The most difficult question for a plantsman to answer is “what is your favourite flower?” My usual response is “well, it depends on the time of year.” But if I had to choose just one family it would have to be paeonies, and if I was forced to choose one of those, then Paeonia rockii would come top of the list.
Paeonies generally fall into two categories, herbaceous and tree (although there are now intermediate or Itoh paeonies, the result of crossing the two categories). Herbaceous paeonies grow from ground level every year, while tree paeonies (actually shrubs rather than trees) produce a woody superstructure on which to carry their blooms. These originate in China where they have been bred and cultivated for centuries. Early plant explorers were only able permitted by the Chinese to bring home seeds of cultivated varieties rather than the species. One of the most spectacular was named “Joseph Rock” after an Austro-American plant explorer, but is now known as Paeonia rockii.
P. rockii is very hardy (it can take temperatures below -40C), although young growth and flowers can be damaged by late frosts. It grows into a lax shrub some six to seven feet tall and wide, and prefers an open sunny position in a fairly neutral soil that does not become waterlogged. The scented flowers are semi-double and up to eight inches across. Seed raised plants are variable in flower colour, but the most desirable form has blooms that are white with a stain in the centre the colour of blackcurrant juice, while the foliage is dark green and divided.
The plant in my garden arrived as no more than a few twigs nearly ten years ago. Since then it has matured into a bush carrying more than fifty flowers. In a cool cloudy spring these last up to three weeks, but in bright sunshine they finish in a week or so. Maybe this fleeting appearance makes them my favourite, but who could resist a bush of Paeonia rockii in full flower?