The Need for Native Plants

Why, how, and where to make the switch to native species

“What we do in our yards matters. It matters a lot,” says Cheryl Gross, president of Plant It Wild, a nonprofit organization based in Benzie and Manistee counties fostering the appreciation, understanding, and use of plants native to Michigan.

Gross explains that not only are native plants lower maintenance—requiring less water, fertilizer, and pesticides than non-natives because they are adapted to northern Michigan’s climate, soil types, and pests—but they are also ecologically beneficial, supporting hundreds of species of native insects, birds, and other animals with which they have coevolved. “It’s all about the food web,” says Gross. “That food web is what I push every day.”

From Bugs to Birds
In fact, Gross says that she actually likes seeing chewed leaves on her plants, because that’s how she knows that her plants are providing nourishment to native herbivores. Some of those herbivores, particularly caterpillars, are very specific in their diets, often only having one species of host plant that they feed on before metamorphosing. This specificity in the larval stage often makes well-intentioned pollinator gardens food sources for adult insects only, which usually have a more varied diet.

“Monarchs are a good example,” explains Shelly Stusick at Northwest Michigan Invasive Species Network (ISN). “The adults can drink nectar from hundreds of flower species, but monarchs will die out if they don’t have milkweed,” the sole source of food for the caterpillars.

This paradigm, however, is not unique to monarchs. “This is the case for much less glamorous species,” says Stusick. Native oaks, for example, can support more than 500 moth and butterfly species, whereas non-native trees likely will not support any.

Moreover, that close relationship between insects and plants doesn’t just affect the lowest levels of the food web; according to research from entomologist Doug Tallamy of the University of Delaware, a pair of black-capped chickadees needs a whopping 6,000 to 9,000 caterpillars just to raise one clutch of offspring. They’re much more likely to find caterpillars in those numbers in an area dominated by native plants.

The Invaders
Where native species aren’t planted, invasive species—those that are not native to northern Michigan and that cause harm to the environment, economy, or human health—can thrive. While there are close to 200 invasive plants in northern Michigan, below are three common species from ISN’s Top 12 List, invasives that are established in the region and that pose a higher risk of ecological harm than other invasive plants.

Garlic Mustard: Invading forest edges and shaded roadsides, garlic mustard spends its first growing season as a small rosette, sending up a 2- to 3-foot stem topped by clusters of small, white flowers the following year. True to its name, every part of the plant smells like garlic when crushed. To remove it, hand-pull it in the early spring before the plants set seed, bag it, and send it to the landfill or drop it off at one of ISN’s designated garlic mustard dumpsters. Alternatively, make pesto from the garlicky, edible greens.

Japanese Barberry: A spiny shrub with arching branches, spoon-shaped leaves, and bright red berries that appear in mid-summer, this plant is severely invasive and often planted in yards as an ornamental. The good news: It has a shallow root system, meaning it can easily be pulled or dug out. Removing the plant before fruit set is crucial to avoid spreading seeds during the removal process, so aim for spring. A weed wrench and protective gloves make the task easier.

Purple Loosestrife: This plant is best identified by its spikes of striking purple flowers that bloom in roadside ditches, in wetlands, and along shorelines from July through September. Remove purple loosestrife as soon as it’s observed, as it’s difficult to eradicate once established. Pulling very small infestations can be successful over a few years, as long as all parts of the plant are removed.

Also on ISN’s Top 12 list are baby’s breath, blue lyme grass, glossy and common buckthorn, Callery/Bradford/Cleveland pear, invasive honeysuckles, knotweeds, invasive bittersweet, invasive phragmites, and tree of heaven.

Plant This, Not That
For Stusick, managing invasive species and planting native species go hand in hand. “You can’t tell people what not to plant without telling them what to replace it with,” she says.

As for what to plant, Gross stresses the importance of knowing your soil, though she says that because most of northern Michigan’s soil is quite sandy, the following swaps should work in most places.

Gross recommends replacing Japanese barberry with serviceberry, a native shrub that blooms in the early spring, providing an early nectar source for pollinators. Stusick likes trading out Japanese barberry for common spicebush, a native shrub that plays host to swallowtail butterflies.

For trees, Gross says to replace non-native Colorado blue spruce with natives like white spruce, northern white cedar, or balsam fir, and replacing Norway maples with native sugar or red maples. (Bonus: The latter two maples are much better for tapping to make your own maple syrup!)

Instead of periwinkle as a ground cover, use wild strawberry, native violets, or Potentilla simplex (a creeping type of cinquefoil with delicate yellow flowers), says Gross.

To ensure that native plants are as beneficial as possible, Gross recommends avoiding cultivars, which have been bred to alter physical characteristics like bloom color or scent. She feels that there hasn’t been enough research on how these changes affect the animals that rely on these plants, though there is burgeoning evidence for some negative impacts; for example, altering flowers from a single layer of petals to a double blossom makes the flower less accessible to many pollinators.

Need more ideas? For those interested in learning more about converting a lawn full of non-natives and invasives into one teeming with beautiful and beneficial natives, Plant it Wild offers programs May through September on a wide array of topics, like garden layering, fall transplanting, and field trips to local natural areas and native plant gardens. “We try to be the educational resource,” says Gross.

To learn more, visit plantitwild.net.

Where to Get Your Native Plants Fix
The Go Beyond Beauty (GBB) program at Northwest Michigan Invasive Species Network was designed specifically to connect property owners and gardeners looking for native plants with nurseries, retailers, and landscapers who sell them. The program is, as Stusick says, for “anyone with a garden or anyone who’s making decisions about gardens.”

To make finding native plant retailers easy for consumers, GBB has amassed eight participating nurseries and garden centers in their four-county service area and beyond that have committed to both offering a selection of native plants and to banning the sale of harmful invasive ornamental plants.

Those suppliers include Bioconcentric Farms in Empire, Birdsfoot Native Nursery in South Boardman, Black Cap Farm in Onekama, Cyman Gardens in Bellaire, Garden Goods in Traverse City, Greystone Gardens in Honor, Misty Ridge Greenhouse in Mesick, and Pine Hill in Traverse City and Kewadin.

Black Cap Farm and Birdsfoot Native Nursery sell exclusively natives, with Birdsfoot Native Nursery even focusing specifically on propagating Michigan genotypes so the plants are particularly adapted to the state’s conditions.

Head to habitatmatters.org/go-beyond-beauty to explore more.

 

(Photos courtesy of Northwest Michigan Invasive Species Network)

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