Herbaceous garden peonies boast all the attributes Canadian gardeners value: large, plentiful and easy to grow, many have sweetly fragrant flowers and are deer-resistant, drought-resistant and cast-iron hardy (to Zone 2). The plants are also substantial enough to be used on their own as a low hedge, with foliage that stays attractive for months (and makes great camouflage for ripening spring bulbs).
Peonies are tremendously long-lived. Many a gardener can point to a treasured unnamed specimen passed along from the garden of a parent, grandparent or friend.
Perhaps the only fault one can find with this paragon of perennials—besides the tendency for unstaked double-flower types to flop over in June thunderstorms—is that plants bloom just once a year, in early summer. However, by carefully considering the bloom times of peony species and cultivars, “The season can be extended over a seven-week period,” says peony grower Lindsay D’Aoust of La Pivoinerie D’Aoust in Hudson Heights, Quebec.
D’Aoust has helped Michael Denny, a professor of economics at the University of Toronto who collects peony bloom data from gardeners throughout North America, create a website called The Peony Bloom Time Project.
“If one wants a very long peony season, one has to select the early-blooming varieties,” says Denny. Over the seven-week period, which begins around May 15 to 20 in southern Ontario, the peak bloom time for most cultivars is in weeks 5 and 6, when almost two-thirds of the widely available cultivars bloom, including many of the popular double-flowered types (see bloom chart). “There are three weeks of possible bloom before Week 4 and only one week after Week 6,” he adds.
Peonies thrive in prime garden real estate. D’Aoust recommends planting them where they’ll get at least six hours of sunlight a day, a good distance from competing tree or shrub roots. They prefer rich, well-drained soil, so amend sandy soil with organic matter such as well-rotted manure or compost (add sand to clay soil if drainage is poor. Clay soil holds a lot of nutrients so the addition of compost is not necessary).
September through early October is the ideal time to plant, when roots can grow well while soil temperatures are still warm. Specialty growers offer the best selection of desirable cultivars. Peonies for fall planting come as thick, brown, tuberous roots with three to five eyes—the small, reddish buds near the top (if the roots are a little dry, soak them overnight in a bucket of water before planting).
You can also plant peonies in early spring, when nurseries tend to offer young, container-grown plants, provided the root ball remains undisturbed (the roots and soil are moved into the planting hole intact). Choose specimens with healthy, bushy foliage.
Site plants at least 90 centimetres away from neighbouring perennials. Dig a hole about 90 centimetres wide and 60 centimetres deep.
To plant peony roots, first partially backfill the hole with several shovel-fuls of soil, then pat it down and add water. Wait until the water has drained, then place the roots on top—eyes up, roots down—so the eyes are just five centimetres below ground level (planting too deeply results in fewer flowers). Backfill with remaining soil, firm gently and water well.
For container-grown specimens, plant them at the same depth they
were in their containers. (Note: the roots of container-grown peonies can be brittle, so ease them out of their pots gently.)
All that the newly planted clumps ask of the gardener is a little patience. As peony grower Allan Rogers, author of Peonies (Timber Press, 1995) puts it, “Remember the time-tested adage: The first year the peony sleeps, the second year it creeps and the third year it leaps.”
Top photo: 'Etincelanted' (week 5) by Tracy Cox