In short
- The clove-and-spice fragrance is the main reason to grow it - one of the strongest among spring-flowering shrubs.
- Blooms in April and May: carmine-pink buds, white open flowers, hemispherical clusters 5-8 cm across.
- Grows slowly: it reaches its ultimate 1.2-2.4 m in height and a similar spread only after 10-20 years, so it fits a small garden for a long time.
- Prune only immediately after flowering: the buds for next spring are set in summer.
- The fruit, ripening from red to nearly black, is sparse, inconspicuous and inedible - unlike the ornamental fruit of the guelder rose.
Botanical data
- Family
- Adoxaceae (Adoxaceae)
- Height
- 1.2–2.4 m
- Width
- 1.2–2.4 m
- Habit
- Rounded
- Growth rate
- Slow
- Position
- Full sun, Partial shade
- Soil
- Loamy, Humus-rich, Sandy, Chalky
- pH reaction
- pH 6–7.5
- Moisture
- Moderate, Moist
- Bloom
- April–May
- Hardiness
- USDA 4b–7b
- Propagation
- From cuttings, From seed
Characteristics
A shrub with a dense, rounded habit, usually growing to 1.2-2.4 m in height and a similar spread. It grows slowly and reaches its ultimate size only after 10-20 years, so it fits a small garden for a long time. Young shoots are densely downy. The leaves are broadly ovate, often slightly heart-shaped at the base, irregularly toothed, about 4-9 cm long, dull green and covered on both sides with star-shaped hairs, which makes them velvety to the touch. In autumn they turn wine-red and purple, though the intensity of the colour varies from year to year and can be moderate. The inflorescences are terminal, hemispherical corymbs 5-8 cm across, opening in April and May together with the leaves. The buds are carmine-pink and it is they that give the shrub its pink tone just before full bloom; the open flowers are white or pale pink. A single flower has a narrow corolla tube about 8 mm long. The nectar hidden deep within it is accessible mainly to insects with a long mouthpart, chiefly butterflies; bees use these flowers as a source of pollen rather than nectar. Full bloom lasts about two weeks. The fruits are flattened, egg-shaped drupes about 6 mm long, ripening in late summer from red to nearly black. They set irregularly, are few and usually hidden among the leaves, so they are not an ornamental feature; nor are they fit to eat. For care, the most important thing is the phenological sequence: the flower buds for next spring are set as early as the summer of the same season.
Popular cultivars
- ‘Aurora’
- Buds dark pink to red, opening into pastel-pink, strongly fragrant flowers. Young leaves with a coppery cast, red in autumn. Habit broad and spreading; the shrub reaches about 1.8 m in height and spread.
- ‘Compactum’
- A dwarf, slow-growing cultivar with a dense, rounded habit, growing to about 0.75-1.2 m. It flowers typically for the species: pink buds, white flowers in rounded clusters. The best choice for small borders and containers.
- ‘Diana’
- Buds red, flowers pink once open, darker than in the species. Young leaves with a purple-chocolate tone that fades over the course of the season.
- ‘Charis’
- A cultivar with stronger growth than the typical form of the species, flowering pure white. Chosen where the shrub is to reach its ultimate size more quickly.
- ‘Spice Baby’
- The trade name of the cultivar SMVCB, obtained from open pollination of the cultivar Compactum. Compact and rounded, it grows to about 1.5 m; flowers in pale-pink clusters, leaves red to burgundy in autumn.
- ‘Spice Girl’
- The trade name of a cultivar with strong, bushy growth, reaching about 1.8-2.1 m. The clusters are large; red buds open into pink flowers that fade to white.
Growing and care
Watering
Once established it tolerates short spells of drought, but reacts badly to constantly wet, compacted soil - on such sites it is prone to root rot. Water above all in the first two seasons after planting and during prolonged heat.
Fertilizing
On average, fertile soil a spring mulch of compost is enough. Excess nitrogen produces lush shoot growth at the expense of setting flower buds.
Planting
Average, well-drained, moderately moist garden soil; it tolerates substrates from sandy to loamy and calcareous, and reactions from slightly acidic to slightly alkaline. Avoid hollows where water stands after rain. A site sheltered from the strongest winds holds the fragrance around the shrub for longer.
Pruning
Prune minimally: remove spent flower clusters and shoots that are damaged, diseased or crossing. Rejuvenate crowded, old shrubs gradually, cutting out single oldest shoots at the base over successive seasons - the species grows slowly and rebuilds its shape over years after hard pruning.
Companion plants
Good companions
Narcyzy kwitną tuż przed kaliną i zachodzą na nią w kwietniu, u stóp krzewu jeszcze niezacienionego liśćmi, a latem zamierają — nie konkurują więc o wodę w okresie, gdy kalina zawiązuje pąki na przyszły rok.
Oba krzewy mają podobne wymagania (słońce, przepuszczalna gleba, tolerancja odczynu obojętnego), a kwitną po sobie — kalina w kwietniu i maju, lilak w maju — co wydłuża sezon zapachowy w ogrodzie.
Funkia przejmuje dekoracyjną rolę u podstawy krzewu w drugiej połowie sezonu, gdy kalina koreańska jest już niepozorna, i znosi półcień rzucany przez jej koronę.
Bad companions
Obie kaliny mają przeciwstawne wymagania wodne: koralowa rośnie na siedliskach wilgotnych i okresowo podmokłych, a koreańska wymaga gleby przepuszczalnej i na mokrym podłożu gnije. Stanowisko dobre dla jednej jest złe dla drugiej.
W głębokim cieniu i przy silnej konkurencji korzeniowej kalina koreańska kwitnie ubogo, słabiej przebarwia się jesienią i traci główny walor — intensywność zapachu zależy od liczby kwiatów.
The evidence level indicates whether the relationship is backed by research, observation, or gardening tradition.
Diseases and pests
A white, powdery coating on leaves, shoots and buds. The leaves turn yellow, become deformed and drop prematurely. The coating develops on both sides of the leaf blade, is often clearly visible from above, and can easily be rubbed off with a finger — it is the superficial mycelium of an ectoparasite that draws nutrients from the epidermal cells by means of feeding structures (haustoria). At first single, round, white spots appear, which in time merge and cover the entire leaf surface and the young growth. Young leaves and the current season's shoots are the most susceptible; heavy infection causes them to pucker, stiffen and stop growing, and on buds it leads to deformation or death of the flowers. On the fruit of some species (gooseberry, apple, cucurbits) the coating leaves russeting or a corky skin. Towards the end of the season, small, dark fruiting bodies (chasmothecia, formerly called cleistothecia) — the pathogen's overwintering structures — appear within the coating. The disease affects many plants, including roses, oak, privet, lilac, cucurbits, cereals, grapevine, apple, gooseberry, phlox and coneflowers, with each of these hosts being infected by a specialised species of fungus.
Armillaria root rot (honey fungus)The fungus attacks the roots and stem base of trees and shrubs, causing their slow decline – the plants grow weakly, the crown thins, the leaves become smaller, and eventually they dry up. The diagnostic sign is white, fan-shaped sheets of fungal mycelium forming a dense layer under the bark at the stem base, with a distinct mushroom smell. In the soil and under the bark there are black or dark-brown, bootlace-like rhizomorphs, by which the fungus spreads to further plants. In autumn, clusters of fruiting bodies – honey mushrooms – grow at the base of infected trees. The above-ground symptoms are non-specific and easily confused with drought or overfeeding: some plants die suddenly (the whole tree turns brown within a single season, especially in hot weather), while others weaken over years – producing short growth, discolouring prematurely, and just before death setting an exceptionally heavy crop of flowers or fruit ('stress flowering'). In conifers, resin bleeding at the stem base is common. When the bark is exposed at the root collar, the wood of the roots and stem turns white and softly rots – honey fungus causes a white rot of the wood. The mycelial layer can be cream-coloured and leathery, spreading radially from beneath the dead bark. A biological curiosity, rather than a sign useful in garden diagnosis, is that the mycelium in moist, infected wood can glow very faintly in the dark (so-called 'cold light') – the effect is too weak and requires complete darkness, so in practice it cannot be used to identify the disease. The disease advances in foci – neighbouring plants die off one after another around an infected one.
AphidsSmall (1–3 mm) soft-bodied insects, green, black or pink, feeding in clusters on young shoots and the underside of leaves. They excrete sticky honeydew. The diagnostic feature that distinguishes aphids from other small sucking insects is the pair of siphunculi (tubular projections) at the rear of the abdomen together with a tail-like cauda; a single colony usually holds wingless forms (parthenogenetic females) alongside winged migrants that fly onto new plants in summer. In summer aphids reproduce parthenogenetically and viviparously over many generations, so the population builds up explosively; in autumn many species produce a sexual generation that lays overwintering eggs on the host, and host-alternating species move between a winter host (often a tree or shrub) and a summer host (a herbaceous plant). Feeding symptoms include curling, crinkling and distortion of young leaves, stunted growth, yellowing, and the shedding of buds and fruitlets. Abundant honeydew coats the leaves, and the sooty mould fungus that develops on it forms a black film which limits photosynthesis; the honeydew is fed on by ants, which in return defend the colony against predators. Aphids are also important vectors of plant viruses (mosaics among them), transmitting them from plant to plant even during a brief probing puncture.
Toxicity
| For whom | Level | Notes |
|---|---|---|
| Humans | Mild | The fruit is not fit to eat - the RHS marks it as strictly ornamental and recommends gloves when working with the shrub. |
| Dogs | Mild | — |
| Cats | Mild | — |
History and origin
The species was described by William Botting Hemsley in 1888 (Journal of the Linnean Society, Botany 23: 350), based on material collected by William Richard Carles (1848-1929), a British consular official who travelled through Korea between 1883 and 1885 - his surname gives the specific epithet carlesii. Some horticultural sources give the year 1885, but the nomenclatural databases IPNI and POWO point to publication in 1888. The plant first came into cultivation in Japan, around 1897, through the firm L. Boehmer & Co. of Yokohama. The first specimen reached Europe in 1902, at the gardens at Kew, where it flowered in the open ground in 1906. Commercial spread in Europe began in 1905, when the Lemoine nursery bought up the stock of plants from the Boehmer firm. In the 20th century Koreanspice viburnum became the parent of three important hybrids, bred to combine its fragrance with greater vigour and health: Viburnum x juddii (with V. bitchiuense, William H. Judd, Arnold Arboretum, 1920), Viburnum x burkwoodii (with V. utile, Burkwood & Skipwith nursery, 1924) and Viburnum x carlcephalum (with V. macrocephalum f. keteleeri, the same nursery, around 1932). All three are sometimes described loosely in the trade as 'fragrant viburnums', which is a frequent source of confusion when buying.
Uses
Koreanspice viburnum is planted where its fragrance will actually be experienced: by the entrance to the house, along a path, next to a seating area, under a window opened in spring. Outside the flowering period the shrub is inconspicuous, which is why it rarely works as a specimen in the foreground - it does better in a mixed border, where other plants take over the second half of the season. Its slow growth and moderate size make it one of the few fragrant shrubs suitable for really small gardens and front gardens; dwarf cultivars tolerate cultivation in a large container. Spring-flowering bulbs do well at the base of the shrub, and ground-cover perennials after them. A few cut branches in full bloom are enough to fill a room with fragrance. When buying, it is worth checking whether the plant is grafted - grafted specimens throw up rootstock suckers, which have to be cut out regularly at ground level before they overgrow the noble part of the shrub. Plants raised from rooted cuttings do not have this problem.
Trivia
- Koreanspice viburnum is the parent of three well-known hybrids - Viburnum x juddii, V. x burkwoodii and V. x carlcephalum. None of them is a cultivar of this species, though they inherited their fragrance precisely from it.
- Commercial specimens are sometimes grafted onto a rootstock of wayfaring tree (Viburnum lantana). The rootstock grows much more vigorously than the scion and, if its suckers are not cut out, can over time dominate the shrub - the same mechanism is known from roses and ornamental apples.
- Despite its very intense fragrance the species is not a typical honey plant: the nectar hidden in the narrow corolla tube (about 8 mm) remains easily accessible mainly to butterflies, while bees use these flowers as a source of pollen instead.
Frequently asked questions
When should Koreanspice viburnum be pruned so as not to lose the flowers?
Only immediately after flowering, that is in May or early June. The flower buds for the following spring are set as early as summer, so pruning in autumn, winter or early spring removes the ready-made flowers of the next season. The shrub itself will not suffer from it, it simply will not bloom.
How does Koreanspice viburnum differ from the guelder rose?
They are two different species with different uses. Koreanspice viburnum is prized for the fragrance of its flowers, has broadly ovate leaves, a dense habit up to about 2.4 m and inconspicuous fruit, and needs well-drained soil. The guelder rose (Viburnum opulus) is native, has maple-like lobed leaves, grows to 4 m, has flowers without a distinct fragrance and bright red fruit that persists into winter, and grows on wet and seasonally waterlogged sites.
Where should Koreanspice viburnum be planted so that it smells its best?
Close to places where people spend time in spring: by the entrance, a path, a terrace or under a window. The fragrance is noticeable within a few metres of the shrub on warm, still days, so planting it deep in the garden wastes its main asset. The site should be sunny or lightly shaded - the more flowers, the stronger the fragrance.
Where do the strong, alien shoots at the base of the shrub come from?
Most often they are rootstock suckers. Koreanspice viburnum is sometimes grafted onto wayfaring tree (Viburnum lantana), which grows much more vigorously. Such shoots have different, distinctly wrinkled leaves and grow faster than the rest of the shrub - they should be cut out at ground level as soon as they appear. Plants propagated from rooted cuttings do not have this problem.
Does Koreanspice viburnum have ornamental fruit?
No. The drupes ripen in late summer from red to nearly black, but they set irregularly, are few and usually hidden among the leaves. Nor are they fit to eat - the RHS classifies them as strictly ornamental fruit. If you are looking for a viburnum with ornamental fruit that persists into winter, the guelder rose is a better choice.
Sources
- Plants of the World Online (POWO) — Viburnum carlesii Hemsl.Database (GBIF, POWO…)
- Missouri Botanical Garden, Plant Finder — Viburnum carlesiiInstitution / botanical garden
- Royal Horticultural Society — Viburnum carlesiiInstitution / botanical garden
- Trees and Shrubs Online — Viburnum carlesiiWebsite
My note
A private note for this plant — saved in your browser.
