Sunday, September 18, 2016

Roadsides: Trash or Treasure?

I think about roadsides a lot this time of year and there are several reasons why. 1) Sunny roadsides with good native plant populations really shine this time of year. 2) Roadsides that got whacked by utility contractors are really ugly this time of year. 3) Roadsides that are overgrown with invasive plants are at their tangled peak by now. I wonder what other people think. Do they look at roadsides and see trash or do they see treasure? The answer, I think, lies in how much they know about what they see.

You see roadsides can be full of trash or treasure. It depends on how they are treated, and humans play an important role in what’s there or what’s missing. What would make a roadside be considered trash vs. treasure?

You probably won’t be surprised to learn that the distinction lies in the type of plants that reside there. A roadside with native plants tips toward the treasure end of the spectrum. How far along the spectrum it is depends on what kind of native plants are there. A roadside rich in a diverse mix of native plants is desirable compared to one that is composed of just a few types. For example, a roadside composed of all one type of tree (for example, pine trees) won’t support as many insects and birds as one with a dozen different plants. If that diverse mix includes flowering plants across several seasons, the treasure score goes even higher.

Small residential area with part lawn and part wild roadside
A good roadside is a sunny strip that might be bordered by a bit of a tree line with 2 or more different kinds of native trees and shrubs. It would include some rambunctious annuals, some biennials and a few perennials as well. In my area that might be daisy fleabane (Erigeron), black-eyed Susans (Rudbeckia), thistles (Cirsium), goldenrod (Solidago), thoroughwort (Eupatorium), milkweeds (Asclepias), ironweed (Vernonia), sunflower (Helianthus), and native grasses. The tree line has sweetgum, oak, pine, sassafras, sourwood, tuliptree, muscadine, and maples.

A wet ditch roadside might have wingstem (Verbesina) and ironweed (Vernonia)

At the trash end of the spectrum is the roadside choked with non-native plants. The very worse (at least to humans) might be one smothered in kudzu. However, it doesn’t even have to look that obvious to be a place that offers very little sustenance to our native insects and birds. (A roadside composed of crape myrtles and Bermuda grass would do the trick, and surprisingly, these types of manicured roadsides are being installed more often around interstate exchanges – imagine the maintenance!) Usually, roadsides are havens for non-native plant seeds to settle and take root, free of most human intervention to dislodge them (until they get in the way of a utility).

Roadside in 2014 with pears moving in; 2 years later it is thick as a jungle
A trashy roadside has non-native grass, lespedeza, mimosa, tree of heaven, princess tree, elaeagnus, privet, Queen Anne’s lace, non-native thistles, and vines like kudzu, Japanese honeysuckle, porcelainberry, and English ivy. It’s roadsides like this that give roadsides a bad name! They become overgrown with invasive plants, untended except by utility contractors and road crews anxious to get the job done and be gone (bush hogs are popular brush management tools in my area).

English ivy chokes both the trees and the ground

How can we have better roadsides? In general, I would recommend four concepts to foster more productive roadsides:

  • Protect roadsides that already provide good native plants
  • Manage roadsides for invasive plant removal and annual mowing and maintenance if needed
  • Create roadside habitat by seeding degraded areas with native seeds/plants
  • Educate people on why roadsides and edges can help local insects and birds if native plants are present
Imagine that road crews might be instructed to identify and remove the top 5-10 invasive woody plants rather than just hack them back (only to have them return with a renewed vigor). People could reseed disturbed areas with native seeds, instead of non-natives, and with plants chosen for low maintenance even while they support the local insects. People would use the power of the Internet to identify what plants are and decide to keep them or not!

So, are roadsides trash or treasure? The answer is both – for now. How long will that last, until all we have is trash? Let’s invest in developing more treasure. As more and more of our land turns to developed spaces, the roadsides are some of our last sources of food for insects, birds and small critters that live around us.

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