Plant peonies in a rich but well-drained soil in a position of full sun. Avoid planting these often expensive plants in a waterlogged soil. The majority of herbaceous peonies prefer a neutral or slightly alkaline soil.
Tree peonies need a sheltered position and are more tolerant of acid soils.
Bare-root plants should be planted as soon as they arrive. Peonies prefer being planted in autumn or spring. Ensure that plants are not planted too deeply. Those planted too deeply will result in poor plants. Mix in plenty of well-rotted organic matter before planting. Apply a balanced fertiliser in spring.
Avoid overwatering newly planted peonies as this is a common cause of plant failure.
As the flowers are so weighty, peonies, especially the herbaceous types, will require a plant support.
Herbaceous types can be propagated by division in autumn. Cut the faded foliage back and lift the plant with a garden fork. Remove as much of the garden soil as possible and with a knife cut off sections of the crown. Each section should have at least three buds and plenty of root. Replant straight away in the garden.
Don’t try to divide tree peonies. Instead, you may be able to try layering a pliable stem, or sowing seed.
The most common problem is peony wilt. This is a botrytis that causes the stems to rot. To avoid this fungal attack avoid planting plants too close together. If you see leaves with dark spots on them remove them as this will help to reduce the spread. When cutting back herbaceous types in autumn clear up all the foliage to avoid reinfection in spring.
Peony buds are very appealing to ants. It’s not unusual to see the buds crawling with ants. Don’t worry, they will not damage the plant.
Herbaceous peonies should be cut back hard in autumn to ground level. Tree peonies do not need pruning. All you need to do is remove the faded seed heads in autumn. Don’t be tempted to pick off the faded foliage in autumn – let it fall off naturally. Avoid pruning tree peonies hard back as they are often grafted onto herbaceous peonies.
When weeding borders try to avoid stepping on the newly forming buds of the herbaceous types.