Not actually trees, nor the more familiar herbaceous perennials, to which they are related. Tree peonies are hardy, long-lived shrubs, esteemed by ancient Chinese emperors and Victorian plant-lovers alike for their handsome foliage and spectacular display of stunning flowers in May/June. Although their leaves drop in winter, they keep a woody framework of stems which burst into new growth in early spring. A mature tree peony may reach a height of 1.5m – 2m (5′ – 6′) with a similar spread. With leaves and flowers much bigger than ordinary peonies, they make an excellent addition to garden borders in a well-drained, sunny or lightly shaded site, sheltered from cold winds. Avoid planting in frost pockets as extreme cold may damage new growth and flower buds. Tree peonies may also be planted in large pots in a soil-based compost such as John Innes No. 2 or 3, but be sure to refresh the soil every few years and pay extra attention to feeding and watering – do not over-water. To get the best out of your tree peonies, in spring when the soil is moist, apply a top dressing of a general fertiliser such as fish, blood and bone and then mulch with garden compost, composted bark or well-rotted manure (being careful that the mulch doesn’t touch the stems). As well as enriching the soil, the mulch will help retain moisture, discourage weeds, and help protect the roots from temperature extremes.
Taking extra care when planting tree peonies will help avoid disappointment in later years. As they are usually grafted onto herbaceous peony rootstocks, you should plant pot-grown tree peonies slightly deeper than the soil level of the pot. The grafting union (the point where the rootstock and the tree peony join near the base of the stem) should be covered by 8-10cm (3″-4″) of soil to encourage the tree peony to develop its own roots (and avoid the rootstock from sending out suckers.) Should suckers appear growing from the base (the leaves will be different to the rest of the plant) then cut them off to avoid the rootstock taking over.
Common causes of non-flowering are dry soil in spring and lack of adequate sunlight, so think carefully about the site you choose for planting. Also beware of over-feeding, which may produce lots of foliage to the detriment of flower production. Don’t worry if your newly-planted tree peony doesn’t produce flowers or appear to grow much in its first season or even its first few seasons – it can take up to 4 years for them to ‘settle in’ and healthy root development is more important at this stage. Planting with bonemeal or mycorrhizal fungi should encourage a strong root system to help get your plant established quickly.
Even if you don’t have room in the garden for a tree peony yourself, then consider buying one for someone else. As the national flower of China, popular for their medicinal as well as aesthetic qualities, they are considered symbols of love, wealth and good luck – they make perfect presents!
March 2021 – We currently have 3 different sizes of Paeonia suffruticosa in stock, with prices ranging from £11.99 to £23.99.