Best Peonies for Ontario

Peonies reward patience: the clump you set in the ground in fall comes back thicker and heavier every spring. In Ontario, the best choices are the herbaceous and intersectional types, with tree peonies as a woody alternative for gardeners who want something different.

Best Peonies to Grow in Ontario

Herbaceous and intersectional peonies are the easiest to grow in Ontario, and tree peonies and woodland peonies also have a place in the home landscape. Peonies need a cold winter rest to flower well, and Toronto sits in Canadian hardiness zone 7a, a rating that comes from a different system than the USDA’s and does not convert to it. Ontario winters give the plants the chill they need.

Herbaceous Peonies

The classic garden peony dies back to the ground each fall and sends up fresh growth in spring, so its yearly routine is straightforward. Plant or divide it in September, or October at the latest, so the roots settle in before winter.

Once frost has blackened the foliage, cut the stems back in October or November, down to within a couple of inches of the soil.

Intersectional Peonies

Also sold as Itoh peonies, these are hybrids of the garden peony and the tree peony. They share the herbaceous peony’s routine: they die back each fall and return in spring, so the care is the same as for a garden peony.

Choose this type if you want the look of a hybrid without a change in routine. Fall planting and fall cutback work just as they do for herbaceous plants.

Tree Peonies

Despite the name, a tree peony is a woody shrub. It goes dormant over winter, then pushes new growth each spring from stems that stay standing through the cold months.

Because those woody stems carry the plant from year to year, the pruning habits you use on a garden peony do not apply here. Give the shrub room to build its framework over the seasons.

Woodland Peonies

Paeonia japonica is the woodland peony, which is grown in home landscapes. It is a smaller, quieter plant than the garden peony and suits gardeners who want variety beyond the usual big blooms.

Plant it in fall like the other types, and treat it as a specialty choice rather than your main planting.

How to Choose a Peony for an Ontario Garden

The right peony depends less on a long list of cultivars than on how much work you want to do and what shape you want in the bed. Start with the type, then pick a color and form you like.

Every type listed here is planted in September or October, which gives the roots time to establish before the ground freezes.

Woodland peonies suit gardeners who already have the main types and want something a little different in the landscape.

Which Peonies Suit Different Parts of Ontario

Ontario is big, and the choice of peony stays the same across it, but the timing and the reliability of spring growth shift from south to north.

• Toronto and the Greater Toronto Area: The average last spring frost falls on April 30, which is only the midpoint of a window, so frost can still arrive after that date in one year out of two. Herbaceous and intersectional peonies are comfortable here, and tree peonies are worth a try if you want a shrub.
• Northern Ontario: Spring frost runs weeks behind the Toronto date, so new growth starts later and may be nipped by a late freeze. Confirm planting timing locally.

Upland districts elsewhere in the province also run behind the Toronto date, so expect later spring growth there.

Peony Buying Mistakes to Avoid in Ontario

Planting Too Deep

A peony set too deep may bloom poorly or fail to come up at all.

Keep the eyes, the small buds on the root, near the soil surface when you plant or divide in September or October.

Cutting a Tree Peony to the Ground

Gardeners used to herbaceous peonies often cut every peony back after frost. A tree peony keeps its woody stems, and cutting them away removes the framework that carries the plant into spring.

Leave the stems alone, and save the cutback for the herbaceous and intersectional types.

Planting Too Late in Fall

Peonies planted after October have little time to get established before winter. A rushed planting can leave the roots weaker going into the cold.

Aim for September, or October at the latest, and give divisions the same window. Skip the spring rush at the garden centre if you can wait for fall.

Where to Get Peony Advice in Ontario

Ontario has no local extension page on peony timing, so the dates here follow the nearest comparable climate. Confirm local timing with a nearby garden centre, a garden society or the province’s gardening groups. For broader guidance, Ontario Agriculture and Food is the provincial starting point.

• A local garden centre can tell you which peony types and cultivars have done well in your area.
• A garden society or master gardener group can answer questions on timing and siting.

Common Questions

When Do Peonies Bloom in Ontario?

Peonies bloom from May into June, depending on the type and cultivar. Herbaceous and intersectional types bloom as the season warms, and tree peonies flower on their woody stems.

Will a New Peony Bloom the First Spring?

A newly planted or transplanted peony may not bloom the first spring. Be patient while the plant puts its energy into roots.

Can You Cut Back Peonies in Spring in Ontario?

Yes, for herbaceous peonies. Fall is the usual time, in October or November after frost, but cutting back in March or April also works. Tree peonies are never cut back to the ground.