Invasive alien plants (a.k.a. aggressive plants from somewhere else) have been pillaging and plundering our landscape for a long time. Since humans began exploring new lands, plants have been traveling the world with them. Settlers would bring the plants they loved and were useful to them when they migrated. And, of course, not every plant that comes from somewhere else becomes invasive. Many of the annual and perennial plants sold at retailers in North America are not North American natives but plants from Europe and Asia. And, in fact, the majority of the food you eat, the food you want to eat locally, is not native to North America.
Not all non-native plants become invasive. The ones that do, though, have certain characteristics in common:
- Few or no predators/diseases
- Can reproduce quickly and through multiple methods
- Easily out-competes native plants
- Tolerates winter as a perennial plant or seeds can persist through freezing temperatures
I’m not going to get into naturalized plants or hybrid sterilized plants today. Rather, I’d like to discuss a specific invasive plants that impacts our landscape both economically and environmentally and then provide some excellent native alternatives.
Phragmites (Phragmites australis)
You’ve seen the strikingly attractive plumes of this plant decorating wetlands along highways and bi-ways. Also known as European common reed, phragmites most likely came to North America in the early 1800s in ballast water from ships (a common form of transport for non-native species). Spending its early days on the Atlantic coast, it has spread across North America in the last few hundred years.
North America does have its own native strain of phragmites (Phragmites australis americanus) but the non-native species has displaced many of the historical native stands. And it’s expensive: about $4.6 million across North America every year for a five-year study period was spent on just managing the problem.
How You Can Help
Phragmites was not brought here to ensure settlers could feel more at home. It was an accident and our native species are suffering great declines because of it. And while most counties have a good handle on their phragmites population, you can do your part by reporting stands of the stuff to your local authority. In Ontario we have the Invading Species Hotline, or you can submit a sighting online. Each region will have their own way of reporting such findings.
How Wildflower Farm Can Help
Wildflower Farm is here to offer you a native alternative to the plethora of non-native grasses available these days. Non-native grasses are always a risky decision: they produce so many seeds that aren’t easily controlled and there’s a good chance your small, planned plot will spread further than you had hoped in less time than you thought possible. Native ornamental grasses, on the other hand, are a great accent to any garden: they provide wildlife habitat, food for birds, and that winter interest us northern folk are always seeking. Some are even tall enough to provide privacy screens.
Check out the twelve native grass species we have at the Farm. I’m sure you’ll find one that will work for your space. Here’s a quick reference guide to help get you started:
I’ve also created a sort of pseudo-matrix that combines height and soil type. Plants typically grow shorter in clay since their roots can’t penetrate quite as easily. The following is just a guideline, however, and there are people who have big bluestem growing 7-8’ down in their clay soil. So, take this with a grain of salt but it may help you get started. The numbers after each species represent the potential height that species will reach growing in each type of media.
Finally, most native grasses, unlike many of the native flowers we sell, don’t need to experience winter to germinate. They don’t need cold, moist stratification, and they will do well to be planted in the spring (with the exception of sweetgrass).
Consider adding some native grasses to your garden plot or even just to accent your humble abode. They are stunning features and I’m glad I can see them still standing at Wildflower Farm despite the feet of snow we have already accumulated.