barringer, Preserve Manager

In just a few weeks there will be a two-day conference on invasive plants and their impacts, sponsored by the Mid-Atlantic Invasive Plant Council and Morris Arboretum of the University of Pennsylvania.

This conference is held every two years and this year’s theme is applying research outcomes to management and restoration at the species, community, and landscape levels. The keynote will be by Johnny Randall, Director of Conservation Programs, the North Carolina Botanical Garden. Other presentations will include a case study of adaptive management in the Linville Gorge Wilderness, the latest research in controlling Japanese stiltgrass, and techniques to promote native pollinators.

These conferences are a good chance to learn more about controlling invasive plants; there’s a lot of expertise in the room. You can read more about the conference and registration here.

Mariton: Garlic Mustard Removal postponed

by Tim Burris, Preserve Manager

I scheduled a Garlic Mustard removal this Saturday, from 1 – 4 p.m.  But the Garlic Mustard is a little late this year.  I also have not received any calls or emails of people wishing to participate on Saturday. 

So, I have postponed the Garlic Mustard pulling to Saturday, May 4 from 1 – 4 p.m.  If you plan to come, please give me a call or email.  Thank you.

Citizen Science: Distribution of Look-Alike Buttercups

Happy Earth Day!

I usually offer some things to think about on Earth Day: reduce, reuse, recycle, purchase wisely, buy fresh/buy local, volunteer, support conservation organizations, plant native species, let your yard go a little wild, etc. And most importantly, get out and enjoy nature!

This year I’ll add another: participate in some citizen science. Here is one project to which I recently contributed:

You know that beautiful yellow flower that is carpeting local forests, particularly in the floodplains of streams and rivers? It is an invasive plant called lesser celandine, or by its botanic name: Ranunculus ficaria. Beautiful it may be, but because it so thoroughly carpets the floor of the woods, it is displacing a diversity of the native spring wildflowers that would otherwise grow there: trout lily, anemones, bloodroot, spring beauty, Dutchman’s breeches, trilliums, and native orchids, to name a few.


This is one species that I found a small population of at Crow’s Nest several years ago—about 25 plants. I have been working to get rid of them before they expand to fill our floodplain woods. Last year I found no new individuals (the location, on the way to the creek trail, is permanently flagged). But this year I found three, so I removed them promptly. This is the best example I have of “EDRR”: Early Detection—Rapid Response. It is much easier to manage an invasive species very early in the invasion process than once it is already covering acres of ground.

Several years ago I also found at Crow’s Nest Preserve a population of the native wildflower, marsh marigold (Caltha palustris):


It is superficially similar-looking, but has only five petals vs. lesser celandine’s eight, and it grows in clumps in wetlands rather than carpeting the ground completely. Our marsh marigold is growing in the standing water of vernal wetlands. Lesser celandine grows in wet floodplain woods but probably not in open water.

There is a citizen science project on to document the range and extent of these two species. Interestingly there are populations of both species locally that are separate but very close. Lesser celandine has shown up along the Horse-Shoe Trail on properties adjacent to (but fortunately for me, downstream from) Crow’s Nest Preserve. Marsh marigold grows in a wetland just a few hundred yards away on the preserve’s land. It’s an easy place to compare the species, their habitats, and perhaps the circumstances under which one site has been invaded and the other not.

I submitted my photos and records to the project on You can too!

Posted by Daniel Barringer on April 22, 2013.

Mariton: Events

by Tim Burris, Preserve Manager

On Saturday, April 27  (RESCHEDULED TO MAY 4) we will be pulling garlic mustard along the trails.  We have had good luck controlling this invasive plant at Mariton.  For the most part it has been concentrated along trails.  This spring, I am concerned that it could spread into the forest interior due to all the storm damage.  If it gets a foothold there, it will be much more difficult to control.  I am really hoping for a good turn out to help head off this forest pest that affects the health of the forest.  The event runs from 1 – 4 p.m., but people can contact me and work on garlic mustard at their own schedules.

On Tuesday, April 30, we begin the weekly bird walks.  The first Tuesday will be held at Mariton, and we will start at 8:00 a.m.  On following weeks we will be meeting here at 7:30 a.m., and then carpooling to other natural areas to sample a diversity of habitats and thus a diversity of bird species.

Saturday, May 4, from 9:00 a.m. – noon will be a Wildflower Walk.  Judging by what is poking up right now, there should be a good diversity of flowers in bloom for the walk.

Saturday, May 11, from 7:30 a.m. – noon will be the Migratory Bird Census.  This is near the peak of spring bird migration.  We hold the count as a chance to see several species of interesting new-tropical birds that pass through our area for a short time each spring.  Because a lot of these migrants like the tops of trees, we rely on our ears to help locate and identify them.

All of these programs are free, but please contact me if you plan to attend.  That way if weather changes our plans, I can let everyone know.

Garlic Mustard Removal at Mariton Wildlife Sanctuary

Saturday, April 28
1:00 – 4:00 PM
Mariton Wildlife Sanctuary, Easton, PA

Join Preserve Manager Tim Burris to pull this invasive plant where it grows along the trails. We
have made great progress over the last few years in decreasing the population of Garlic
Mustard at Mariton Wildlife Sanctuary. A concerted effort by volunteers will help us control it this spring.

Bring gardening gloves. New volunteers invited and encouraged to attend.

This event is free and open to the public. Preregistration is required. Please call 610-258-6574. Events may be cancelled due to inclement weather or low attendance.





Work Party: Invasive Plant Removal at Summerhill Preserve

Sunday, June 16
9:00 AM – 1:00 PM
Summerhill Preserve, Willistown Township, PA

Invasive plant species present an enormous challenge to Natural Lands Trust’s goal of maintaining healthy and diverse habitats. Invasive species quickly spread and outcompete native species. One way that Natural Lands Trust answers this challenge is by manually removing invasive species … and we need your help! Join Preserve Manager Mike Coll to learn how to identify and remove common invasive plants. Families and groups are welcome.

Breakfast, snacks, lunch, and water provided. Please wear sturdy shoes or boots and bring your water bottle, work gloves, and a raincoat if needed.

This event is free but registration is required. For individual and family registration, click here. For group preregistration, please contact Angela at or (610) 353-5587, ext 266.


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