Virtuous Perennials

I like articles in which noted horticulturists go out on a limb to name their favorite plants. When accomplished gardeners like Pamela Harper, Rich Darke or Christopher Lloyd find extraordinary virtue in a particular perennial, I pay attention.

Their favorites don't always become my favorites, but I never regret trying them. My garden is a zone colder than Rick Darke's, after all, and two zones removed from Pamela Harper's. Christopher Lloyd and I might as well cultivate plots on separate planets, so different is western Pennsylvania clay from Great Britain's loam.

Still, I love growing plants judged "superior" by gardeners I respect. There's always the chance that I'll meet a new specimen that, hereafter, I won't be able to live without.

Geranium cantabirgiense x 'St. Ola' tops my list of perennials I couldn't garden without. Does that make it a favorite of mine? I think so, at least one of them. 'St. Ola' doesn't have the biggest flowers in the garden, nor the most spectacular leaves. But overall, it's as near-perfect as a perennial can be.

Low mounds of beautiful ruffled green leaves spread slowly to cover the ground. In the front of a border, as a groundcover on a slope, or in the rock garden, 'St. Ola's' growth rate is steady but never scary. She's polite and won't surprise you with unwelcome advances, such as underground runners popping up where they're not wanted.

In autumn, the handsome foliage bleeds from green to crimson to burgundy, and lasts all winter in that state of suspended animation. By spring, 'St. Ola' looks slightly bedraggled, but she's done a good job of protecting the soil from erosion and awaits early renewal at the hand of spring.

When they arrive, the pale pink blossoms stand well above the foliage. And they last a full month in exquisite form--longer than most perennials and more decorative than other groundcovers. When they're spent, the flower stalks yield to a gentle tug, and a large mound is quickly groomed.

Though I've never had occasion to try it, others report that Geranium cantabrigiense is "mowable." Once a year, a lawn mower set at the highest setting won't ruin it, but rejuvenate it.

For those who live in deer territory, a favorite plant should be deer-resistant. Hellebores certainly fall into that category.

I grow several varieties: the Christmas rose (Helleborus niger), Corsican hellebore (H. argutifolius) and stinking hellebore (H. foetidus). But none is as useful, or as necessary to my well-being, as the Lenten rose (H. orientalis ). It's also the easiest to grow.

In shade or full sun, through monsoon or drought, Lenten rose is both durable and classy. Its blooms are among the first of the new season, purple and white jewels, many with distinctive "freckles" on the petals. The faded green bracts hang on for months, giving plants the appearance of being in bloom long into summer.

Lenten rose makes a sizeable clump, and, with patience, an excellent evergreen groundcover. Growth rate is slow, but, after a while, seedlings appear at the base of mature plants. By lifting these seedlings in spring and spacing them 18 to 24 inches apart in a prepared bed, a gardener can gradually expand a planting at no cost.

A favorite perennial should be as handsome in leaf as it is in bloom. In that category, I nominate Sedum 'Matrona'. Superior to 'Autumn Joy' in every way, 'Matrona's' blue-gray leaves are thicker and more succulent, almost cactus-like in their appeal. Though plants reach just 24 inches high, they look larger when massed. Perhaps it's the visual weight of their remarkable foliage.

A perfect companion to Sedum 'Matrona' is 'Shenandoah' switch grass (Panicum virgatum 'Shenandoah'), whose feathery red foliage complements the sedum's thick maroon stems and light pink blossoms, especially nice in the clear September sunshine.

Bloom time has a lot to do with my extreme fondness for Chelone lyonii. I simply love its intense rose-colored blossoms and its unwavering willingness to help out in August, traditionally a difficult month for this western Pennsylvania gardener.

Glossy green leaves are pest-free and sturdy--clumps never need staking. To extend blooming, I pinch some of the stems each spring. Pinched plants stay slightly shorter and bushier than un-pinched plants. They also bloom a week or two later, so I can enjoy the colorful blossoms into September.

Usefulness should count for something, and for that reason alone Epimedium, or barrenwort, makes my list of all-time favorites. I find myself recommending it more frequently than any other shade-loving perennial.

To cover the ground or edge a path, rely on epimedium. It tolerates dry shade better than any other deciduous perennial, except perhaps Symphytum grandiflorum . But its foliage and flowers are so superior that it's really no contest between the two.

Most vigorous of the epimediums are the varieties 'Sulphureum' and 'Frohnleiten', both yellow blossoms, followed by the red- and white-flowered forms.

(Lindsay Bond Totten, a horticulturist, writes about gardening for Scripps Howard News Service.)