The University Record, February 5, 2001

Think spring: Hostas flexibility good fit for Michigan soils

By Joanne Nesbit
News and Information Services

Hostas in their prime in the courtyard garden at the School of Education. Photo by Marcia L. Ledford, U-M Photo Services
Hostas will grow in nearly any type of soil, including clay, sand or loam—in just about any base Michigan has to offer. And, depending on which variety is planted, hostas also can tolerate Michigan’s summers, whether hot and dry or hot and humid.

Ken Rapp, landscape architect, and Bill Kronberg, senior horticultural assistant, have designed plantings of hostas in various locations throughout the University’s Ann Arbor campus. In one garden, besides hostas, there are bleeding hearts, ferns, redbud trees, rhododendrons, evergreens, ground ivy and sparrows. While Rapp and Kronberg didn’t plan for the birds, their plantings, as well as the vines covering the surrounding buildings, have attracted numerous sparrows that flit from tree to hosta, to vine, to grass and back again.

Kronberg emphasizes that hostas are fairly easy to grow. “In fact,” he says, “some varieties can be happy in full sun in a parking lot. Some will grow well in clay, too, something we have challenges with in this part of the state.”

Yet there are some hosta varieties that bring with them their own problems. Kronberg says H. lancifolia seems to be especially appealing to rabbits, and one year, an entire hutch of bunnies lived off one of his plantings. But without rabbits, Kronberg says, “hostas can also provide a full summer of blooming if the right combinations are used.” One U-M garden area features 37 different types of hostas.

The variegated forms prefer partial shade, while the blue-leaved varieties need more shade to maintain their true blue coloring, Kronberg says. And while most varieties will tolerate less than ideal conditions, rich, organic soil and watering when needed are advised to bring out the best of the “big ones.”

Hostas neighbor well with small to medium trees, such as redbuds and dogwoods, with something like honey locust forming a central, taller canopy. In combination with these taller forms, hostas create a quiet, relaxing space. When paired with rhododendron—both prefer a cool, partially shaded site and hostas don’t mind the low pH required for healthy rhododendrons—both the textural and color contrast is pleasing. The two don’t compete spatially, Kronberg says, and “rhododendron provides much needed winter weight when the hostas go dormant in winter.”

Bleeding heart, Dicentra spectablis, also works well, because the foliage dies back in midsummer after its display, and the hosta fills in the gap without missing a step.

“Hostas can be texturally bold,” Kronberg says. They can be used creatively to provide ground, contrast, rhythm and movement, as well as sheer interest in the garden when used with any plant that shares its requirements. Hostas work well with astilbe; ferns; wildflowers such as Cornus canadensis (bunchberry), Erythonium americanum (yellow trout lilly); Sanguinaria canadensis (bloodroot); Hepatica acutiloba (sharp leaf hepatica); and Arisaema triphyllum (jack-in-the-pulpit); or low ground covers, such as Galium odoratum (sweet woodruff).

Hostas also work well with bulbs, because it conceals the ripening leaves of the interplanted bulb. Kronberg likes to use Allium aflatunense that rise between the leaves of blue halcyon hosta, golden sum and substance hosta and bloom just as the bleeding heart blooms are starting to dwindle.

While hostas can withstand some typical dry spells, watering at least once a week when they are first planted will help the plants get established. “Establishment is very important here in southeast Michigan where we can go weeks without rain,” Kronberg says. “Once established, though, hostas do real well in dry shade.” One really can’t go wrong when following the advice on the plant labels for spacing. “I planted ‘Abba Dabba Doo’ too close once and realized that a five-foot spread really meant a five-foot spread,” Kronberg says. “It’s really disappointing to see such a beautiful hosta like that cramped because it loses some of its majesty. It’s like being ‘dressed up and nowhere to grow.’”

Hostas can be used in many areas of a garden or landscape. “They have a sort of serene and calming disposition,” Kronberg says. “Though I’m surely not implying that they are boring. Just sort of, well, like manatees, maybe.”