Kelways Guide to Herbaceous Peonies
Receiving Your Peony
Traditionally we send out field grown plants in the autumn and early winter. This is the best time to plant, but they can be also be planted in the spring. Peony “crowns” have pink buds at the top. Don’t worry if you see a white fungal bloom on parts of the roots. This is quite normal. If you can’t plant for a few days, keep them in a cool dark place and the plants will be fine.
Pot grown peonies are supplied all year and can be planted any time that the soil is workable.
Peonies are extremely hardy and adaptable. They grow best in full sun; you can expect fewer flowers in light shade but the blooms will last longer.
Single flowered cultivars seem to do better in shade than doubles. Peonies will grow in most soils provided they are not too wet in the winter. They well on chalk and in fact prefer slightly alkaline conditions. If your soil is acidic include a handful or two of lime at planting. A heavier soil is preferable to a light one, but it is always beneficial to add some organic matter, which will also improve moisture retention if your soil is dry. In exposed and windy areas, taller varieties may need staking.
Planting Your Peony
Good soil preparation before planting will reap rewards in future years.Dig a hole at least 30cm(12in) deep and wide. Mix in some garden compost and a handful of bone meal or general fertiliser. The most important rule is avoid planting too deeply. The top of the crown (the buds) should be no more than 5cm(2in) below the soil surface. Planting too deeply is the most common reason for a peony failing to flower.
DO NOT OVERWATER NEWLY PLANTED PEONIES, THIS IS THE BIGGEST CAUSE OF FAILURE, PARTICULARLY WHERE THEY ARE PUT INTO DECORATIVE CONTAINERS. IF IN DOUBT....DO NOT WATER
Container grown plants are already potted at the correct level, so plant to the same depth. Don’t worry if the compost falls away while you are planting. If you are planting a group of peonies allow about 75cm(30in) between the plants. Flowering normally starts from the 2nd year after planting.
Peonies will live for 50 years or more; although they can survive considerable neglect, they will reward extra care. In the autumn cut down the dead foliage at ground level and clear it away. Top-dress with a handful of bone meal or general fertiliser. If mulching, avoid smothering the top of the crown or the plants may become too deeply buried and stop flowering. With acidic soils, an occasional top dressing with lime will prove beneficial.
Watch our video below on how to plant herbaceous peonies:
Growing Peonies in Pots
You can successfully grow and flower peonies in pots. Choose a pot at least 30cms (12 ins) in diameter with adequate drainage holes at the base. Use a soil based compost such as John Innes No3. Peonies do not thrive in peat-based composts. Do not overwater, and preferably keep on the dry side. After a few years, plant them in the garden where they will ultimately thrive better.
Move peonies in the autumn. As long as they are replanted at the same depth as before, then flowering should resume without interruption. Although peonies seem to go on forever, they begin to lose vigour after about 20 years and benefit from being dug up and split. This is best done in the early autumn as the foliage dies down. The crown should be carefully lifted and the soil washed away to expose the eyes. Using a heavy knife or a pruning saw, remove any dead, woody root, and then cut the crown into pieces each containing about 3-5 eyes. These can be replanted.
Peonies are remarkably pest and disease tolerant. Rabbits and deer do not touch them. Vigorous, well-grown plants rarely have problems. The most common problems are fungal diseases. Peony Wilt (Botrytis) can cause stems to rot and collapse, usually just before or after flowering. Cladosporium can cause dark blotches, on the leaves from July onwards. Generally neither of these conditions will kill a peony.
Good hygiene and cultural practices is the key to preventing and dealing with any fungal attack. Maintain a good airflow around plants by not overcrowding them, particularly at ground level. If any stems collapse with Botrytis, or if any leaves become spotty, remove them immediately which will help prevent the spread of infection. In the autumn cut off all the foliage and dispose of to prevent reinfection the following spring.
Peonies and Ants
As the flower buds develop they exude a sweet sugary substance. This is a magnet to ants, which often can be seen crawling all over the plants. Don’t worry. They will not damage your peony, unless they nest within the roots.
- Plant in a sunny or lightly shaded position
- Most soil types, but preferably not too wet in the winter
- Add plenty of organic matter when planting.
- Plant with the top of the crown no more than 5cm below the soil surface
- Feed with a general fertilizer in the spring, and again in the autumn
- Move or divide in the autumn