Forget the myths, peonies are easy to grow. In fact, once established they will live for more years than most people are likely to inhabit their houses. When you move house they can come too.
Peonies need a soil that does not become water-logged at any time during the year. A good well-drained loam is ideal, but they are just as happy in a clay soil provided it does not stay wet. Being plants of the open ground they prefer full sun, but they are able to tolerate a light shady site. They can take up to three years to flower, but once established can live for more than 50 years.
This is simple. Dig a hole wide enough and deep enough to accommodate the roots of the peony. Place the plant in the hole - following the rule below - and cover with soil.
Herbaceous peonies - the ones that die right back in autumn - should be planted with the eyes no more than 3cm (1 inch) below the soil surface. Despite also producing short woody stems this rule also applies to Intersectional peonies. If you are planting tree or woody peonies (such as P. delavayii) the eyes should be at least 7cm (3 inches) below the soil surface. If they are planted at the wrong depth they may fail to bloom or at the very least take years to flower.
I only fertilise peonies every now and again, perhaps every third year. Being deep rooted plants and slow to multiply they have the ability to search out the best bits of soil. A mulch of good, well-rotted manure or garden compost can be applied in late autumn or spring if you so desire. But make sure this is not placed over the plant as it can cause the eyes to burn and therefore rot off as they start to grow. One of the best fertilisers to use is Bone Meal, but any good general fertiliser is fine.
Contrary to what has been written in the past, peonies do not mind being moved - especially if they are not divided. If a plant has become too large, and needs to be divided, make sure the transplanted clumps have at least 3 eyes (leaf buds).
The only ailment peonies may suffer from is botritys, a fungus that tends to increase when the weather is damp. Evidence of it can be found at the base of the stem or on the bud, which become brown and mouldy. If this happens remove the infected foliage and spray the plant with a fungicide.
There are three reasons why peonies fail to flower.
1. They have been planted too deeply. Lift the plant in autumn and replant with the buds no more than an inch below the surface of the soil.
2. The plant is too dry during the spring growing season. This can be recognised when the buds fail to swell and stay small and look dried up.
3. The plant is growing in a very shady spot, which can lead to dry roots.
Sometimes we asked why spots appear on the leaves of peonies. This tends to occur later in the summer just before the plant starts to enter it’s dormant state. The foliage of some varieties of herbaceous peonies start to change colour in late August. There is no need to worry about this.
Another question often posed is how to get rid of ants that appear on the buds. The answer is don’t. In my experience ants do no harm. They appear as the flower bud swells, feeding on the sugary substance that exudes from the bud. The ants may even help the bud to open properly. As soon as the buds open the ants disappear.