Chimonanthe, <em>Chimonanthus praecox</em>: planting, cultivation, pruning

Description and botany

Chimonanthe, or wintersweet (Chimonanthus praecox) is a bush of the family Calycanthaceae, native to China, where it grows in montane woods between 500 and 1,100 m.

The genus Chimonanthus includes six species of bush, most often evergreen (Chimonanthus campanulatus, Chimonanthus grammatus, Chimonanthus nitens), but also Chimonanthus praecox (syn. Chimonanthus fragrans), which is deciduous and is the only species commonly grown in our climate.

Of fairly slow growth, Chimonanthe forms a rounded bush made up of erect, ramified stems, arched at the tips. As tall as wide, it reaches on average 2 to 4 m in every direction at maturity in our gardens.

Chimonanthus praecox is a bush prized for its winter flowering and extremely fragrant flowers appearing on the still bare branches.

Beyond the Channel, it is nicknamed “wintersweet” — literally “winter sweetness” — so warming is its bloom to the garden still asleep in the cold; indeed in Greek its name means “flower of winter”. Its intoxicatingly scented flowers are remarkable because they appear in the middle of winter, from November in southern France and up to March depending on region and climate mildness. A scented flowering that will reward patient gardeners since wintersweet takes several years to flower, between five and ten years of cultivation before producing its first blooms.

The flowers, shaped like small pendulous bells 2.5 to 3 cm long and made up of 15 to 27 tepals, stud the bare wood. Waxy and translucent, they are and some varieties reveal a purple heart or a corolla and calyx washed with purple on the reverse, highlighted by a cluster of stamens. The Chimonanthus praecox ‘Grandiflorus’ bears larger flowers and is also distinguished by elongated, pendulous outer tepals and a mahogany-coloured centre.

With Hamamelis, Daphne and Sarcococca, it is one of the few scented shrubs in winter.

A & B flowers; C leaf; D fruit containing seeds; E longitudinal section of the fruit; F seed; G buds; H young shoot (Mihailo Grbić – Arboretum Beograd)

Its flowers literally scent the air, giving off a floral, spicy fragrance reminiscent of hyacinth, narcissus, orange zest and honey. Although fairly small, their profusion, warm tones and intense aromas warm the winter.

You can even make graphic winter bouquets with its branches still in bud, which will open earlier to scent your home.

The flowers turn into pubescent fruits shaped like small elongated pears about 4 cm long containing seeds that can be toxic.

On stiff, angular branches, a generous deciduous foliage unfolds at the shoot tips just after the flowers and is of interest. Long leaves 7 to 15 cm, single, opposite, oblong to elliptical with pointed lamina have a rough texture and paler veins. This usually mid-green, mostly leathery foliage, very rarely golden in some cultivars, takes sumptuous golden-yellow tones in autumn before falling.

Magnificent display of Chimonanthus praecox, all the more striking because it blooms in winter

Chimonanthe praecox is hardy and withstands winters down to -15°C. While it can be grown throughout France, it is easier to cultivate in oceanic regions where summers are warm and humid. Less demanding than Hamamelis, it accepts any fertile, moist, well-drained soil, even slightly calcareous. It is planted in sun or light shade and should be sheltered from cold winds and late frosts that can damage its very early flowering.

It can be installed in the ground as a solitary specimen or in a mixed border. Its slow growth allows container culture, so you can enjoy its scent on a terrace or near entrances.

Roots and bark of Chimonanthus praecox are used in Chinese medicine to treat rheumatism.

Main species and varieties

In France, only Chimonanthus praecox and its few interesting varieties are available commercially for their larger, more colourful flowers or their later flowering.

Most popular

Chimonanthus praecox

This is the type species. It is appreciated for its sulphur-yellow winter flowering, punctate with purple, and highly fragrant. Plant it as a specimen, at the back of a border or in a large pot.

• Hauteur à maturité 2,50 m

See the product sheet

Our favourite

Chimonanthus praecox Grandiflorus

This cultivar differs from the type by its larger bright-yellow trailing leaves and flowers with a dark red underside. Position it against a south-facing wall, in a flowering hedge, or in a large pot on the terrace.

• Hauteur à maturité 2,50 m

See the product sheet

Planting

Where to plant chimonanthe?

With fine hardiness, Chimonanthus praecox can withstand temperatures down to -15 °C, so it can be grown in all regions. However, it needs long warm but humid summers to flower well and will perform better in oceanic areas or south of the Loire. A situation sheltered from strong winds and late frosts that can damage its flower buds is recommended, as this bush needs as much summer warmth as possible to flower abundantly.

Regarding soil, it is a tolerant bush that copes with any good garden soil: rich, fresh, well drained, even slightly calcareous soil. However, although it adapts easily to all soil types, it prefers fresh soils that are not too dry.

It can be planted in sun but not scorching, or even in partial shade.

It fits well into all gardens, large or small, as a specimen to create an interesting focal point, in an informal flowering hedge with other spring-flowering bushes, or in a grouped border planted in threes or fives. In very harsh climates, it can also be trained against a warm wall of the house (south- or west-facing) to shelter it from frosts, which will ensure a good flowering display.

Its slow growth allows it to be grown in a pot provided it is pruned to maintain an attractive silhouette. You can thus enjoy its scent on the terrace or near the house and its magnificent autumn colours.

When to plant chimonanthe?

Planting of early chimonanthe is preferably done in spring, from February to March, avoiding frosty periods.

How to plant chimonanthe?

In the ground

The chimonanthe prefers neutral or slightly calcareous, well-drained soil. Space them at least 1.5–2 m from other bushes.

• Dig a wide hole, wider than deep, 80 cm x 60 cm
• Loosen soil thoroughly
• Lay a layer of clay pebbles or gravel at bottom of planting hole
• Plant at collar level without burying rootball too deeply in a mix of garden soil, well-rotted compost and a handful of horn meal
• Water
• Mulch around base to keep soil cool during summer

Follow our shrub planting tips.

In a pot

• In bottom of a container at least 50 cm diameter, lay a good draining layer of gravel or clay pebbles
• Plant in a good shrub potting mix blended with compost
• Mulch around the base
• Water thoroughly
• In summer, water as soon as soil is dry

Maintenance, pruning and care

Chimonanthus requires very little maintenance. In summer, monitor water needs, and water well during hot spells; soil must never be dry. Provide mulch at base of bush before winter to protect from severe frosts and in March to keep soil cool.

Once a year in spring, if necessary, amend soil with horn meal.

You can keep a chimonanthe in a container provided you prune it each year. Remember to apply fertiliser once a year and to water well during heatwaves or prolonged drought.

When grown in suitable conditions, Chimonanthus praecox is a bush largely resistant to most diseases and parasitic pests.

Pruning chimonanthe

When and how to prune?

Pruning is not necessary. However, if you want to preserve an attractive silhouette, carry out maintenance pruning. Only intervene after flowering. This pruning is not essential every year :

1. Rebalance or reduce its branches by removing crossing or thin branches
2. Remove dead wood

Follow our advice on how to prune early-flowering bushes!

Propagation

Chimonanthus se multiplie facilement by layering in spring. As this bush produces fruit, sowing is possible in autumn in a cold frame, but more delicate and demanding.

Layering

Root development of Chimonanthus praecox layers is fairly slow, so be patient!

• After flowering, bend one shoot down to base of bush where it naturally touches the soil
• Remove leaves from this section of stem
• Score bark over 5–10 cm with a small knife
• Dig a furrow in the soil close to base of bush
• Lay the shoot into it and partly bury it under a mound of soil so it can take root
• Backfill the furrow and secure the layer with metal hooks (tent-peg type)
• Raise the tip and stake the aerial part
• In following spring or autumn, separate the layer from mother plant if it has sufficient roots
• Replant in chosen location

Associate

Still too little-known, the Chimonanthus odorant or Chimonanthus praecox deserves a place in winter scenes, on a par with Hamamelis. It thrives in all natural and naturalistic gardens, where its scented, colourful flowering brings a cheerful touch to garden still numbed by cold.

In a mass planting, you will make the bright colour of its flowers stand out against a permanent green backdrop made up of conifers and bushes with evergreen foliage such as Pieris, Choisya, Euonymus.

A planting idea: Chinomanthus praecox (photo TANAKA Juuyoh), Heuchera ‘Obsidian’, Jasminum nudiflorum, snowdrops and hellebores, crocus

In a scented composition at heart of winter, surround it with Daphnes, Sarcococcas or Camellias.

In a loose, flowering hedge it can be paired with bushes with winter flowering such as Hamamelis or spring-flowering ones such as Forsythia, Magnolia, Japanese quince, Kerria japonica or Edgeworthia or paperbush.

Its golden flowers will offer a striking contrast with blue of early small spring bulbs such as Muscari azureum, crocus, hyacinths, ipheions or scillas, erythroniums.

Magnificent at heart of winter, after flowering, chimonanthe will take on a rather unassuming appearance before bursting into colour again in autumn, so do make sure to surround it well! Perennials with winter flowering, winter heathers, Hellebores then Vinca minor will dress its base, while Heucheras and heucherellas will accompany its golden foliage in autumn.

In a Japanese-style zen garden, its bare twigs studded with small flowers will work wonders alongside sacred bamboos, deciduous azaleas or Japanese maples.

If you train your chimonanthe against a sunny wall, pair it with a climbing plant such as a clematis or colourful or scented annuals such as sweet pea, climbing nasturtium, Cobaea around which they will twine.

→ Discover other pairing ideas with Chimonathus in our advice sheet!