- Botanical Name
- Paeonia lactiflora. Itoh: P. hybrid. Tree: P. suffruticosa.
- Family
- Paeoniaceae
- Plant Type
- Herbaceous perennial.
- Size (HxW)
- 60-120cm x 45-90cm. Tree: 30-150cm x 30-150cm
- Depth & Spacing
- Plant with the rhizome lying across with the eyes approximately 2-3cm under the soil surface in a pre prepared position (see ‘Soil’). Plant at least 60cm apart. If you plant too deeply you will get plenty of leaves, but no flowers. If you have one in the garden, and it is lack lustre, this can sometimes be the reason – you can raise it during dormancy, taking care with the delicate root system.
- Soil
- Prepare the soil with loads of well rotted organic matter to at least 40cm in depth. Ideally the organic matter would be a couple of handfuls of chicken manure combined with a handful Potash.
You should also add plenty of Dolomite lime when planting. They are endemic to limestone soils, so it is impossible to give them too much. Also lime doesn’t dissolve easily, so the more the merrier. Lime is non toxic so won’t damage your soil and won’t spread laterally to bother neighbouring plants. Dig over well and leave for one week prior to planting. This will ensure plenty of food as well as good drainage. Peonies require loads of feeding to flower at their best.
- Aspect
- Full sun to afternoon shade is ideal, in too much shade they won’t flower well. Be careful with the roots when planting they are easily damaged. Too much shade and they will be slow to grow and become leggy. Ideally they should be in an open sunny spot, away from the competition of roots from large trees (they are hungry and don’t like to fight for their nutrients) and with protection from strong winds.
- Climate
- Cool to Temperate – they need cold winters to flower well (3-5C).
- Frost
- Hardy although new growth may be marked by late, heavy frosts, they are easily pruned off when the weather warms.
- Water
- Keep well watered during the growing season. It is a good idea to mulch around the plant to help with water retention. They don’t like to sit in water over winter – who does – so the soil should drain well. They will become dry tolerant once they established.
- Fertiliser
- Fertilise twice a year, autumn and spring – an easy way to remember is Anzac Day and Melbourne Cup Day. Apply Blood and Bone/Dynamic Lifter and Potash each year. You should add at least a few handfuls of lime every year too to keep them happy and healthy. They are doing much of their feeding when there is no growth above ground.
- Flowering Time
- Spring to summer. Peony flowers are big, so they may need a bit of support (rings/stakes), especially the double varieties. It will also help to best show off the blooms.
- After Flower Care
- Cut off any spent flowers and foliage to tidy. Prune hard in autumn, after the flowers have finished and the foliage has yellowed, they will reshoot in spring. Remove fallen leaves to avoid disease issues. Tree Peonies: Once the plant is established, after a few years, prune out the soft growth and leave around 6-10 of the best branches to create an open structure, allowing sunlight to penetrate and good air flow.
- Notes
- Mulching in spring will help protect the root system from heat stress, especially in dry summers. They require a cool root system. They may not flower in the first few years as they are busy growing their extensive root system (they have a lot of flowers to provide for in the future) this is completely normal, enjoy the foliage in the meantime and don’t forget to feed them.
Once your Peonies are mature enough to flower you might have the scissors ready and raring to go. But you should take it easy for the first year or two to give them plants as much leaves as possible to invigorate and establish the root system (which can grow up to 90cm and weight 30kg or more).
It is a good idea to protect new shoots from slugs and snails. When required, dig and divide early autumn. If you are computer savvy, there are lots of Youtube videos on this if you want a practical demonstration, basically use a knife to cut the roots into pieces – each piece should have three growing shoots or eyes.
They need good air circulation is important as it prevents disease, black spots or grey mould are signs of Botrytis which thrives in cool, damp conditions without good air flow. Remove any affected parts of the plants and dispose of them. Tree Peonies: First flowers may not be true to size and colour, do not be disappointed, allow one or two seasons for them to develop. In autumn it is good practice to remove the fallen leaves from underneath the plant to avoid disease – they may contain mildew spores which will endure and cause damage in spring. Remove old or broken branches as required.
