Tree peonies are not trees at all, but, they are true peonies. They have woody perennial stems, and are relatively hardy multi-stemmed shrubs, that can grow from four to six feet high and just as wide. Their ultimate size depends on their growing conditions. There are a few that have a dwarf habit. Blooms look like crepe or tissue, in an array of colours including white, pink, red, purple, and yellow, blends of colour and flares or blotches.Tree Peonies do best in a sunny to partly shady site, holding their flower colour longer if planted when morning sun provides most of the light, in average, well-drained, evenly moist garden soil high in organic matter. Space plants 3-feet apart for a hedge. Tree Peonies rarely need pruning, except to maintain a desired shape and size or to remove damaged canes.
Tree Peonies are grafted plants. Plant the graft union 4 to 6 inches below the soil surface as shown in the photo. This helps the plant develop its own roots. The graft union looks like a bulge on the main stem just above the roots. After planting, only an inch or two of the woody stem may show above the ground.
Tree Peonies are slow-growing plants that reach mature size in 5 to 10 years. Try not to transplant them, as this will slow their growth as they re-establish their roots in the new location. Tree Peonies can live up to 100 years or more!
The need for fertilizer is dependent on local garden conditions and specific recommendations cannot be given. Avoid high nitrogen fertilizers. Balanced fertilizers or those designed for flower or vegetable garden use should work well. A healthy soil almost always grows healthy plants of any kind. Regular application of good compost creates a loose, friable, well-drained and well aerated soil for all your plants.