If you want a reliable display of colour every year but do not want to put in hours of hard work, then herbaceous peonies are the plants for you. Their flowers are every bit as beautiful as roses, most are strongly scented and make excellent cut flowers. They are often called roses without thorns and are less troublesome. They suffer from few diseases, aphids and slugs.
Flowers vary in size from singles to doubles with most flowers having a red or pink colour. There are a few varieties with yellow and almost white flowers.
Peonies grow best on a fertile soil but will tolerate a sandy soil if given a regular mulch of compost. They do not like a water logged soil, especially in winter. They prefer neutral or alkaline soil and do not like acid soil with a pH of less than 6. They are very hardy, so they are ideal for gardens in colder areas. They flower best in full sun but will tolerate partial shade. Choose a position sheltered from winds.
Plant peonies in autumn to allow the roots time to get established. Since they grow for years if undisturbed, prepare the ground well with lots of compost added in. Plant with the buds about 2 inches below the surface, planting too deeply is one of the reasons peonies do not flower. Peonies take a while to settle down so do not be worried if they do not flower in the first or second year. They are quite drought tolerant, but a mulch of compost will conserve moisture around the roots.
Watering during dry spells in spring helps to produce more flowers. Did I say water, no need to water any plants so far this year, but next year could be very different.
Most peonies are self supporting but large flowering varieties can droop under the weight of the flowers. Place a plant support around the clump as the flowers emerge so the stems grow through it. Peonies are usually resistant to pests and diseases but can suffer from botrytis, brown areas develop and rot.
Remove infected material and spray with a fungicide. Paeonia tenuifolia has cup-shaped red flowers with yellow stamens.
Tree peonies have woody stems which produce large fragrant flowers similar to the herbaceous peonies. Tree peonies are super shrubs with a permanent woody framework for winter interest. From April to June they produce flowers, similar to herbaceous peonies, in a wide range of colours from snowy white to delicate pink to rich maroon.
All flowers have a fragrance, some are exceptionally perfumed. The size of the blooms is where these plants really show off. Mature plants can produce dozens of large blooms on woody stems that are 6-8 feet tall. They also produce very attractive foliage.
They are expensive plants to buy because it takes time and skill to successfully propagate them. They can take a few years before they produce flowers. They like a well-drained, fertile soil in partial or dapple shade.
Feed them once a year with well rotted manure or compost. It is best to plant them in the autumn so that the new feeder roots are established before new growth starts in spring. No pruning is necessary except to remove any dead wood in spring when the new foliage appears.
Paeonia delavayi produces dark red flowers, Paeonia lutea X delaveyi has pink flushed yellow flowers, Paeonia ‘Souvenir de Maxime Cornu’ has double yellow flowers with ruffled petals.
Jobs for the week
Prune the dead flower stems of hellebores, cutting them back to the base to make room for new shoots.
Tuberous begonias and dahlias can be planted out in the garden when the danger of frost is over.
In the greenhouse prune the vine to two leaves beyond a fruit truss.