by libby rhodes, october 8th 2021
As our summer of barefoot Intervale walks, Ethan Allen sunbathing, and parks and rec creemees has come to an end it is time for us, as well as our work, to transition into the fall. With returning to class and temperatures dropping, the work we are doing has begun to shift. While we are no longer babysitting goats and battling goutweed, one projects of ours had remained consistent. Volunteers! The three of us have developed our own volunteer group Saturdays at noon! While we loved working with Duncan at the intervale, this new group is ran entirely by us and takes place at the Ethan Allen Homestead! While our volunteer work this summer focused on knotweed and buckthorn, the autumn invasive we are tackling are oriental bittersweet and multiflora rose! In this post I will discuss the reason why we target some species in different parts of the year and about our Saturday volunteer groups!
Autumn Invasives:
Oriental Bittersweet
The species we are really focusing on this season is oriental bittersweet. As you pull up its tangled web of roots, it's hard to miss the bright orange color. What a perfect plant for a season that is characterized by its pallet of oranges and red leaves and halloween pumpkins. I actually was able to dry out the roots and use them to make a fall wreath for my door. This is the catch-22 of bittersweet actually. It orange flowers and red berries that ripen during the fall and persist throughout winter look beautiful in autumn arrangements and bouquets. The vines are easy to manipulate and are adored by florists and unknowing gardeners across the north east. While the wreath I hung up is fully dried out and without threat of spreading and establishing new bittersweet sites, the berries seeds remain viable and are a huge source of spread.
Oriental Bittersweet, also referred to as Chinese bittersweet, Asian bittersweet, round-leaved bittersweet, and Asiatic bittersweet is- can you guess it- an invasive vine native to China, Japan, and Korea. It's scientific name is Celastrus orbiculatus, meaning round evergreen- Celastras coming from the greek word kelastros, an evergreen tree,- and orbiculatus meaning round or disc shape, referencing the spherical shape of the vine. Bittersweet is not an evergreen, so my only interpretation of this name is maybe its bright red berries that remain throughout the winter. This perennial woody vine has 2-5 inch deciduous glossy ovular leaves in an alternate arrangement. The vine is a light brown with a white pith, and of course, those characteristically orange roots. The plant is well known by its small fruits that develop in the early summer, changing from green to a reddish orange as they enter the fall. It grows well in disturbed sunny areas but has a tolerance for shade allowing it to be found deep in the forests.
Now that you know how to ID it, let's discuss why bittersweet is such a problem. Bittersweet spreads rapidly through its seeds, which birds tend to enjoy and drop throughout the forest. It is hardy, fast growing, and aggressive. Unregulated it poses a major threat to native species, smothering and strangling even fully mature trees as it grows. If it doesn't strangle the plant, its heavy weight can uproot and cause significant breakage. For a place with such cold winters as Vermont, the added weight of the vine can be detrimental when combined with snow and ice weight. It is predicted Oriental Bittersweet can now hybridize with native bittersweet creating an even larger threat. So how do we get rid of it?
How to control bittersweet? If the plant is small enough, the best way to remove it is by slowly pulling it up by the roots. The plant can regrow through root fragments, so in bigger plants its is often not worth removing the entire plant. But, if small enough, you can carefully pull out all of the intestine like orange root system. Once the plants become bigger, it is best to cut at the base of the stem so the stem attached to the tree will die. It will resprout- so many recommend herbicide application, but cutting the plant weakens a lot of its reserves. Many say it is best to cut the bases at the beginning of summer when the majority of the plants reserves are stored in its leaves and stems. But it is argued if cut then the plants simply develop a stronger root system and trigger quicker resprouting. We are taking one last shot at it before frost comes to freeze over the stems and leave the bulk of the plant survive by its roots. Tackling woody perennials by a cut stump method in fall targets the energy stores in the roots. We are not currently using herbicides but are looking into the impact of using natural herbicides, like our vinegar-salt spray on the stumps of bittersweet.
While bittersweet is a huge threat we want to control, it is important and perhaps beneficial to recognize some of the benefits of the plant as well. Young leaves are edible when cooked and roots, stems, and leaves all have antiphlogistic (anti-inflammatory), antirheumatic (help slow rheumatic arthritis), depurative and tonic properties. The leafs can be applied externally to reduce swelling and help heal snake bites and stop abscess formation. And it is rumored to help treat paralysis, numbness, tooth and headaches. (Source: Plants for a Future). It has been studied for its tumor stoping properties as well.
Top Left: bittersweet scar on a tree (photo: Colin Hodge) , Top Middle & Right: bittersweet root wreath, Bottom Left: Bittersweet leaves, Bottom middle: Bittersweet vine, Bottom right: bittersweet berries in the winter
Multiflora Rose
Multiflora rose is really the only rose bush you will spot when out on a hike in the woods. Rosa multiflora, its scientific name, is native to China, Japan, and Korea but was brought to the United States in the 1860s to be used as a horticultural rose root stock that made a great ornamental. Conservation departments actually pushes organizations to plant this as a food source for native birds and mammals and actually to plant as a natural glare control in highway barriers, seeing it forms dense thickets. The plant rapidly took over however and now is a significant threat for native biodiversity. The plant produces such a large number of seeds, up to 500,000 per plant, that can remain viable for 10-20 years that are spread by birds. Multiflora can create dense thickets that outcompete other natives and destroy bird nesting habitats. However, it does create a very prolific and beneficial seed source to many natives, accessible even in the coldest winter when other plants cannot be found. Some still argue in favor of multiflora.
The perennial shrub typically has one stem and grows on average 10-15 feet. The branches have typically paired, curved thorns and alternate compound leaflets. In summer they produce white clustered blooms until the end of June. Following those are clusters of hard reddish fruits, known as rose hips. These berries are hard and require time to dry out to release seeds but have a long seed life and are spread rapidly through wildlife. However they are edible for humans! They can be foraged from fall to winter. The are edible raw or cooked and are very high in Vitamin C and Carotene. Mash them and use them for rose hip tea! It is an anodyne (painkiller), diuretic (increases urination), hypoglycaemic (increases glucose in bloodstream) and laxative. Some also claim it can be an antidote to fish poisoning. (Source: Plants for a future). Be warned! Just beneath the flesh of the fruit are hairs that can be an errant if digested so are best to be properly removed. But animals and humans alike can enjoy the benefits of the fruits.
Controlling multiflora rose is a long repetitive process. Mechanical cutting can be done anytime of the year but like the other plants is best in spring and summer unless using stump cut method of applying an herbicide, which the best time for is in the fall. Goats have been successful biological control for this plant. Interestingly enough, rose rosette disease is increasing range rapidly and while it poses a threat to noninvasive roses, it also impacts multiflora. It causes the plant to grow dis-formed and eventually after two years die.
Top Left: compound leafs, Top Right: bittersweet bush, Bottom Left: rose, Bottom Right: ripe rose hips
Autumn olive
Autumn olive, Elaeagnus umbellata, or Japanese Silverberry is an asian native brought over in 1830 as an ornamental plant with goals of erosion control and wildlife habitats. Unfortunately, now it poses a significant threat to native biodiversity. It is able to fix nitrogen, making it a great generalist, although it is typically found in disturbed habitats. It is spread by seed consumption from wildlife, mostly birds, but raccoons and opossums as well.
It is a shrubby plant, growing from 3-20 feet tall with thorny branches. It is known for its distinct 2-3 inch green leaves, that have a scaly silver bottom. Summer brings about clusters of small yellow flowers and fall produces red round drupes. One plant can produce 8 pounds of fruit! These berries actually are edible and incredible for you. They are potent with the carotenoid (fat soluble pigment) Lycopene. You might recognize the name Lycopene from tomatoes, which is how most Americans currently consume it! It is known to decrease the risk of lung, prostate, and stomach cancers as well as decrease LDL cholesterol and heart disease. Autumn olives contain significantly higher concentrations of Lycopene than tomatoes and also are rich with β-carotene, lutein, and phytoene, and vitamin C as well. (Source: northeast super foods) The berries are edible raw but are very sour. They could be better used in jams, sauces, wines, or anything else typically used with sour berries! The big identifier for the berries is the slight speckling (which is how to distinguish from many other look alikes).
Autumn olive though can transform ecosystems with low nutrients into ones with high, which while can replenish poor soil health, can cause many natives that do not do well in these conditions to die. It outcompetes natives are quickly establishes a shady cover that disturbs natural regeneration and succession.
Autumn olive is a difficult one to control. Cutting and pulling tends to only cause the plant to come back with more vigor and has to be done consistently for years. Like Bittersweet, the cut stump treatment method is the best way to tackle autumn olive and is most effective in the fall when the plant is returning its nutrients to its roots. It is best to do after a rainy day, when soil is moist.
Left: berries, Middle: flowers , Right: Bush
Our first Volunteer Group:
We didn't know what to expect before our first volunteer group. The air, while still clinging to that summer warmth, had a hint of that autumn chill. The sugar maples leaves, while majority still green, had begun to turn crimson and orange. Almost as if symbolizing our transition from the summer to the fall. Even more symbolic is our volunteers who showed up. We had a blend of new faces and old. Our Tuesday morning friends Theo, Ron, and Stephanie all arrived to support us and our new journey. The day was amazing, we removed massive amounts of bittersweet. We started by pulling young stems from the wooded and trail areas near the Abenaki heritage site and Fannies garden. These stems were still small enough to be able to easily pull up the whole root. In the mean time we cut down some buckthorn and multiflora rose bushes we encountered as well, but the predominant invasive in the area was bittersweet. We worked until we could find no more and then headed into the woods to work on some larger vines. For these thicker, more established plants, it is too energy intensive to remove the roots. There are too many fibers and separate growths from the main stem to be able to effectively remove the entire root, meaning more shoots will grow up from the remaining root in the following spring. So instead we cut the base of the vine cutting off the flow of nutrients to the bulk of the plant and therefore killing the growth that would eventually strangle the tree. Theo and Ron were actually able to fully remove an enormous bittersweet plant, stoping a future girdling of a tree. Nora and Marjorie's partners Colin and Drew both came out to help, as well as some of Nora's roommates. Together we took down bittersweet and spent a lovely Saturday together. Here are some photos Colin took, his photography instagram is @holincodge
@ Colin Hodge 2021
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