All the viburnums are garden worthy shrubs with all season interest, but this one, the first I had ever grown, remains my favorite. It is open and graceful, while generously free with its sweet fragrance in the spring. In my present garden it survives while looking wonderful in a very shady spot near the house and under trees. When I grew it formerly in the sunniest spot on the west side of a city house, it was even better.
This viburnum can take a great deal of pruning to stay within a specific space, or as an espalier. It will give you medium sized balls of creamy white, fragrant (thus the designation “spice”), 2″ to 3″ cymes of flowers in the month of April. The foliage is a grayish medium green, a bit dusty for the remainder of the summer (actually more attractive than that makes them sound), but in early fall ovate rosy berries show, and the foliage takes on tints of coral, while the berries then turn a dark black red. Overall, a pretty good show.
As noted, it likes afternoon sun, but will tolerate shade and still bloom, albeit in the upper parts of the bush which will receive the best light. the preference is for rich, moist soil and full sun. However, it takes a wide range of soil conditions and isn’t fussy. Hardy to zone 4. Widely vase shaped and very open when grown naturally. Grows 5′–6′ high to 5′ wide, although it can get larger. Blooms late March through April depending on situation; here, it blossoms in April. Reputed to need “summer days with high heat”, it certainly receives that here in the Midwest.
A word about fertilizers: if spring blooming shrubs are fertilized too heavily they may not flower well.
I have found all my viburnums to grow larger than the heights and widths given in most garden literature. while V.carlesii responds well, and looks good, to severe pruning, that cannot be said for many of the other types.
Key cultivation information for Viburnum Carlesii
- pH: various
- hardiness: zones 4 to 7
- sun to part shade
- moisture: moderate, but will take dryness when well established
- slow growth rate
- heat tolerant
- use well balanced fertilizer, sparingly
- blooms: spring, white tinged with pink
- berries: fall
It is not without problems, although I personally have not experienced any. Problems listed:
Viburnum beetle, gray mold (Botrytis), rust, downy mildew, powdery mildew, wood rot, Verticillium wilt, leaf spots, and dieback. Aphids, scale insects, weevils, Japanese beetles, mealybugs, and tree hoppers.*
Origin: Korea, Japan
Besides the beautifully intoxicating aroma, Koreanspice viburnums attract butterflies (but you have to allow the caterpillars to feed), and the berries attract and feed songbirds. The leaves color up nicely in the fall, and it is a gracefully formed shrub.
Presently I am growing English ivy and lily of the valley (Convallaria majalis) underneath. All these plants are competing with greedy maple roots. If the conditions were more ideal, with sunshine and organic material amending the soil beneath, I would grow an array of little bulbs, followed by true geraniums of either the harmonious Geranium ibericum ‘Johnson’s Blue’ or more intense hybrid ‘Rozanne’. Those should match up with some autumn tints of rosy red, as well. The lily of the valley give a contrasting golden fall color, and extend the joy of fragrance in the springtime. I also have Aquilegia canadensis interspersed in this group and it is very lovely with the Korean spice bush, wholly different in flower form and giving a light gracefulness.