At the end of an invasive plant removal you can expect sore muscles, some pebbles and dirt in your boots, a deep thirst for a crisp glass of water — oh, and also, a pile of invasive plant debris!
How you dispose of this material matters. You risk worsening or spreading an infestation if you handle invasive plant debris like typical yard waste that can be composted or chipped. Practicing responsible invasive waste management needn’t be confusing; we are here to help point you in the right direction.
The Natural Neighbors Program offers free property consultations to help optimize your land for native biodiversity. During these visits we point out opportunities for you to add beneficial features like nest boxes, water sources, and native plantings. We will also identify hazards and invasive plants that can be removed and replaced to better serve the island’s ecosystems.
If we find an invasive infestation on your land, we provide invasive fact sheets to help you identify problem plants, and offer an opportunity to join the Invasive Plant Brigade (IPB). The IPB is a volunteer powered labor co-op that unites Natural Neighbors to help each other remove invasive plants. You volunteer time on someone else’s land and in turn earn the same amount of time on your own land.
During our work sessions we prepare your invasive debris for whatever disposal method you pick. Typically, we stack debris on tarps for drying or pack them into contractor bags for solarization. While the IPB doesn’t handle the disposal itself, we can help you choose a method that makes sense for you.
With this is mind, I encourage you to familiarize yourself with the disposal methods described below. Taking all of this information in can be an intimidating task, but you can always reach out to us for further guidance. My email is rgraygor@biodiversityworksmv.org.
Important Notes
These guidelines are intended to help you safely dispose of terrestrial invasive plant material that has been mechanically removed. Disposal must be conducted in a way that prevents further spread, as detailed below. Never dispose of invasive species in wild or preserved areas. This post does not address how to conduct a removal session, disposal of chemically treated invasive species waste, or disposal protocol for aquatic invasive plants. However, these topics may be discussed in future posts.
Please note that to ensure compliance with the Massachusetts Wetlands Protection Act, invasive removal projects in wetlands, rivers, streams, ponds, and in surrounding buffer zones, must be reviewed and approved by your local Conservation Commission before starting work. You must also obtain an applicable permit before managing invasive plants near state-listed rare species habitat. If you are uncertain about the permitting requirements for a vegetation management project, an informal conversation with your town Conservation Commission is a good place to start.
Words of Wisdom
For the best results, begin tackling your infestation early in the growing season before the plants flower and go to seed. Doing so will exhaust the plant as it pours energy into growth and reproduction, leaving it vulnerable. I urge you to report invasive plant populations to EDDMapS and iNaturalist.
On-site disposal of invasive waste is highly recommended to minimize the risk of spreading an invasive species elsewhere. Transportation of invasive plants may be subject to restrictions, and disposal must be done in a way that prevents further spread.
Woody Plants
Woody plants consist of trees, shrubs, and woody vines. The following invasive species are considered woody. Woody vines are marked with an asterisk:
- Acer platanoides (Norway maple)
- Acer pseudoplatanus (Sycamore maple)
- Actinidia arguta (Hardy kiwi, Tara vine) *
- Ailanthus altissima (Tree-of-heaven)
- Ampelopsis brevipedunculata (Porcelain-berry; Amur peppervine) *
- Berberis thunbergii (Japanese barberry)
- Celastrus orbiculatus (Oriental bittersweet; Asian or Asiatic bittersweet) *
- Cytisus scoparius (Scotch broom)
- Elaeagnus umbellata (Autumn olive)
- Euonymus alatus (Winged euonymus; Burning bush)
- Frangula alnus (European buckthorn; glossy buckthorn)
- Hedera helix (English ivy)*
- Ligustrum obtusifolium (Border privet)
- Lonicera japonica (Japanese Honeysuckle)
- Lonicera spp. (Asian bush honeysuckle) *
- Pyrus calleryana (Callery Pear; Bradford Pear)
- Rhamnus cathartica (Common buckthorn)
- Robinia pseudoacacia (Black locust)
- Rosa multiflora (Multiflora rose)
- Rubus phoenicolasius (Wineberry; Japanese wineberry; wine raspberry)
- Salix atrocinerea/Salix cinerea (Large Gray Willow/Rusty Willow)
- Wisteria sinensis (Chinese Wisteria) *
Disposal Methods
Drying and Brush Pile
Before flowering, plants can be pulled and left on-site on tarps, pavement, or another impervious surface with roots exposed to fully air dry in a sunny spot for two weeks or more. After the material is dead and dried, it can be added to a brush pile on-site, where it should be monitored regularly for any regrowth. Brush piles work well for larger shrubs and medium-sized tree debris. Some woody vines may be able to re-root in a brush pile even after drying. Consider a different disposal method for these high risk species, as marked with an asterisk above, or form a covered brush pile using an impervious barrier below and above the pile.
If the plant has flowered or gone to seed, the reproductive parts should be clipped and put in a black plastic bag to solarize. More information on solarization can be found below. The rest of the material can be dried and added to a brush pile. We recommend you form a covered brush pile if a plant has flowered or fruited by using a tarp underneath your pile and a tarp on top of the pile.
Solarization and Brush Pile or Landfill
Woody invasive species, especially vines and smaller plants, should be removed and placed in thick black contractor bags to solarize in the sun for at least two weeks. This process will heat and kill the contents if done correctly. For successful solarization, the bag should be tightly secured and without any holes. Check that the solarized materials are fully dead before adding them to a brush pile or bringing to a local waste processing station. Check with your town’s waste transfer station to see if they accept invasive species debris.
Leave Dead Wood Standing
The best option for large trees and shrubs is girdling, which kills the target species but leaves the dead wood standing. To girdle a tree, remove a thick strip of the sapwood and outer bark around the entire circumference of the trunk at about hip-height without damaging the inner heartwood core.
The outer sapwood of the tree transports the products of photosynthesis down to the roots, while the inner heartwood transports products from the roots upwards. By cutting off the flow of nutrients to the roots, the tree will slowly starve as the heartwood continues to pump energy up to the top of the tree without receiving anything in return. The girdled species is likely to die within two years, and remain standing as deadwood for habitat.
Girdling is most effective in the spring as nutrients begin moving throughout the tree — think maple sugaring season. If the heartwood is damaged, the tree might begin sending sprouts below the girdle. If this happens, regularly cut off any new growth until the tree dies.
The Invasive Plant Brigade (IPB) is a useful resource to girdle trees. We provide the tools, expertise, and numbers. All that’s left for you to do is leave the dead wood standing.
Burning
Contact your local fire department to inquire about obtaining an open burn permit. Open burns are not permitted in every community, and are subject to strict restrictions in Massachusetts. If you obtain an open burn permit from your local fire department to burn invasive species debris, make sure you follow their guidelines carefully.
Special Considerations
In some cases, specific parts of some woody shrubs and trees can be chipped and/or composted after being thoroughly dried, although this poses some serious risks. To avoid further growth, foliage, seeds, and roots should never be chipped or composted even after drying. Trunks and branches can be chipped or composted with caution after drying, if the plant is of a type that cannot vegetatively reproduce (resprout from rhizomes or fragments). Woody vines should never be composted or chipped.
I do not recommend chipping or composting any part of any invasive species, because it is easy to miss a seed in the mix, or not fully dry your debris. Invasive species are aggressive, adaptable, and not nutritionally beneficial to Vineyard soil. They don’t hold much value for compost and can amplify an infestation when fragmented.
Herbaceous Plants
Herbaceous plants are non-woody vascular species. The following invasive species are herbaceous; high risk species are marked with an asterisk:
- Aegopodium podagraria (Bishop’s goutweed; bishop’s weed; goutweed)*
- Alliaria petiolata (Garlic mustard)
- Artemisia vulgaris (Mugwort)*
- Centaurea stoebe (Spotted knapweed)*
- Cynanchum louiseae (Black swallow-wort, Louise’s swallow-wort)*
- Fallopia japonica (Japanese knotweed; Japanese or Mexican Bamboo)*
- Ficaria verna (Lesser celandine; fig buttercup)*
- Hesperis matronalis (Dame’s rocket)
- Iris pseudacorus (Yellow iris)*
- Lythrum salicaria (Purple loosestrife)*
- Microstegium vimineum (Japanese stilt grass; Nepalese browntop)*
- Miscanthus sinensis (Chinese silvergrass; Eulalia)*
- Phragmites australis (Common reed)*
- Polygonum perfoliatum (Mile-a-minute vine or weed; Asiatic tearthumb)*
Disposal Methods
Solarizing and Brush Pile or Landfill
The safest way to handle invasive herbaceous plants is to solarize any debris in black plastic for two weeks or more, and dispose of it with your garbage. Many herbaceous species, notably goutweed, knotweeds, and Lesser celandine, can regrow from small fragments that can be transported long distances. Any species that reproduces via stolons, shoots, rhizomes, bulbs, or tubers should be considered high risk. These high risk species should never be composted or added to a brush pile.
Some species can be added to a brush pile after solarization, but many risk re-rooting or spreading even after solarizing. View the list above to see high risk species, marked with an asterisk. Layer a tarp below your brush pile and on top of your brush pile to avoid re-rooting. Always bag and dispose of seeds, fruits, and roots as trash.
Drying and Brush Pile
As with woody species, herbaceous plants that have not set seed can be left on an impervious surface like a tarp, pavement, a rock, or wooden pallet to air dry in the sun for at least two weeks. Once the material is fully dead and dried, some species can be added to a brush pile. Layer a tarp below your brush pile and on top of your brush pile to avoid re-rooting and further spread.
Species like grasses or plants that reproduce with rhizomes should never be added to a brush pile. View the list above to see high risk species, marked with an asterisk. These species should be bagged, solarized, and sent to a landfill as trash. All flowers, seeds, or fruits should always be bagged and solarized.
Special Considerations
Do not compost herbaceous debris as there are many species that reproduce vegetatively and will resprout in compost. Never compost or chip invasive grasses; either dry and leave on site or bag and treat as trash. Some species that aggressively reproduce from leaves or fragments should also not be added to brush piles because they may be able to re-root and continue growing even after treatment. If you plan on adding herbaceous species to a brush pile, consider layering a tarp underneath and on top.
Setting Your Expectations
As many of you know by now, invasive species control is never a one-and-done situation. Both the removal and disposal sites should be monitored carefully for signs of regrowth so you can steward them accordingly.
Disturbance caused by invasive removal creates ideal conditions for other invasive plants to take root. It’s important to manage your removal site like a restoration area to encourage native species rather than another infestation. For more information and post-removal stewardship, check out my blog post on encouraging native regrowth after invasive control work.
