Gardenesque

Plants Design Information Clay Soils Harford County, MD

Viburnums . . .
Shrubs for Three-Season Interest

From a design standpoint, Viburnums are an important genus of plants in the garden for several reasons:

they provide three seasons of interest (perhaps even four).
they provide flowers in the spring or early summer, berries in the summer, fall, and into winter, and attractive leaf colors in the fall. Many of them also have interesting leaves in the summer.
some are also fragrant.
I also like the fact that there are many species and cultivars to choose from so there is bound to be one or even two that fit a particular spot perfectly.
most of the viburnums work well as individual specimens or in groups or hedges.
smaller varieties can also be placed in foundation plantings.

They are also important for their ability to be used in many different cultural situations.

Depending on the species they can be planted in sun, part shade, or even in shady areas.
Some viburnums will grow in dry soil, while most will accept periods of drought during the summer after they have been established.

Listed below are the viburnums which will grow well in our area. Some species are in my garden now, others used to be, and still others are on my list of plants to purchase. It's very important to place a plant in the right spot so I've included specific information on the cultural conditions required for each species. The harder-to-find species (acerifolium, alnifolium, bitchiuense, macrocephalum, cassinoides, molle, lantana, lentago, obovatum, x rhytidophylloides, and seiboldii) are not included. Also, there are some viburnums that are not hardy where we live in Zone 6B of the Department of Agriculture Hardiness Zone Map. They are davidii, japonicum, awabuki, odoratissimum, suspensum, tinus and they are not listed here as well.

Basically, viburnums grow in moist, well-drained soil and in sun. After establishing a viburnum for a year or two, the plants will take some drought. Usually the plant will tell you by its droopy leaves when it needs water.

Here's the list of viburnum species, followed by the new "must-have" cultivars:

Burkwood Viburnum

x burkwoodii - Burkwood viburnum is not a species but the result of crossing two different species; therefore, the "x" is shown before its name. Grows to about 10x7ft. Its form or habit is upright and multi-stemmed. Leaves are elliptic, pointed, slightly serrated, and 4in long. Fall leaf color is wine red. The flower buds are pink. It has fragrant, white, snowball-type flowers. Its fruit starts red and then changes to black but usually the plant doesn't produce much fruit. (This is a cross between carlesii and utile; both are listed below.)

Fragrant Snowball

x carlcephalum - Fragrant viburnum grows to 10x10ft and its habit is open and loose. Leaves are dark green, broadly oval, wavy, pointed and up to 5in long. Fall leaf color is red purple. Its flower buds are pink. It has fragrant, snowball-type, white flowers up to 6in across. Its fruit starts red then changes to black. (This is a cross between carlesii and macrocephalum var. keteleeri.)

Koreanspice Viburnum

carlesii - Koreanspice viburnum (photo to left) grows to 6x6ft into a dense, rounded shrub. The leaves are a dull, dark green and a wide oval in shape. The leaves are slightly serrated, pointed and are 4in long. Flower buds are pink to red. Its fragrant, semi-snowball, white flowers are 3in wide. Fruit starts red and then changes to black.

carlesii

Arrowwood Viburnum

dentatum - Arrowwood viburnum is a native shrub occurring naturally in eastern North America. Grows to 10x10ft in a dense, rounded form. Its leaves are a lustrous dark green, broadly oval in shape and pointed. The leaf's margins are coarsely serrated. Fall color varies from shrub to shrub and could be yellow, red, or purple. Has white flat-topped flower clusters. Has oval blue or blue-black fruit relished by birds. This viburnum grows well in sun to part shade and will sucker with the plant growing wider with time.

Viburnum dentatum 'Christom' Blue Muffin

'Ralph Senior' - Autumn Jazz® has glossy green foliage that turns yellow-orange-red-burgundy in the fall. Grows to 10x12ft in a vase form.

'Cardinal' has consistent brilliant red fall color.

'Perle Bleu' produces heavy crops of blue fruits and grows to 10ft tall.

'Christom' - Blue Muffin™ (photo to right) also produces a heavy crop of intense blue fruits and grows to about 7x7ft.

Linden Viburnum

dilatatum - Linden viburnum (photo to left) grows to 10x8ft in an upright and open habit. Leaves are dark green, often lustrous, and a broad oval with coarsely-toothed leaf margins. The leaves are 4 ½in long and are not sharply pointed. Fall leaves are russet red. Has creamy-white, flat-topped flower clusters. This viburnum will grow in sun to part shade. Fruit is 1/3in long, red or scarlet, and very showy.

'Erie' (photo to right) grows to about 8x10ft wide and has good red to orange fall color. Its abundant red fruits turn coral to pink after frost and stay that way through the winter. It is very resistant to insects and diseases.

'Michael Dodge' has yellow fruit instead of the usual red and it grows to 5x6ft wide. Has red fall leaf color.

farreri Viburnum

farreri - This fragrant viburnum grows to 12x12ft in a loose, open habit. Its leaves are dark green, oval, with edges serrated and pointed. Leaves are 4in long. Flower buds are pinkish red. Has fragrant, white-tinged-with-pink flowers in a flat-topped flower cluster. It blooms before the leaves unfold which helps to make the flowers stand out. Fruit is red changing to black when it matures.

'Nanum' is a dwarf cultivar growing only to 3x6ft. It has pink flower buds and white flat-topped flower clusters. I grew this plant for several years but it was planted in the wrong place and it died recently. I'm willing to grow this one again because of its fragrance and size.

Judd Viburnum

x juddii - Judd viburnum is said to be a superior carlesii with a full and rounded habit. Grows to 8x8ft. Leaves are dark green, oval to round, slightly serrated, pointed and 4in long. Its flowers are white, fragrant, and snowball-type. Its red fruit changes to black. (carlesii x bitchiuense)

Smooth Witherod Viburnum

nudum - Smooth Witherod viburnum (photo to left) is a native shrub found in eastern North America. It grows to 10x10ft in an upright form. Has lustrous, dark green, elliptic, pointed leaves. Its fall leaves are red to red purple. Has creamy-white flowers in a flat-topped flower cluster. Its fruit is red to purple.

'Winterthur' (photo to right) is my favorite nudum cultivar with lustrous, dark-green leaves and beautiful pink to blue fruit with the different fruit colors appearing at the same time. This is an upright plant and is said to be about half the size of the species.

European Cranberrybush

opulus - European Cranberrybush grows to 15x15ft in a multi-stemmed, arching habit giving the overall impress of a rounded shrub. Plant in sun or part shade. Its leaves are glossy, dark green, deeply lobed, and grow to 4in long and wide. The fall foliage is variable being yellow-red or red-purple. Has white lacecap-type flowers with white, fertile, inner flowers and showy, outer, sterile flowers in flat-topped flower cluster. Its fruit is bright red.

'Leonard's Dwarf' - this is another compact plant very similar to 'Compactum'.

'Nanum' (photo to left) is a great, small, low-maintenance deciduous shrub that should be used more than it is. Grows to 2x3ft wide. This is a non-flowering and non-fruiting plant. Mine has never flowered. Makes a nice low hedge or accent plant among flowers or ground covers, and grows in bright shade.

Japanese Snowball

plicatum - Japanese Snowball grows to 15x15ft in an upright form. Has dark green, broad oval, ridged leaves coming to a sharp point. White sterile flowers are formed into a rounded, snowball-type cluster.

'Kern's Pink', 'Pink Sensation', and 'Roseace' - have pink snow-ball type flowers on a 6ft plant. I saw 'Kern's Pink' on a recent garden trip and thought it was a worthwhile plant to have in the garden because of the unusual pink flowers for a viburnum.

Doublefile Viburnum

plicatum var. tomentosum - Doublefile viburnum grows to 9x12ft in a horizontal form. Its leaves are dark green and broadly oval and have a sharp point. Its flowers are non-fragrant, pure white, lacecap-type flowers with white, fertile, inner flowers, and large, outer, sterile flowers in a flat-topped flower cluster. Has red-purple fall leaves and red fruit changing to black. Fruit is very showy and devoured by birds during the summer. As it grows large, one way to control its size is to cut it back very hard every few years. My shrubs are left to grow to their natural size so you can see their beautiful horizontal form.

'Shasta' is a very popular cultivar. It's wider than tall - 6x12ft wide. Its lacecap-type flowers are 6in wide. The fruits are red changing to black as they mature.

'Watanabei' is another smaller growing doublefile. Its habit is dense and it flowers on and off through the summer too.

Viburnum plicatum var. tomentosum The Doublefile viburnum (photo to right) is for me the star plant of the viburnums. It looks like a dogwood when in bloom. It is stunning in the spring with its beautiful white flowers growing on wide, horizontally tiered stems. After flowering, the show goes on with its showy red fruit sitting on top of its wide stems just waiting to be eaten by birds. In the fall it again puts on a beautiful display when the leaves turn dark red.

Blackhaw Viburnum

prunifolium - Blackhaw viburnum is a native shrub growing in eastern North America. Grows to about 15x12ft in an upright to rounded form. Its leaves are broadly oval and pointed, dark green in color, and grow to 3.5in long. Its flowers are creamy white and are in a flat-topped flower cluster. Fall leaves are purple to red. Its edible fruit is pink changing to blue black. Plant in sun or shade; it is adaptable in its soil requirements including dry soil.

Prague Viburnum

x pragense - Prague viburnum grows to 10x10ft and its habit is upright to oval. It is said to be extremely fast growing and needs pruning to keep it dense. Its evergreen, lustrous, dark green, oval leaves are 4in long. Flower buds are pink. Slightly fragrant creamy-white flowers are in a flat-topped flower cluster. (This is a cross between rhytidophyllum and utile).

Leatherleaf Viburnum

rhytidophyllum - Leatherleaf viburnum grows to 15x15ft in an upright, multi-stemmed habit. Its evergreen, long, narrow, dark green, leathery leaves are rough and grow to 7in long. Leaves are only slightly pointed. Its flowers are lightly fragrant, creamy-white in a flat-topped flower cluster. Its fruit starts red and changes to black. This viburnum tolerates heavy shade but needs protection from wind.

'Cree' is more compact than the species and has lustrous, dark-green leaves growing to about 6in long. Cree grows to about half the size of the species and the leaves do not curl or roll in the winter as in the species. It produces lots of flowers and red fruit.

Sargent Viburnum

sargentii - Sargent viburnum grows to 15x15ft in a multi-stemmed, upright to rounded form. Its green, strongly-lobed, maple-like leaves are up to 5in long and have a smooth, leathery texture. Fall leaves are yellow to red. Has white lacecap-type flowers with white, fertile, inner flowers and large outer, sterile, flowers in a flat-topped flower cluster. Its fruit is translucent bright red. It's a vigorous grower and is more resistant to aphids than European Cranberrybush .

Once I saw the two-color lacecaps on 'Onondaga' I had to have one for my very own. Luckily I found one soon after and have been enjoying its smooth, lustrous leaves ever since. It was too young to flower when I planted it. Hopefully it will flower next year. Actually, even if it doesn't ever flower, I will enjoy it any way because its smooth leaves are enjoyable to touch.

Tea Viburnum

setigerum - Tea viburnum (photo to right) grows to 12x9ft in an upright, multi-stemmed form. As the plant matures it takes on a weeping habit which is very beautiful when properly placed in the landscape. It has narrow oval, pointed, lustrous, dark-green leaves to 6in long. Leaves turn a dark red purple in the fall. Has creamy-white flowers in a flat-topped flower cluster. The flowers are secondary to its showy bright, warm-red fruit which lasts into the winter because the birds don't eat the fruit right away.

Several plants of this species are planted at the top of a hill with ground cover underneath. Hilltop siting is best because the stems eventually arch over and since we are looking at the plant from below, we see a gorgeous spectacle in the fall and winter with the cascading plants laden with bright red berries. Give it plenty of room and never cut back its stems as you will be destroying this plant's beauty. As it ages, and as with most all deciduous plants, cut one-third of the oldest stems back to the ground each year before new growth starts. In this way, there will always be fresh, new growth with plenty of fruits for viewing and for the birds.

American Cranberrybush

trilobum-American Cranberrybush (photo to left) is a native shrub naturally found in eastern North America. It grows to 12x12ft in a dense, rounded form. Its lustrous, medium-to-dark-green, lobed, maple-like leaves come to sharp points. Fall leaf color is yellow to red purple. Its flowers are lacecaps with white, inner, fertile flowers and white, outer showy, sterile flowers in a flat-topped flower cluster. Its fruit is bright red and very showy.

'Red Wing' is smaller growing to 8x8ft. It has reddish new leaves and red leaf stems, or petioles, which remain throughout the season. In the fall the leaves turn bright red to wine colored. The bright red fruits are persistent through the fall and winter.

'Compactum' is a compact cultivar that is just perfect for smaller gardens because it grows only to half the size of the species.

'Bailey Compact' is another smaller-sized cultivar that has a deep red fall foliage and grows to about 5x6ft wd.

Viburnum Characteristics

Also, all viburnum species have similar characteristics that show that they are related to each other. The first one is that they all have "simple" leaves with a leaf bud appearing at the point or "axil" where the each leaf is attached to the stem. Other examples of "simple" leaves are maple, beech, and oak. See example:

Another characteristic of all viburnums is that two leaves are "opposite" meaning that the leaves and their buds are directly across from each other on the stem. See example.

Another characteristic is the shape of the leaf which in viburnums tend to be "ovate" or "elliptical". And yet another characteristic is that the margins or edges of the leaves tend to be "serrate", "incised", "undulate", or "lobed". That means the leaves have many points like a saw or serrated knife.

cyme-type flowers As to flower shape, all viburnums have a "cyme" type flower configuration which is a wide-spreading group of small and/or large flowers at the end of the flower stalk with the inner flowers opening first. Dogwoods and viburnums are examples. The cymes are either snowballs or semi-snowballs (similar to the summer-blooming PeeGee Hydrangeas), lacecaps (as in the flat-topped hydrangeas such as "Tokyo Delight" with tiny, fertile flowers in the center and larger, showy, sterile flowers on the outside), and flat-topped flower clusters made up of all tiny, fertile flowers.