One fundamental rule for successful tree peony cultivation is correct planting. This can be carried out from November to February, preferably by December-January if the season allows, when the plants are dormant. Though small, the plants should be put in reasonably large pots or in the ground, at a distance of at least 1 metre from one another: in this way they can grow into a thick bush.
The peony grows well both in the ground as well as in large pots, vats or boxes and in any kind of soil, though neutral or alkaline is preferable. In the case of very acidic soil, it is better to mix the soil with lime to increase its pH. The ideal soil is chalky and sand-rich; however clayey soils are good too as long as they are well drained.
It is better not to plant tree peonies too close to plants whose roots might compete with them for food and water. It is also essential that the soil can adhere well to all the roots without creating pockets where water can stagnate, causing the roots to rot and the plant to die. Therefore, once the hole has been made for planting, it should be covered with some loose soil capable of penetrating between all of the roots. The hole should be about 60 cm wide and deep.
When temperatures fall to below 0° C, planting is not possible: frozen soil is not loose, and will not adhere to the roots, which will inevitably rot. In such periods, even with a bare root peonies, it is better to wait for the soil to thaw before planting.
The bare root peony can survive for as long as one month if kept in cool areas in temperatures of no lower than 4° C and no higher than 10° C. In such cases, the plant must not be wrapped in plastic and with a little damp moss on its roots. If the peony should sprout during its time out of the soil, don’t worry, but it is best to proceed with planting as soon as possible, without cutting the shoots.
Once planted, the first fertilisation can be manure or sintered manure, taking care not to allow direct contact with the roots. To achieve this, hoe the area in question by mixing the well broken down fertiliser with the soil, two or three times in a row.