Tips for the Ecological Gardener…
Thinking about replacing invasive species?
The native coral honeysuckle vine (Lonicera sempervirens) glittering after an evening rain. A sought after plant by the native Ruby-throated hummingbird.
Remember to dream big…
Let's talk about why and how...
The threat of introduced invasive plant species on native ecosystems is substantial and once you start getting into the weeds of it (sorry for the pun) it can get a little overwhelming. Notably for many homeowners I talk with, as of 2024 it is illegal to sell Japanese barberry (Berberis thunbergii) or Burning bush - also known as Winged euonymus, (Euonymus alatus) in the Commonwealth.
These plants, quite common in many home gardens, are recognized as part of the growing list of invasive plant species kept by the Pennsylvania Department of Conservation and Natural Resources (DCNR) as well as the PA Department of Agriculture's noxious weed list.
As these plants escape into natural areas, they proliferate exponentially, displacing native plant species and thus eliminating critical food sources for native wildlife. The can disrupt carbon cycles, forest succession, the list goes on. There a number of excellent resources to learn more about both the threats of invasive plant species and techniques for removal- check out our Educational Resources Page to delve deeper on this topic.
The invasive species, burning bush (Euonymus alatus), banned for sale in Pennsylvania
What I want to explore with you here however, is answering the question: after I've identified a plant in my garden that is non-native and invasive, and I would like to replace it with a native plant to support native wildlife, and bring some unique beauty into my gardens..
What do I plant next?
For reference, here are some common invasive species folks may have cultivated in their gardens from the DCNR list (refer to the list though, I can't fit them all here). Apps like Seek, iNaturalist, PlantNet, & PictureThis can help confirm identification.
Trees:
- Mimosa- Albizia julibrissin
- Norway maple - Acer platanoides
- Tree of heaven- Ailanthus altissima
Shrubs:
- Asian shrub honeysuckles- Lonicera maackii and others
- Butterfly bush - Buddleja davidii
- Japanese barberry - Berberis thunbergii
- Linden viburnum- Viburnum dilatatum
- Privet - Ligustrum sp.
- Winged euonymus or burning bush - Euonymus alatus
Vines:
- Bittersweet - Celastrus orbiculatus
- English ivy - Hedera helix
- Periwinkle or vinca - Vinca minor and Vinca major
- Wisteria - Wisteria sinensis and Wisteria floribunda
Grasses:
- Chinese Silver Hair Grass - Miscanthus sinensis
Flowering perennials
- Dame's rocket - Hesperis matronalis
- Purple loosestrife - Lythrum salicaria
- Japanese pachysandra - Pachysandra terminalis
The invasive species (top to bottom): Japanese barberry (Berberis thunbergii), English ivy (Hedera helix), Chinese silver hair grass (Miscanthus sinensis)
The 1-1 replacement model
If you google "native replacement for __________ in my region" you'll generally find a straightforward list of plants.
For example: If you have a bittersweet vine growing on an arbor in your yard, Google will quickly tell you that you can replace it with a native Coral honeysuckle vine (the hummingbirds will thank you as will the rest of us). Boom.
Sometimes though the 1-1 replacement model can get a little more complicated... If you Google "native alternatives to burning bush" and you'll find a lot of suggestions.. However, you have to keep in mind that burning bush can grow as an understory plant in woodlands and it can live in a parking lot median.. which iteration of burning bush are you trying to replace?
For example if you're talking about an open understory or partially shaded spot, you could try to plant the native Euonymus - Euonymus americanus - also known as the American strawberry bush. But if you've got a dry location in full sun? Keep looking.
Keep in mind.. Gardens are complex systems..
What I am getting at with the Euonymus example is that there are a lot of variables that affect what "works" in your garden, and its important to take time to consider them, whether hiring a professional or working on your own.
An opening in the garden is an opportunity to think outside of the box
When discussing what to do with a newly open space after committing to or removing an introduced or invasive species, start by taking a step back. It's important to acknowledge that most of the elements in our landscape - and we're not just talking about the plants here - are inherited from decisions that were made either by our past selves 5, 10, 15, 30 years ago or from past homeowners.
Those decisions interact with many factors - aesthetic preferences can change when we see examples of other gardens; our health can affect how active we can be in the garden; sometimes choices made on adjacent properties by neighbors, municipalities or developers can cause shifts in our spaces that require attention. Trees mature, casting shade in new places. Regardless of the factors influencing the current state of the garden, circumstances change and that is a wonderful and exciting thing! It is also something to be attentive to.
Altering elements in our landscapes, such as removing invasive plant species, opens up space to consider a new path both in terms of the ecological value of our landscapes and the utility they provide for us and our friends and families.
Consider- could that thicket of privet or mass of burning bush get planted with low growing native wildflowers and ferns and become a space to set a bench for your morning coffee, you've always been wishing for? That would be charting a very different path than replacing them with another medium sized mounding shrub using the 1-1 replacement model.
Turf grass and lawns can become wildflower meadows if we don't need all that space anymore; maybe that ground out Norway maple stump wants to be the start of a rain garden system.
The solutions are numerous when you start asking the "What if" questions and "What if" questions start to arise quickly when folks begin to transition invasive and introduced plants in the garden to native ones. It's important to seek information and move slowly, quick fixes sometimes will be the forest for the trees.
And so this is why my answer to the question of "what do I replace '_______' with?"
Generally is: "It depends..."
Because these answers depend on you!
Your landscape is unique and its development should be tailored to how you live, or would like to live, with the natural world!
If you'd like help transitioning a part or all of your garden to a native, functional, beautiful landscape please reach out, we're here to talk and support projects of any size.
Invasive species, including English Ivy, & other non-native vegetation removed from a clients property for a native garden installation
THANKS FOR READING