A tree peony carries blooms the size of a salad plate on bare, woody branches that were already standing the winter before. Those stems are the whole difference from the garden peonies most people know, and they change how you plant, prune and protect the shrub.
How Do Tree Peonies Differ From Herbaceous Peonies?
Tree peonies are woody shrubs whose stems survive winter, while herbaceous peonies die back to the ground each year. That one habit shapes everything else: planting depth, pruning and winter care all follow from it, and the details shift a little with the type of peony and your climate.
Mature plants grow into sizable multi-stemmed shrubs, and the woody branches usually hold the big flowers without staking. In Iowa, the blooms often reach 6 to 9 inches across.
The state selector shown just under this section takes you to the page for your own state, where the local timing lives.
From the almanac
Peonies in your state
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How to Grow a Tree Peony
Most of the work happens on planting day, because a tree peony is usually grafted and the depth of that graft decides how the plant roots in. After that, the care is light.
- In North Carolina, plant in the fall, when crowns are best planted or moved, so the roots settle before the next growing season.
- Set the graft union well below the surface, so that the upper section of the plant forms its own roots and grows true. Guidance differs by place: in Washington the graft goes about 4 to 5 inches down, in Connecticut 4 to 5 inches of soil should cover it, and in South Carolina an inch is enough.
- Bury a plant on its own rootstock less deeply, with the stem junction two inches below the soil surface in Pennsylvania, since there is no graft to bury.
- Check moisture below the top layer before watering, so that you do not soak roots that are still damp. Soil can look dry on top and stay moist well below the surface.
- Feed only when the soil needs phosphorus and potassium, so that the shrub does not receive nutrients it already has. In Kansas, a complete fertilizer such as 10-10-10 is applied at 2.5 pounds per 100 square feet, equal to 1 rounded teaspoon per square foot.
- Spread a light mulch over the roots for winter, so that the plant is cushioned against cold. Kansas gardeners do this even though tree peonies there are hardy to Zone 4.
Pruning differs sharply from herbaceous care. In North Carolina, prune only to shape the shrub and do not cut the stems to the ground in winter. Those woody stems carry next spring’s flower buds.
Tree Peony Care by Peony Type
Not every peony in the garden follows the same rules, and a woody plant sold next to herbaceous ones can fool you at the nursery. The type decides how deep the plant goes and what you do with it in winter.
Tree peonies are also called woody peonies, and Paeonia suffruticosa is a tree-peony species. In Arkansas it is described as a deciduous shrub up to 6 feet tall and wide, with flowers as much as 8 inches across in late April.
| Peony Type | What changes | Why it matters |
|---|---|---|
| Tree peony | Planted with the graft 4 to 6 inches below the surface in Pennsylvania, 6 inches in Washington | Deep grafts encourage the plant to grow its own roots |
| Tree peony | In North Carolina, stems stay through winter and are pruned only for shape | Cutting them down removes next year’s flower buds |
| Herbaceous peony | Cut to the ground in winter and planted shallower than a tree peony | Treating a woody plant this way harms it |
For you, the practical rule is to check the tag before you pick up the shears or the trowel. A plant labeled as a tree or woody peony goes deeper and keeps its stems, while a herbaceous one is the opposite on both counts.
Tree Peony Mistakes to Avoid
Planting the Graft Too Shallow
A graft left near the surface keeps the plant living on its rootstock rather than forming roots of its own. That can leave it weaker over the years. Bury the graft union at least 4 inches deep, as advised in Kansas, and use the shallower depth only where local guidance such as South Carolina’s says so.
Cutting Stems to the Ground
Gardeners used to herbaceous peonies often cut everything down in fall. On a tree peony, that removes the woody framework that carries the buds, and you may lose the next season’s bloom. Leave the stems standing and trim only to shape the shrub.
Watering by the Surface Alone
Topsoil dries fast and misleads. Watering because the top looks dry can leave roots too wet when the soil well below the surface is still moist. Push a finger or trowel into the ground first, and water only when it feels dry at that depth. Tree peonies are native to northern China, where annual rainfall is fairly modest.
Tree Peonies in Your State
The sign that triggers the work is the season turning to fall, when planting and moving make sense, and the dormant stems that need only shaping. Exact months differ across the country, so your own state’s page is the place to check.
- Look at your state’s page before planting day to see which fall months suit your area.
- Return to it before winter to time the mulching over the roots.
Common Questions
Do Tree Peonies Need Staking?
Rarely. In Indiana, mature plants are described as needing no stakes, because their woody branches hold the large flowers. Young plants may still lean a little while they build that framework.
How Tall Do Tree Peonies Get?
In Iowa, tree peonies reach about 3 to 5 feet tall. Leave room for a shrub that is nearly as wide as it is tall.
Can You Transplant a Tree Peony?
In North Carolina, fall is the time for transplanting tree peonies and planting new crowns. Replant at the same depth you would for a new plant, with the graft kept below the soil surface.
Sources : gurneys.com | gardeningknowhow.com