Peonies are perfect for busy people. Once planted they require almost no attention. Long-lived and extremely beautiful when in flower even the foliage is handsome. However there might be a time when they might need moving or dividing.
Despite the gardening myth that peonies cannot be moved, we replant our crop of peonies every few years to prevent the plants becoming too large as this makes them difficult to lift. This is not something the gardener need worry about, but if your peony is too big for the spot it is growing in, or you want to give someone a piece of it, or perhaps you are moving home and you don’t want to leave your precious plant behind - don’t worry it can be lifted and divided. Granted it might take three years or so to settle down properly, but depending on the size of the division it is possible to have flowers the following season.
When to move and divide a peony
Moving and dividing peonies should be done in autumn once the leaves have died back. This can be any time from October to February.
How to divide a peony
Firstly dig the plant out of the ground. Depending on its age, you might need a fork or a spade. We often use a mini-digger! It is likely that you will not get all the plant out of the ground. It does not matter if the thick roots snap in half as it won’t hurt the plant, but try to lift as much of it out of the ground as possible. You will find that peonies with bulbous roots such as Paeonia officinalis types will regrow if some root is left in the ground. This can be a blessing or a curse!
Cutting the plant up
Once it is out of the ground, blast it with water from a hose pipe to clear away the soil. This will help you to find the pink ‘eyes’, or leaf buds. The eyes are next years leaf shoots and this is where you need to aim for when splitting the plant apart. Each division should have at least 3 eyes for it to stand a chance of flowering next year. The bigger the plant the better so try for 5 to 8 eyes.
Firstly take a good look at your lifted plant. Starting from the eyes and seek out the ones with most root attached. It is easy to slice away and end up with eyes and no roots. Using a large, sturdy knife or pair of secateurs insert the tip of the blade around the top of the plant and carefully slice downwards. With luck and a bit of practice you will be able to divide the plant into some nice pieces ready for planting.
Peonies are tolerant plants. As long as a few rules are followed they are easy to grow and once established will live for many years with little attention.
What peonies like
Peonies should be grown in a reasonably rich, well-drained soil. If your soil is poor it helps to dig in some VERY well rotted compost. Garden compost that is not fully broken down can cause a peony to rot. They also prefer a position in full sun, but I have a peony ‘Shirley Temple’ that thrives in part shade, so this rule can be broken.
How to plant your peony
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.
The important rule
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.