Paeonia x suffruticosa Tong Yun - Tree peony

Preferably plant tree peony Tong Yun (Valentine) in partial shade, or in full sun in northern regions. Six hours of sunlight per day are necessary to achieve beautiful flowering. Contrasting climates (continental), with marked winters and springs and hot summers, favour particularly abundant flowering. Morning sun is especially appreciated in Mediterranean areas, as scorching situations should be avoided. Plant it in fertile, deep soil, slightly acidic, neutral or even slightly chalky, moist but well-drained. Once well established in deep soil, tree peonies require no watering in summer, particularly the varieties that flower early in spring. Its cold resistance is excellent, but the flower buds can be damaged by strong, dry or cold winds.

Easy-going tree peonies require little care but deserve careful planting. When planting, dig a large hole 40 to 50cm deep and at least as wide. Fill it with a mixture of garden soil, leaf mould, and river sand or gravel if your soil is very heavy and compact. Add crushed horn, bone meal and dried blood to the bottom of the planting hole. Tree peonies dislike competition from the roots of other plants; allow a spacing of 1m from neighbours. The graft must be buried about twenty centimetres deep so that the plant gradually becomes independent from its rootstock. Water abundantly but spaced 8 to 15 days apart for the first two years, from March to September. Peonies have a reputation for not liking disturbance. That is why they should not be moved after planting. Avoid pruning unless the plant becomes bare at the base. If this is the case, prune at the level of the basal shoots. Provide a stake to support the flower stems and cut off faded flowers.

It can be grown for several years in a very large pot, provided it is given a deep container with several drainage holes. Choose a tub at least 50cm in diameter, with 40 to 45cm of actual depth; a volume of 60 to 80 litres is suitable. Prepare a consistent mixture, composed of about 40% slightly clayey topsoil, 40% rich potting compost and 20% fine lava rock, pumice or fine gravel. Place 3 to 5cm of coarse lava rock at the bottom of the pot. Position the peony in morning sun or soft light, as dark pots quickly heat the roots. Water regularly during the growing season, without allowing water to stagnate in a saucer. In winter, leave the pot outdoors as the plant needs the cold to flower well again.