Peony eyes sit just under the soil in autumn, pink and swollen, waiting out the cold that will make them flower. In Delaware, plant those roots in September or October, once the summer heat lets go.
When to Plant Peonies in Delaware
Plant or divide peonies in Delaware from September through October, so the roots settle in while the soil is still workable and well before winter. The year then follows a clear seasonal rhythm.
- In September and October, set bare roots or divisions in the ground, keeping the pink eyes close to the soil surface, because a peony planted too deep may bloom poorly or not come up at all.
- Through winter, the roots rest in the cold, and that rest is what triggers flowering the following spring.
- In spring, red shoots push up, and in the warmest parts the first flowers can open from mid-April.
- In May, the main bloom arrives, and June can still bring late flowers.
- In November and December, the foliage yellows and dies back, and that is when herbaceous plants get cut down.
For a reference city in Delaware, the last spring frost falls between April 3 and April 14, and the first fall frost between October 26 and November 7. Across Delaware, USDA hardiness zones range from 7a to 8a. Suburban and rural yards often freeze later in spring and earlier in fall than that city, so check your own county before you buy roots. A newly planted peony may also skip its first spring bloom.
Delaware — the year and the numbers
- State
- Delaware
- USDA zones
- 7a-8a
- Last spring frost
- April 3 to April 14
- First fall frost
- October 26 to November 7
- Annual rain
- 45 in
- Lawn zone
- cool-season
- Source
- NOAA NCEI 1991-2020 Climate Normals, 32F freeze probabilities · Wilmington
Which Peonies Grow Best in Delaware?
Peonies do well in Delaware, though the state sits toward the milder end of what they like. They need a stretch of winter cold to flower, and they may flower poorly in mild-winter climates.
Herbaceous and intersectional types are the easiest to grow and share the same culture: they die back to the ground each fall and send up new growth in spring.
| Peony type | How it does in Delaware | Why |
|---|---|---|
| Herbaceous | Reliable, blooms in May | Dies back each fall and rests through the winter cold |
| Intersectional (Itoh) | Reliable, easy to grow | Same yearly cycle as herbaceous, cut back after the foliage dies |
Tree peonies keep their woody stems all year and are never cut back, so they need different handling from the types above. In a mild-winter climate, any peony may flower more sparingly.
When to Plant, Cut Back and Feed Peonies in Delaware
Planting and cutting back follow a clear seasonal rhythm.
| Task | Best timing in Delaware | Why then |
|---|---|---|
| Plant or divide | September through October | Roots establish before the ground turns cold |
| Cut back herbaceous peonies | November through December, or March and April | The foliage has died back after frost, and early spring is the other window |
| Feed | Ask for local guidance | Feeding needs vary with garden conditions |
| Enjoy the bloom | May, sometimes April or June | Warm spells move flowering earlier or later |
Cut herbaceous peonies to the ground once the leaves have browned. Tree peonies skip this job entirely.
How Peony Planting Dates Change Across Delaware
Delaware is small, but local conditions can still nudge the peony calendar.
- New Castle County: Local conditions can shift the season relative to other parts of Delaware.
- Kent County: The September-to-October planting window applies here as it does across Delaware.
- In the warmest parts: Flowering here can start in mid-April.
Whichever county you garden in, plant or divide in September or October and watch your yard for seasonal shifts.
Where to Get Peony Advice in Delaware
University of Delaware Cooperative Extension answers plant questions for the whole state, and each county has its own office with local staff.
- Your county extension office can help diagnose a peony that will not bloom or shows spots on its leaves, so bring a clipping.
- A soil test through the office can help before planting.
- Master gardener volunteers can answer questions about varieties and spacing at local events.
Common Questions
Can You Move a Peony in Spring in Delaware?
September and October are the recommended months for moving a peony.
Why Is a Delaware Peony Growing Leaves but No Flowers?
Look at planting depth and sunlight together. Eyes buried deep in the soil are a common reason for foliage without buds.
Do Peonies Need Winter Protection in Delaware?
Herbaceous peonies need a cold winter rest to flower.