It’s a little warmer, you’re planning your garden, and you remember that lovely silvery shrub—but wait. Before you head for the garden center, make sure you’re not choosing species that can threaten native Indiana plants, chase away bees and butterflies, and affect the ecosystem in a bad way, read on.
It’s true—the choices made for a backyard garden can have far-reaching consequences, both good and bad. “People have good intentions, but sometimes certain species of plants are brought in and are later discovered to be an invasive species, like the Japanese silver plant,” said Susan MiHalo, conservation coordinator at Nature Conservancy’s Southern Lake Michigan Rim Project Office in Merrillville, Ind. “Especially near a protected area, these invasive things start escaping (beyond the home garden).”
Dean Savarino at Dean’s Landscaping in Schererville, Ind., has seen it. “Invasive plants cause problems, so you do need to know what not to plant. The Chinese native grass or, any type of reed grasses, stay away from those—they’ll just take off.”
The Indiana Native Plant & Wildflower Society’s Web site explains, "The influx of exotic species, without their natural controls, can choke or shade out natural grasses.” That can even affect the food chain: “Some herbivores depend on as few as two types of plants.”
Hard to hold back
Think of the yard as potentially a wildlife corridor for butterflies, birds, bees and other creatures as they work their way to and from nearby remnant natural areas and managed natural areas, said MiHalo. They need Indiana’s native plants to survive, and Hoosiers need them to play a part in pollinating corn, producing honey, and helping support the overall ecosystem.
But it’s a struggle. “In this area, there are a lot of challenges for plants to survive, with roads, subdivisions, and so forth. Thirty percent of Indiana’s endangered species are in Lake County alone, so any help we can get from homeowners in improving biodiversity helps overcome all of these challenges,” said MiHalo.
Watch out for these
Some invasive species that crowd out essential native plants include many ornamentals that insects won’t use; shrubs like Japanese honeysuckle; and plants like dame’s rocket, garlic mustard, and Oriental bittersweet. MiHalo cautions against planting Japanese barberry, autumn olive, Asian honeysuckle, crown vetch, and for water gardens, water hyacinth. And avoid planting Lyme grass in the Dunes area: “Its ‘clumping’ root systems can change dune-building dynamics, impacting that habitat.”
And those wildflower seed packets? “‘Wildflower’ doesn’t mean ‘native,’” said MiHalo; many packets contain very invasive species like Dame’s rocket, so check the label.
Hits and misses
There are lots and lots of native plants to choose from. For sandy soils, says Beverly Stewart, manager at Reed’s Garden Center in Valparaiso, Ind., choose among marran grass, sawgrass, some sedges, any in the cedum family, and fescue. Boxwood and yews can help define an area. For general planting, Butch Zandstra, co-owner of Zandstra’s Greenhouse in Highland, Ind., is partial to butterfly weed, a type of milkweed that, not surprisingly, attracts butterflies.
Once the plants are bought, the biggest mistake home gardeners make, said Saverino at Deans Landscaping, is not understanding what kind of soil composition there is, or whether a particular plant can used for that area. “In this area, a lot of it is hard rock clay soil, especially in developed areas. Nearer the lake, it’s sandier and loamier. If you pick up a handful and it won’t hold tight in your hand, it’s loamy.” ln the Munster area, best choose plants that are more adaptable, like peonies, salvias and veronicas. At his website, deanslandscaping.com, there is a link to determine soil types.
Zandstra said new plants need attention for a couple of weeks, “a little water, a little care—they have such a small root system at first.” He advises watering all plants in the morning so the foliage can dry out during the day, lowering the chance for diseases to take hold.
A final note from MiHalo: “Please make sure not to harvest native plants in our managed natural areas.”
There is a season to plant, and thankfully, it’s just around the corner.