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Creative Uses for Invasive Plants

The positive results of removing invasive plants are often evident in the return of native species to the area. But what happens to the plant material that has been removed? Does it have to be destined for the incinerator or landfill? Apparently not: artists and others are finding responsible ways to utilize the invasive plant material they remove. Highlighted here are some innovators who have found ways to creatively utilize the invasives they remove from the landscape.

Do you have your own creative use for an invasive plant that you’d like to share? Email your idea to, subject line Use Your Invasives, and it may appear in a future issue of the Newsletter.

Russ Cohen: Eats his Invasives

When not at work for the MA Division of Ecological Restoration, Russ teaches courses and leads walks with a focus on foraging. A wild foods enthusiast, he has been identifying and consuming edible wild plants for over 40 years. In addition to native plants that helped form the diet of indigenous populations in the New England area, Russ is happy to nibble on the newer arrivals, including some plants that are now recognized as invasives.

Of the 66 species featured in the booklet A Guide to Invasive Plants in Massachusetts, Russ reports that at least 20 are edible, including some of his favorite plants for eating (Japanese Knotweed, Black Locust, Dame’s Rocket, Common/European Barberry, and Autumn Olive); and Russ believes that as far as most ecologists are concerned, they’d be thrilled if people picked and ate as many of these and other invasive species as they possibly could, provided they don’t help them spread in the process, which is easily avoidable.

Here Russ shares one of his recipes utilizing Japanese Knotweed.

Russ Cohen’s Sour Cream Knotweed Crumb Cake

For this recipe, you’ll need to harvest Japanese Knotweed stalks at the “wild rhubarb” stage, which typically shows up around the first week of May in the Boston area. Look for stalks about 18-24 inches long, select the fattest stalks you can (at least ¾ inch in diameter – they’re easier to peel that way), cut at ground level, lop off the top cluster of leaves and bring the stalks home. Once you’ve got them home, peel the very outer layer (which is stringy) off of each stalk; Japanese Knotweed stalks are hollow, though, so don’t peel too deeply or all you’ll have left is the hole. You can eat the peeled stalks raw if you want (their tart, juicy, crunchy texture, and flavor is somewhat like that of a Granny Smith apple), or just chop them up for use in the recipe below or just about any other recipe calling for rhubarb.

For cake:
1 1/2 cups granulated sugar
3/4 cup butter, softened
3 eggs
1 1/2 teaspoons vanilla extract
2 1/2 cups all-purpose flour
2 teaspoons baking powder
1 teaspoon baking soda
3/4 teaspoon salt
1 cup dairy sour cream
5 firmly-packed cups peeled Japanese Knotweed stalk pieces (chop or knead the peeled stalks into small pieces <1” long), tossed with 1/2 cup flour, 1 teaspoon cinnamon, 1/4 teaspoon nutmeg and 1/4 teaspoon allspice in a bowl

For topping:
1/2 firmly packed cup brown sugar
1/4 cup all-purpose flour
1 teaspoon cinnamon
1/4 teaspoon nutmeg
1/4 teaspoon allspice
1/4 cup cold butter, cut up into small pieces

Preheat oven to 350ºF. Grease a 13” by 9” baking pan. Cake: Beat sugar and butter in a large bowl on medium speed until blended. Add eggs and vanilla and beat until creamy. Mix flour, baking powder, baking soda and salt in a bowl, then add to the creamed mixture alternatively with the sour cream, mixing well. Stir in the floured/spiced Knotweed pieces and mix well, then pour the cake batter into the baking pan and spread evenly. Topping: Place brown sugar, flour, and spices into a food processor and pulse until well-blended; then add the cold butter pieces and pulse until the entire topping mixture is uniformly crumbly. Sprinkle the topping evenly over the batter. Bake at 350ºF for 50-60 minutes or until a wooden toothpick inserted into the center of the cake comes out clean. Cool on a wire rack; serve warm. Makes 15 good-sized servings. Any leftovers can be stored in the refrigerator for use in the next few days or frozen for longer storage.

Russ Cohen’s Strawberry Knotweed Pie. The recipe can be found in his foraging book, Wild Plants I Have Known…and Eaten, available from the Essex County Greenbelt Association.

Nancy Reilly: Bittersweet as Building Material

Text and photos by Emma Sundberg

As we turned down the street to Nancy Reilly’s house and studio, we knew immediately that we had arrived, even without searching out the street number scrawled in our notes. The street-facing porch boasted two comfy, twining chairs and a door decorated with a large, looping wreath of bittersweet vines.

A bittersweet chair and wreath (with berries removed and destroyed) greet visitors to Nancy Reilly’s home.

Driven by a strong do-it-yourself attitude and a passion for repurposing invasives, Nancy has spent the past eight years exploring the endless uses of Asiatic bittersweet in both furniture building and home décor. A tour of her home reveals a hand-made piece in almost every room, yet they blend into the overall furnishings so well that each piece comes as a surprise when she points it out. Bittersweet vines stand alone to create mirror frames, window swags, and dainty nests or are paired with granite and other stone to provide sturdy tops for benches and tables and bases for lamps.

Each piece is full of the charm that comes from individually handcrafted art. In describing her creative process, Nancy agrees that each creation is different because her stock of materials is constantly changing. No two vines curve and coil in exactly the same way. While this unique quality of the material is what now lends whimsy to each construction, initially the irregularities of bittersweet provided a major obstacle to the novice woodworker

When Nancy first turned to furniture making, she took a traditional woodworking class. After learning the basic skills she wanted to explore the use of atypical materials, such as bittersweet vine. Told that such materials would never work in furniture making, she started experimenting on her own. Her initial attempts were indeed doomed to become firewood; however, over time she learned to work with the material and treat each creation as a puzzle, trying and retrying different segments of bittersweet until the pieces converged into an aesthetic and stable structure.

Large pieces of bittersweet provide a substantial base for a stone table top.

The bittersweet vines that star in the majority of Nancy’s furniture are culled from local conservation areas, mostly by Nancy herself. When harvesting, Nancy cuts out the midsection of the vines, being careful to avoid the berries, the removal of which is illegal. Several conservation groups have granted Nancy permits to remove bittersweet. While these permits allow Nancy to supply herself with plenty of raw material, she admits that the permit process may be a hindrance to other artisans who wish to work with invasives such as bittersweet. The end of year reports required for the maintenance of harvesting permits would prove very difficult for groups such as schools, who could otherwise educate students as to the importance of removing invasive flora to protect native species, while also providing inexpensive material for woodworking classes.

In her workshop, Nancy shows the base of a vanity that is beginning to take shape.

Despite the inconvenience of the strict rules surrounding the removal of invasives, Nancy hopes that more people will find uses for invasive species such as Asiatic bittersweet. Her own bittersweet furniture business demonstrates that creative uses for invasive species can indeed flourish.

Nancy cuts her own bittersweet as well as receiving select pieces from Rebecca Chizzo of the Sudbury Weed Education and Eradication Team (S.W.E.E.T.).

Louise Barteau: Papermaking from Invasive Non-Native Plants

Text and photos by Louise Barteau

I spent the past weekend making pulp for my next Papermaking from Plants workshop to be held at Philadelphia’s  Rittenhouse Town Paper Arts program. I use almost exclusively non-native invasive plants, as long as they have not been sprayed with chemicals. I have made paper for workshops from Japanese knotweed, phragmites, Amur peppervine, oriental bittersweet, Japanese honeysuckle, hostas, daylilies, and Japanese stiltgrass.

Buckets contain plant material soaking for backyard papermaking.

The basic process is to cook the plants in a base solution that breaks down the cellulose plant material. This takes longer for woody plants (like peppervine) and less time for fresh green herbaceous plants like (daylilies). After careful rinsing what remains are the lignin fibers. These fibers are then beaten by hand or machine and mixed with water to form the pulp for the vat. Sheets of paper are formed by pulling up the fibers onto a screen. The sheet is then released from the screen, pressed, and dried.

Paper from knotweed, stiltgrass, and daylily (left to right) exhibit unique color and texture.

There are many variations on this process. Right now I am making use of the summer and my backyard to process large quantities of pulp. I leave a big pot cooking almost all the time on my back porch – only emptying the cooking water at the end of the season. If it rains, I use rain and/or water collected in the rain barrel to rinse the fibers. A professional fiber beater can cost thousands of dollars but a stick, a rock, and a blender will do a pretty good job, too.

Water accumulated in rain barrels works well for rinsing plant fibers.

Papermaking is a process that teaches me how to make use of the weather and the season. I like to use the heat of the sun to dry harvested plants or freshly made sheets of paper. Rainy days are good for rinsing fibers. Every bit of water I use to make paper also waters the garden full of native plants. Stalks left to overwinter will give up their fiber easily, processed by the wind and the cold.

Summer sun speeds drying of harvested plant material.

Winter cold and wind break down plant material, and it will be easier to process in the spring.

Transformations and perception have always informed my work as an artist. It is very satisfying to make something beautiful out of something which is perceived not to have value. But it is even more fun to share that process with others at the Rittenhouse Paper Arts program every summer.

It is a labor intensive sort of work – all the better to share it with others. There is a Zen quality to pulling a sheet of paper that rewards everyone who tries, whether you are drawn to try papermaking from your love of plants or your love of paper. You learn something new about a plant when you make paper out of it – and I haven’t had to send a bag of plants to the landfill for years.