Peonies are a clump forming herbaceous perennial. Once established Peonies look fantastic, the flowers are very showy and eye catching. Peonies need attention and can be quite fussy, and so have attracted the amber wheelbarrowindicating medium effort and maintenance. They are not fool proof, usually they do come up reliably every year but they can be tricky.
Peonies require a sunny site, good humus rich well draining soil on the Alkaline side. That said my soil is acidic and I can grow Peonies but I maybe just luck as they can be temperamental.
When planting Peony do not plant too deep the crown should be around 5cms (2") below soil level so quite shallow. If you mulch in the spring take care not to mulch over the crown. If your Peony is struggling you can try a balanced feed in the spring. The pattern of our weather the last few years has often produced a dry spring, in which case water the Peony to encourage the flowering.
The main maintenance requirement is to stake the plant every year when the new growth starts in the spring. Also at the end of the season, the foliage can look unsightly and so its best to cut it down. As a herbaceous perennial Peonies die right back to bare earth in the winter; the emerging spring growth is attractive, see image below right.
Peonies are spectacular; they have saucer like large showy flowers commonly reds, pinks, whites with a few yellow varieties. Peonies need staking/support before they get too tall and well before any signs of flower. This is a task I often leave until a bit too late, as a result it is then a nerve racking job of trying to thread leaves and flower stalks into the plant support without breaking anything. Peonies only flower the once so if a flower head is snapped, it will not flower. When growing Peonies it's much better to stake early and let the plant grow into the support. In the image left the support had been put in place a little late as usual, and so had to be eased over the foliage. Ideally it should be supported as the new growth emerges and before too many leaves are formed, image right.