When it comes to native vs. invasive plants, you fall into one of three categories:
- You care.
- You don’t care.
- You don’t know.
Lump me in the last category, where I assume the vast majority of green-lovers reside.
Making the distinction between the two comes down to the old real estate saw: It’s all about location, location, location.
A plant that is local and native in one area may be invasive in another. It’s that simple.
Determining what is native is relatively simple: You ask someone who knows or check the Google. Be prepared for surprises.
I have loved English ivy since my half-English mother-in-law introduced me to it back in he 1970s. It’s low-lying, lush and green summer and winter. It spreads into other stuff but you can mow it out.
Turns out that English ivy ranks No. 10 on the most wanted invasive species list for Fairfax County.
The problem is that it’s a spreader and a smotherer. It kills trees by growing corkscrew-like up the trunk and squeezing the life out of them. So while I had hoped to encourage my English ivy to help me with erosion, I will be relying on Golden ragwort as a native alternative.
I’ll also be pulling up all of the Japanese stiltweed, which serves as my largest green erosion control ally. It ranked No. 4 on the most wanted list. (Kudzu was No. 1, but I figure everyone knows that.)
Other invasive species in my yard include Periwinkle and the Bradford Pear.
I just planted three native species for erosion control that I bought very inexpensively from the Potowmack Chapter of the Virginia Native Plant Society, which sells native plants at Green Spring once a month.
- Golden ragwort (Packera aurea)
- Lyre-leafed sage (Salvia lyrata)
- Robin’s plantain (Erigeron pulchellus)
I have high hopes that this trio will spread quickly, attract pollinators and generally play well with others.
Invasive plant removal is not a one-shot deal.
In fact, some invasives have seeds that can lie in the ground 5-7 years before sprouting. So you keep going at them. You pull them where you can, and cut them where you can’t. If you have to, you spray.
- An invasive plant is one that is not native to the area in which it evolved.
- Forty-two percent (42%) of threatened or endangered species are threatened by invasives.
- Invasives are characterized by their:
- Fast growth and spread
- Prolific seed production
- Easy dispersal
- Expense to remove
- Many invasives are very beautiful, which is why we plant or tolerate them. I am told that native species are just as beautiful; I just need to learn more about them.
- Most invasives are not accidents of nature. They are introduced to areas beyond their native habitat for a reason. A lot of our invasives came from Japan and China in the 1800s, when plant lovers were always looking for something new (i.e., not local) and exotic (i.e., non-native). A surprising number were thought to be solutions to problems, like erosion. They just became a bigger problem.
- The “problem” with invasives is that they have no native control outside their natural habitat. They destroy biodiversity, or the variety of life in the world or in a particular habitat or ecosystem. They offer nothing good for insects, birds or animals to eat.
- Not convinced? Deer won’t even eat most of the plants on our local most wanted dead list.
Here are three places to start if you want to determine whether you have invasive species on your property and identify native plant alternatives.
Invasive Plant Species of Virginia (http://www.dcr.virginia.gov/natural-heritage/invspinfo) – Web site.
Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeake Bay Watershed (https://www.nps.gov/plants/pubs/chesapeake/pdf/chesapeakenatives.pdf) – Free PDF book.
Plant Invaders of the Mid-Atlantic Natural Areas, 4th ed. (https://www.nps.gov/plants/alien/pubs/midatlantic/) – Free online book.
The gazebo at Green Spring Gardens.
Read the handbook chapter on Plant Propagation, or dirty little plant sex secrets.