Paeonia suffruticosa Seeds | Peony Tree Pink
LATIN NAME: Paeonia suffruticosa
COMMON NAME: Tree Peony, Moutan Peony
Plant Profile
Paeonia suffruticosa is the only peony that makes wood and stands as a shrub, so it opens its great pink bowls on last year’s branches instead of from a soft crown like the garden peony. For a thousand years Chinese growers bred it as the king of flowers, and a single old plant still outlives the gardener who set it, which is why a courtyard tree peony is treated as heirloom.
Unlike the herbaceous peony that dies to the ground, the tree peony keeps a woody stem two metres tall, with deeply divided leaves and, in late spring, very large single or double flowers in pink, rose, white, crimson and purple. The woody frame is what lets the bloom sit above the leaf, and the bark is grey and shredding on old wood.
The herbaceous Paeonia lactiflora shares the flower but dies back each winter, while the tree peony holds its wood and flowers a touch earlier. Seed pods split to show a few large, glossy black seeds, which is the sign you can grow your own rather than buy a graft, and a seedling tree peony is the start of a new line rather than a clone of an old one.
Wild parents came from the dry hills of Gansu and Shaanxi; cultivation spread east to Luoyang and Heze, now the great peony cities. The plant likes a cold winter and a dry, airy summer, the opposite of wet tropics, which is why it sulks in humid lowlands and thrives where the air is bright and the drainage sharp.
Choice tree peonies are grafted or divided to hold a colour; seedlings give the mixed pinks of the species and are the route to new cultivars. Tissue culture is used for clean stock of rare forms, and a seedling bed is where the next named pink is most likely to appear after a wet, warm summer of open bloom.
Science & Biotechnology
The root bark, sold as moutan bark, carries paeonol and the paeoniflorin and galloyl glucosides also found in the herbaceous root. These are the markers used in the drug, and they are what researchers track when comparing wild and cultivated lines, since the bark’s value rides on the paeonol level more than on the flower colour.
The pink and purple hues come from anthocyanins layered over a yellow ground, and breeders select for clean colour and strong substance. Micropropagation and grafting onto herbaceous rootstocks fix a prized form faster than seed, so the show cultivars at a festival are nearly all clones rather than seedlings.
Uses & Benefits
Planted as a lawn specimen or against a wall, the tree peony is the centrepiece of a spring garden and the subject of flower festivals in Luoyang and Heze. A mature plant carries dozens of bowls at once, and a single well-placed shrub can carry the whole front of a border through late April and May.
The dried root bark is a standard herb, sliced and decocted, distinct from the root of the herbaceous peony. The flower is also candied and used to flavour tea in parts of China, so the same plant serves the vase, the shelf and the sweet jar across the year.
Cut tree-peony flowers ship for the holiday trade and last well in water; the woody stem carries the heavy bloom without flagging, which the soft peony cannot match. A bud picked at the right stage opens indoors over several days, which is why the cut flower is worth more than its garden beauty suggests.
Growing from Seed
Tree-peony seed has a double dormancy: sow fresh, cleaned seed in a warm moist spell, then a cold one, and the root and shoot follow in turn. Cover at about twice the seed depth in a gritty loam and keep it from drying, because a dry seed coat resets the clock and the seedling may skip a year.
Move seedlings to tubes at eight centimetres and plant out when the stem reaches twenty-five centimetres, setting the graft union or crown just at soil level. Space specimens one and a half metres for a mature shrub, and keep the young plant staked only lightly so the wood hardens straight in the wind.
Give full sun but dappled shade at the hottest hour, and sharp drainage. Prune only to open the centre and take old wood after bloom; the plant is hardy and needs little feed, asking mainly for dry air in summer and a mulch of grit rather than wet compost against the crown.
Our Take
The tree peony rewards a patient hand more than a busy one. For the soft sister, see Paeonia lactiflora, the wild Paeonia veitchii, and the sliced moutan bark slices. The white peony root is the herbaceous side of the same shelf.
Related Reading
Gardeners who grow Tree Peony often pair it with these related subjects: