How (And When) To Plant Peonies | Horticulture.co.uk (2024)

PERENNIALS > PEONIES > PLANTING

By CHRIS LEE

Peonies are popular cottage garden perennials which can make a strong and long-lasting impact in your garden.

Herbaceous and intersectional peonies are usually purchased as bare-root divisions or as potted plants.

Bare root peonies are best planted in the late autumn, while those which come in pots are typically planted out in late spring.

To plant peonies:

1. Choose a suitable location for the peony you have chosen.
2. Make your planting hole – aiming for the same depth as the root ball but twice the width.
3. Place the plant in the hole and firm the soil around the new plant. Don’t plant too deep as this can result in poor flowering.
4. Water in well and repeat this until the plant is firmly established.
5. Mulch around the peony you have planted with organic matter.

Read on for a more detailed description of this process, and for expert tips to help ensure your peony gets off to the best possible start.

When To Plant Peonies

When you plant a new peony will depend on whether you have purchased bare root divisions or divided one of your own existing plants, or purchased a peony in a pot.

Carol Adelman, President of the Pacific Northwest Peony Society, suggests that you should usually plant bare-root peonies in late autumn, between October-November and plants sold in pots in late spring sometime in March-May.

1) Choose Where To Plant

Peonies should ideally be planted in a location with full sun and fertile soil which has been amended with plenty of organic matter.

They are unfussy about soil type, but will do best in locations which do not become waterlogged in winter or dry out excessively in summer, says Kate Blacker, owner of Little Budds Peony Farm.

“They prefer clay soil and don’t grow well on chalk or thin soils,” she says.

When choosing a suitable spot, it is important to remember that peonies can be large plants.

“The planting spot should have sunshine and good drainage,” says Carol.

“Allow 36 inches (91cm) spacing between each plant.This will look bare for the first year, but after three years, the space will probably be filled.”

However, space needs will obviously vary depending on the specific cultivar that you have chosen.

“Peonies prefer full sun and plenty of space,” says Kate, “we allow them 1mx1m.”

“Ours grow in an open field without support”.

That being said, some may find that larger peonies may benefit from staking.

You should consider adding support before planting to avoid potential disruption to the root system so that the stems can be tied to the support as the peony grows.

2) Make Your Planting Hole

When digging a planting hole, it is a good idea to make this hole much larger than the existing root system of the plant.

It should be the same depth as the root ball but should be around twice as wide.

“Mix tulip or daffodil bulb fertiliser into the bottom of the planting hole and cover it with a little soil,” says Carol.

“Lay the root flat on the ground with the eyes looking up at the sky.”

3) Plant The Peony

Place the peony into the planting hole.

Gently draw the soil back around the roots, firming it into place so that there are no air pockets.

“Herbaceous peony plants should be planted at a shallow depth, with only 1-2 inches of soil above the eyes,” advises Koen Hurtekant, the founder of The Peony Society.

“Shrubby peonies, on the other hand, should be planted deeper, 3-4 inches below the ground.”

If peonies are planted too deep, this can lead to poor flowering.

“Place them around 2-3 feet away from one another so that they have enough place to grow to maturity over the course of 4-5 years,” says Koen.

When planting bare-root peonies, Carol recommends you should cover the ‘eyes’ (which are the buds that will make the stems, leaves and flowers) with 2 inches of soil (5cm).

“Water it in. If you are in a very wet climate, level the soil after adding fertiliser, place the root there (on top of the soil) and pull dirt up from all sides to cover it, making a moat for the excess water to drain into.

“This will keep the root from rotting from standing water.”

4) Water In Well

Once you have firmed the soil back around the plant, make sure that you water it well, to settle the soil back around the roots.

Then remember that you should continue to water the plant well until it becomes established, especially during dry periods during its first summer.

“Make sure you mark where your peony is as it will die back in the winter and won’t appear until the spring,” Kate recommends.

“Marking your perennials when they’ve died back is essential when you are planting or re-planting,” says Horticultural Consultant Colin Skelly.

“Without this, you may well walk on and damage plants where there is no visible sign at the surfacethat they are there. There are times when I have planted too close because I have forgotten where I planted.”

5) Mulch Around Your Peony

Finally, you should mulch around the base of the newly planted peony with well-rotted organic matter such as garden compost, well-rotted manure or leaf mould.

This mulch will be important in adding fertility, improving the soil, conserving moisture and suppressing weeds.

The mulch should be refreshed in spring each year.

“The first three years are the most important,” says Kate.

“We don’t allow any plants to flower during those early years which means that the crown will increase in size and be able to support flowering for the next 100 years!”