How to plant viburnum?

CAROLYN’S SHADE GARDENS

Carolyn’s Shade Gardens is a retail nursery located in Bryn Mawr, PA, specializing in showy, colorful, and unusual plants for shade. The only plants that we ship are snowdrops and miniature hostas. For catalogues and announcements of events, please send your full name, location, and phone number (for back up use only) to [email protected] Click here to get to the home page of our website for catalogues and information about our nursery and to subscribe to our blog.

The very showy flowers of redvein enkianthus, Enkianthus campanulatus ‘Princeton Red Bells’.

My nursery specializes in herbaceous flowering plants for shade. However, although no shade garden is complete without trees, shrubs, and vines, our local nurseries seem to ignore woody plants for shade. To fill this gap, I offer shade-loving woodies from a wholesale grower whose quality meets my exacting standards. To view the catalogue, click here. As in Woody Plants for Shade Part One, I thought my blog readers who are not customers might be interested in learning about the woody plants that I would recommend they add to their shade gardens. And doing an article in addition to the catalogue allows me to add more information so customers might be interested also.

Included in my offering are six shrubs and two vines. Of the eight plants I have chosen, five are native. Please read my article My Thanksgiving Oak Forest to see why I think planting native plants is crucial to our environment. My article New Native Shade Perennials for 2011 explains why I think native cultivars are valuable native plants. With that introduction, here are the plants I am highlighting:

Native bottlebrush buckeye, Aesculus parviflora

Native bottlebrush buckeye is a wonderful shrub for making a majestic stand in full shade. I grow it deep in my woods, and it performs beautifully. It grows to 10’ tall in full sun to full shade in any location and soil type. It is also deer resistant. The creamy white flowers on long upright brush-like panicles in early summer and the bold textured leaves give it a dramatic tropical look. It has excellent yellow fall color and attracts hummingbirds.

The lovely yellow fall color of bottlebrush buckeye.

Bottlebrush buckeye is native to parts of the eastern US, including Pennsylvania. It is a Pennsylvania Horticultural Society Gold Medal Plant, click here for details. It is also a Missouri Botanical Garden Plant of Merit, click here for details (photos courtesy of the Missouri Botanical Garden Plant Finder).

Dwarf slender deutzia, Deutzia gracilis ‘Nikko’

‘Nikko’ dwarf slender deutzia is another shrub that can grow anywhere from full sun to full shade and is deer resistant. In April and May, it is covered with delicate white flowers, and the fine-textured and neat green leaves turn purple in the fall. This deutzia makes an excellent specimen, growing 2’ tall by 5’ wide, or a superior flowering groundcover for shade. I grow it in full shade at the base of my winterberry hollies. It is native to Japan and is a Pennsylvania Horticultural Society Gold Medal Plant, click here for details.

I use ‘Nikko’ dwarf slender deutzia as a groundcover in full shade under winterberry hollies.

Redvein enkianthus, Enkianthus campaulatus ‘Princeton Red Bells’

In May ‘Princeton Red Bells’ redvein enkianthus is covered with a multitude of spectacular deep red, pendant bell-like flowers. Its elegantly arranged blue-green leaves turn an excellent dark red in the fall. It has a very unique and graceful habit (see photo of species below) and grows to 8’ tall by 4’ wide in full sun to full shade. It is deer resistant and likes average to moist soil, although I grow it in my dry woodland. It is native to Japan. For more information about the species, click here.

This photo of the straight species of redvein enkianthus growing in my woodland shows its elegant habit and abundance of flowers. The flowers of ‘Princeton Red Bells’ are much more eye-catching.

The amazing flowers of native smooth hydrangea, Hydrangea arborescens ‘Annabelle’.

Native ‘Annabelle’ smooth hydrangea has won numerous awards for its very showy, huge (up to 1’) snowball flowers, which appear from June into September. It grows 5’ tall by 5’ wide in part to full shade (full sun is not recommended). It is supposed to be deer resistant for a hydrangea. A gentle pruning in late spring produces optimum growth.

‘Annabelle’ produces copious, long lasting flowers.

Smooth hydrangea is native to the eastern U.S., including Pennsylvania. It is a Pennsylvania Horticultural Society Gold Medal Plant, click here for details. It is also a Missouri Botanical Garden Plant of Merit, click here for details (photos courtesy of the Missouri Botanical Garden Plant Finder).

The gorgeous and delicious fruit of native northern highbush blueberry, Vaccinium corymbosum ‘Jersey’.

Gardeners might not think of northern highbush blueberry as an ornamental, but it has everything you could want in a shrub. Its pretty bell-shaped white flowers appear in May and are followed by delicious and beautiful powder blue fruit in summer. It has excellent scarlet fall color and is native and wet site tolerant. What more could you ask for? It grows to 6’ tall in full sun to part shade.

The flowers of northern highbush blueberry

Northern highbush blueberry is native to all of eastern North America, including Pennsylvania. I am offering two cultivars: ‘Jersey’ is an early midseason producer, and ‘Berkley’ is late midseason. Planting two different cultivars produces better fruit. For more information, click here (photos of berries and fall color courtesy of the Missouri Botanical Garden PlantFinder).

The fall color of northern highbush blueberry.

Doublefile viburnum, Viburnum plicatum var. tomentosum

My doublefile viburnum, pictured above, is one of the showiest and most talked about plants in my display gardens. ‘Mariesii’ is a superior cultivar of doublefile viburnum. Its large, white lacecap flowers in May and June and elegant, pleated medium green leaves are an unbeatable combination. It grows quickly up to 12’ tall and 10’ wide in part to full shade and is deer resistant. It is native to China and Japan. For more information, click here.

The flowers of doublefile viburnum.

Native trumpet honeysuckle, Lonicera sempervirens ‘Crimson Cascade’

Native ‘Crimson Cascade’ trumpet honeysuckle produces bright coral red tubular flowers that invite hummingbirds from miles around in late spring and reblooms through fall. Its shiny dark green leaves with red stems remain attractive through the season. It is native to all of eastern North America, including Pennsylvania. I grow mine mixed with my wisteria on my front porch and in an even shadier location along my front stairs.

Trumpet honeysuckle climbs my Chinese wisteria and blooms before, during, and after the wisteria is done.

Native American wisteria, Wisteria frutescens ‘Amethyst Falls’

The copious fragrant, lavender-blue flower clusters of ‘Amethyst Falls’ American wisteria are almost as beautiful in bud as in bloom from June to August. This wisteria has fine-textured attractive foliage and is less rampant than Asian wisteria. It grows to 20′ at maturity in full sun to part sun (it is technically not a shade plant). It is native to the eastern U.S., including Pennsylvania. ‘Amethyst Falls’ is a Pennsylvania Horticultural Society Gold Medal Plant, click here for details.

The flowers and foliage of American wisteria.

I grow every one of these shrubs and vines in my gardens so I know you can’t go wrong by adding them to yours! If you are a customer, you have until May 25 to place an order by clicking here. If not, now you have some plants to ask for at your local independent nursery.

Carolyn

Notes: Every word that appears in orange on my blog is a link that you can click for more information. If you want to return to my blog’s homepage to access the sidebar information (catalogues, previous articles, etc.), just click here.

Nursery Happenings: Orders for woody shade plants will be accepted until noon on Wednesday, May 25. We will have our traditional open hours over Memorial Day Weekend on Saturday from 9 am to noon and Sunday from noon to 3pm. You don’t need an appointment, just show up. But remember you can make an appointment to shop 24/7 by sending me an email at [email protected] There is still a great selection of hostas, ferns, and hardy geraniums.

Viburnums: Shrubs with Four Season Interest

Viburnums are some of the most attractive, versatile, adaptable shrubs for the home landscape. They can be used as hedges or screens as well as in mixed perennial/shrub borders, but they can also stand alone as specimen plants. They usually take the form of shrubs, but some species can become spectacular small ornamental trees. They range in size from the Dwarf American Cranberrybush at 2 feet tall by 2 feet wide, to the Wayfaring Tree at 12 feet tall and 10 feet wide.

Viburnums are plants with four seasons of interest. All Viburnums have profuse white to pink flowers in the spring. They have large, attractive and often highly textured leaves. Showy midsummer berries are an important food source for birds. Colorful red to purple leaves in the fall persist well into the winter, when Viburnums’ dramatic branching structure is revealed and enhanced by a dusting of snow.

But the best feature of Viburnums is their adaptability. While they would prefer full sun and moderately watered, well-drained rich soils, they are not picky and most (unless otherwise noted in the table below) will grow very well in part shade in alkaline, clay soils. Diseases and pests rarely attack them. Their fibrous root system makes them very easy to transplant.

If you are searching for a good-looking hardy shrub or small tree for sun or partial shade, consider one of the many members of the Viburnum family.

Viburnums:
Name Ht/Width
Zone
Shape
Arrowood Viburnum
Viburnum dentatum
6-8 ft/ 6-8 ft
zone 2
Rounded Multi-stem dense, round shrub with narrow arching branches.
Wayfaring Tree
Viburnum lantana
10-12 ft/8-10 ft
zone 3
Upright rounded Can be shrub or small tree. Great blue-green leathery foliage. Burgundy red fall color.
Mohican viburnum Viburnum lantana ‘Mohican’ 8-9 ft/ 8-9 ft
zone 3
Rounded Variety of V. lantana selected for it’s more compact form.
Nannyberry Viburnum Viburnum lentago 12-14 ft/ 8-12 ft
zone 2
Upright rounded Glossy green foliage turns brilliant orange red in fall. Can be shrub or small tree.
Compact European Cranberrybush Viburnum opulus ‘Compactum’ 4-5ft / 5-6 ft
zone 3
Rounded Light green foliage turns purplish red in fall. Great small shrub for mass plantings and seasonal interest
Dwarf European Cranberrybush
Viburnum opulus ‘Nanum’
1-2 ft / 1-2 ft
zone 3
Compact rounded Extremely dense compact shrub.
Allegheny Viburnum Viburnum x rhytidophylloides ‘Allegheny’ 8-10 ft/ 8-10 ft
zone 4
Rounded Wrinkled leaves have a nice texture.
Onondaga Viburnum
Viburnum sargentii ‘Onondaga’
6 ft/ 6 ft
zone 3
Rounded Foliage emerges a velevty maroon, maintaining a maroon tinge when mature. Pale purple flowers. Needs more moisture than other Viburnums.
American Cranberrybush
Viburnum trilobum
10-12 ft/ 8-10 ft
zone 2
Broad upright ‘Wentworth’ cultivar selected for profuse flowering and fruit with excellent flavor, ideal for preserves.
Red fall color. Full sun.
Compact American Cranberrybush
Viburnum trilobum ‘Compactum’
4-5ft/ 4-5 ft
zone 2
Rounded Light green grape-leaf shaped Foliage turns dark red in fall Dense shrub adds visual interest in winter.

April – May 2002: Viburnums: Shrubs with Four Season Interest | Discouraging Canada Geese | Yellowjacket Control—Now is the Best Time to Do It | Growing Orchids

Snowball viburnum or guelder-rose is a very beautiful shrub, much appreciated in our gardens for its appealing blooming.

Main snowball facts summary

Name – Viburnum opulus
Family – Caprifoliaceae (honeysuckle family)
Type – shrub

Height – 6 ½ to 16 feet (2 to 5 meters)
Exposure – full sun or part shade
Soil – ordinary, well drained

Foliage – deciduous
Flowering – April to June

Planting, caring for it and pruning contribute a lot to the proper growth of the snowball viburnum.

Planting snowball viburnum

Preferably in fall or spring for specimens purchased in pots or in containers.

  • Follow our advice on planting shrubs.

For the first few years after planting, feel free to water now and then to ensure proper settling in and guarantee the growth of the shrub.

To multiply your viburnum, wait for the end of summer and prepare cuttings from semi-hardened wood, or simply perform layering.

Pruning snowball viburnum

It isn’t really a requirement to prune.
Wait for the blooming to end if you wish to reduce or reshape the shrub.

  • Find our advice on pruning shrubs.

All there is to know snowball viburnum

The ‘Snowball’ viburnum, also called guelder-rose, is a very beautiful shrub which has a blooming as magnificent in spring as its foliage is in fall.

As part of a flowered hedge, as a standalone or in shrub beds, its growing and maintenance is easy.

Also part of the Viburnum family is laurestine or Viburnum tinus which is often found in our gardens, as well as ‘Watanabe’ doublefile Japanese snowball which has a blooming that lasts for a very long time, from May to October.

Smart tip about snowball

Avoid locations that are too exposed to harsh sun.

How To Tell Snowball Bushes Apart: Is It A Snowball Viburnum Bush Or Hydrangea

The problem with using common plant names instead of the tongue-twisting Latin names that scientists assign them is that similar-looking plants often wind up with similar names. For instance, the name “snowball bush” can refer to a viburnum or a hydrangea. Find out the difference between viburnum and hydrangea snowball shrubs in this article.

Snowball Viburnum vs. Hydrangea

The old-fashioned snowball bush (Hydrangea arborescens), also called Anabelle hydrangea, produces large clusters of flowers that start out pale green and turn white as they mature. The Chinese snowball viburnum bush (Viburnum macrocephalum) is similar in appearance and also produces flowers that start pale green and age to white even though the two plants aren’t related. If you’re wondering how to tell snowball bushes apart, take a look at these characteristics:

  • Snowball hydrangea shrubs grow 4 to 6 feet (1.2 to 1.8 m.) tall, while the viburnums grow 6 to 10 feet (1.8 to 3 m.) tall. If you’re looking at a shrub that is well over 6 feet (1.8 m.) tall, it is a viburnum.
  • A snowball viburnum bush won’t tolerate a climate colder than U.S. Department of Agriculture plant hardiness zone 6. Snowball bushes growing in colder climates are probably hydrangeas.
  • The hydrangeas have a much longer bloom period than the viburnums, with blossoms remaining on the shrub for as long as two months. Hydrangeas bloom in spring and may rebloom in fall, while viburnums bloom in summer.
  • Hydrangeas have smaller flower heads that seldom exceed 8 inches (25.4 cm.) in diameter. Viburnum flower heads are 8 to 12 inches (25.4 to 30 cm.) across.

These two shrubs have similar requirements: they like light shade and moist but well-drained soil. Viburnum can tolerate drought in a pinch, but hydrangea is insistent about its moisture.

The big difference is in the way the two shrubs are pruned. Cut hydrangeas back hard in late winter. This encourages them to come back lush and leafy in spring. Viburnums, on the other hand, need pruning right after the flowers fade. If you wait too long, you could lose next year’s beautiful flush of flowers.

Hybrid leatherleaf viburnum

Size & Form

An upright, spreading shrub reaching 8 to 10 feet high and wide.

Tree & Plant Care

Best in full sun to part shade out of direct wind
Mulch provides cooler root environment and conserves moisture.
Flowers on old wood, prune after flowering
May have dieback in harsh winters

Disease, pests, and problems

No serious problems

Native geographic location and habitat

Of hybrid origin; cross between Wayfaringtree (Viburnum lantana) and leatherleaf viburnum (Viburnum rhytidophyllum).

Leaf or needle arrangement, size, shape, and texture Hybrid leatherleaf viburnum leaves photo: John Hagstrom

Opposite, 4 to 6 inches long elliptical shaped leaves
Dark green with a leathery, rugose texture
Semi-evergreen in the southern end of its range; deciduous in the northern climate
No fall color, but leaves will stay on the plant late into fall.

Flower arrangement, shape, and size

Small, creamy white flowers in 3 to 4 inch, flat-topped to slightly domed clusters

Fruit, cone, nut, and seed descriptions

Berry-like fruits (drupes); red maturing to black
Requires other viburnums near by for pollination to promote good fruit production.

Cultivars and their differences

Alleghany hybrid leatherleaf viburnum (Viburnum x rhytidophylloides ‘Alleghany’): Large, dense 10 to 12 feet high, rounded habit; very dark green leathery leaves; flowers and fruits more abundantly. More cold hardier than hybrid parents.

Willowwood hybrid leatherleaf viburnum (Viburnum x rhytidophylloides ‘Willowwood’): A 10 to 15 feet high and 10 feet wide, rounded shrub with arching branches; dark green leathery foliage; cold hardy in the Midwest.

How to Care for an Alleghany Viburnum

red rowan image by Marek Kosmal from Fotolia.com

The Alleghany viburnum (Viburnum rhytidophylloides Alleghany) is an upright evergreen to semi-evergreen shrub with dense foliage and a rounded shape. Alleghany viburnums bloom during spring with large clusters of white, fragrant flowers. This shrub grows rapidly to 10 feet tall and wide, making it an excellent shrub for creating privacy screens, hedges and windbreaks. The Alleghany viburnum also produces red ornamental, berry-like fruits that emerge reddish in color and turn to black. Alleghany viburnums are low-maintenance shrubs that provide year-round interest and beauty. This shrub grows best in USDA hardiness zones 5 through 8, where winter temperatures rarely dip down to minus 15 degrees Fahrenheit.

Water your Alleghany viburnum deeply to soak the soil down to and around the roots once each week during summer when rainfall is less than 1 inch. During the first year after planting the viburnum, water once each week to thoroughly soak the soil regardless of rainfall.

Spread a 1-inch-thick layer of organic compost on the ground around the Alleghany viburnum each year in early spring, spreading the compost to cover the entire canopy area. Instead of compost, you can apply an all-purpose tree and shrub fertilizer before new growth emerges in spring, following the dosage instructions on the label.

Spread a 2-inch-deep layer of mulch on the ground around the Alleghany viburnum to control weeds and preserve soil moisture. Add fresh mulch each spring to maintain the layer’s thickness and extend the mulch over the entire root area.

Prune away all damaged, dead or diseased branches throughout the year. Cut these branches back to the crotch at the main trunk, and avoid removing more than one-third of the Alleghany viburnum’s canopy in a single season.

Prune to shape your Alleghany viburnum each year immediately after the bush finishes flowering. You can shear the shrub to shape it or perform selective pruning and trimming of individual branches.

Fertilizer for Viburnum

Arrowwood image by Valeriy82 from Fotolia.com

Viburnums are hardy, low-maintenance shrubs suitable for most climates in the United States. They produce showy, white blossoms in the spring, followed by glossy green leaves in the summer. Many viburnums produce berries and brilliant fall foliage. Viburnums generally have a dense, rounded growth habit, making them a good choice for a privacy screen. Grown as a mass planting or a single shrub, they provide beauty to almost any landscape.

Considerations

Viburnums are hardy shrubs, requiring little fertilizer. In fact, unless a soil test has indicated a soil deficiency, gardeners may not need any fertilizer, which is preferable to overfertilizing, according to the University of Rhode Island Landscape Horticulture Program. Viburnums grow best in slightly alkaline soils (7.0). Gardeners may treat acidic soil with lime, based on recommendations from a soil test, to raise the pH level.

FertilizerTypes

Gardeners may use a commercial fertilizer, such as a granular 18-6-2 or 24-6-12 formula, if desired. However, many commercial fertilizers provide more nitrogen than viburnums need, according to Washington State University Botanical Gardens, sacrificing blooms and fruit for excessive foliage. Mulches of compost, manure, alfalfa pellets or fish fertilizers improve the soil while feeding the plants.

Time Frame

Gardeners may apply a compost mulch fortified with fish meal in the fall, after the first frost but before the ground is frozen, to support good root growth. A second application of fertilizer is applied in the spring. A few shovelfuls of compost or rotted manure, combined with fish or alfalfa meal, will provide nutrients for rapid growth.

Viburnum Care

Viburnums are planted in spring or fall and bloom best in full sun, although many tolerate partial shade. They prefer evenly moist, well-drained soils. A 2-inch layer of wood chip mulch keeps soil moist and prevents weed growth. Viburnums rarely need pruning to shape them, although gardeners can revitalize old viburnums by cutting dead, old growth to the ground in early spring before new growth emerges. Most viburnums are large shrubs, standing 8 to 12 feet high and almost as wide. Gardeners should plant them in a location that will provide adequate space.

Varieties

More than 150 species of viburnum exist, according to “Fine Gardening” magazine, and grow in USDA plant hardiness zones 2 through 9. American Cranberry Bush (Viburnum trilobum) is a popular variety that reaches 10 to 12 feet high. It produces bright red clusters of berries in the fall. Judd viburnum (Viburnum juddii) is a smaller bush, reaching 6 to 8 feet high and almost as wide. It has fragrant, white blossoms in spring and fuzzy leaves that turn purple or red in the fall.

Caring for Viburnum

The care information provided in this section represents the kind of practical advice is available for all the plants in this web site if you subscribe to the monthly customized newsletter Yardener’s Advisor.
Watering
Viburnums do not usually need watering except when they’re first planted, in time of drought, or in late fall before the ground freezes for the winter. If you do water, give your plants 1 gallon of water twice a week or run your drip irrigation system or sprinkler for 20 to 30 minutes twice a week. Older shrubs need watering only during severe drought.
For more information see file on About Watering Equipment.
Fertilizing
These shrubs need only one yearly application of bagged sludge, a granular fertilizer with a slow release form of nitrogen, or compost. In the fall, spread a 10-10-10 fertilizer on the soil to 1-1/2 feet beyond the tips of the branches (drip line). You may wish to supplement the fall feeding with 2 or 3 monthly snacks in late spring and early summer. Use a light side dressing of granular fertilizer or apply a foliar spray of dilute liquid fertilizer over all the leaves of the plant.
For more information see file About Fertilizers.
Consider Plant Growth Activators
There are on the market a growing number of products that will help your plants become healthier, more drought resistant, more disease resistant, and even more insect resistant. These products are generally easy to use and not terribly expensive. If you want to give your plants some oomph, check out New Technology In Plant Growth Activators
Mulching
Viburnums do best when they have a 2- to 4-inch layer of organic mulch over their root zone all season long. Keep the mulch about 6 inches away from the trunk to avoid decay and rodent damage. Use chopped leaves, pine needles or wood chips to mulch viburnum. Avoid mulching with un-chopped leaves because they mat together, preventing water from getting into the soil. Peat moss makes poor mulch, because it draws water from the soil like a wick and is difficult to rewet when dry.
For more information see file on Using Mulch.
Pruning/Grooming
Healthy specimens rarely need pruning. Prune Viburnums after flowering only if pruning is necessary for shaping. Old or crowded plants may be thinned and shortened to bring flowers to eye level. After 4 to 5 years you may remove 1/3 of the oldest stems, and thereafter prune every 2 or 3 years. For a more formal effect, it is possible to train Viburnums to a single trunk. Choose the healthiest and most upright stem when young and keep side shoots pinched until it reaches the height you want. Then allow the plant to branch from the top.
For more information see files on Pruning Shrubs and Choosing Pruning Tools

Guelder-Rose is one of the many names of this shrub filling every garden and balcony with a wonderful flowerage. In fall, it brings fresh color to an increasingly dull environment with its berries. The perennial plant is hardy and will thrive for many years if you create a few conditions for it which are explained in detail in this care instruction for the Viburnum opulus.

Plant Profile

  • family: Adoxaceae
  • genus: Viburnum
  • species: Viburnum opulus
  • popular Names: Guelder-Rose, water elder, cramp bark, snowball tree and European cranberry bush
  • origin: Eurasia and Northern Africa
  • persevering perennial plant
  • growth height: between 1.5 meters up to 6 meters
  • flowering period: from May to June
  • flower color: crème- to pinkish-white
  • red berries in fall
  • reddish orange leaves in fall

Only on rare occasions, you will meet such a robust, blossoming shrub like it is the case with this viburnum species “Snowball Tree”. It is suited best for garden friends and plant lovers which only just have discovered their passion or would like plants without having to put in lots of working hours.

The winter hard plant will make it easy for you in every situation. Read in our care instruction what you must keep in mind when planting, caring, multiplying and overwintering.

Care

The water elder or snowball tree presents itself as an example of low maintenance and even laymen will be able to cater it its needs. You can find orientation with the following care instructions and you will have years of joy derived from this garden plant.

Location

The snowball tree feels most comfortable in a sunny to semi-shaded location. But it does neither do well with direct sun light nor with blazing midday sun. Optimal would be a place where the morning and evening sun will shine on it.

It shows to normally be quite robust when it comes to wind. But especially the young plants have issues with cold draft air during the winter months. Therefore, it should be places a little sheltered from the wind.

Additionally, choose a place without constant moisture which would for example be the case at shores, ponds or creeks. Also, being located next to plants with a high demand for water is not ideal. It could lead to overmoisturing and the snowball tree might react to it with root decay.

Soil Conditions

For optimal living conditions, the soil conditions are very important. For this reason, the soil needs to fulfill certain prerequisites so that the snowball tree feels comfortable and can thrive well.

  • light and permeable
  • clayey
  • alternatively containing sand
  • high in nutrients
  • freshly moist to well wet but without water-logging
  • rather calcareous
  • pH-level: neutral to alkaline

Substrate

When you plant a water elder shrub in a tub, you should use a high-quality substrate. Common flower soil clumps a lot, the permeability does not exist anymore and mold can develop on the ground surface. Same applies to turf.

When it comes to the substrate, you should make sure that the pH-level is up to a neutral or alkaline value as well has parts of sand and/or clay. Optimal is also a substrate with additional perlite which improves the permeability of the substrate even further. You can also use a high-quality flower soil and enrich it yourself. Mix it with a part each of sand and clay. Instead of perlite you can mix in clay granules.

Planting

Planting Period

The optimal planting period is in fall and in spring. In fall you should early take care of the planting, so that the snowball tree species has enough time to get settled in before the first frost.

Planting in the Flower Patch

When you have found the optimal location for your snowball tree, there is nothing holding you back from planting.

This is how to proceed:

  • dig a planting hole which is at least double as wide and deep as the plant bale
  • on top of the planting soil, place a drainage from quartz sand or gravel
  • spread out a layer of soil on top
  • place the plant inside and fill up with soil
  • when appropriate, enrich the soil with sand or clay before
  • a bit of compost will deliver more nutrients
  • press on the plant bale well in the bottom soil for more stability
  • the soil on the sides will only be pressed on lightly for it to remain loose and permeable
  • water moderately
  • planting distance: at least a meter

The Viburnum opulus is mostly prone to a plant lice pest infestation during winter. The same kind enjoys to attack Jasmine and therefore both plants should not be placed in close proximity to each other.

Planting in the Tub

When planting in a tub, you should go about it in a similar way as under “Planting in the Flower Patch” described. You should only remember to use a high-quality substrate and especially to not forget a drainage at the tub bottom.

Plant the snowball tree so deep that between soil surface and tub rim are at least two centimeters of space. In this way, you will prevent that a possible sludge formation after watering will overflow. Use a tub size which is at least twice the size of the plant bale. Because the snowball tree can quickly gain circumference and weight, the tub is otherwise prone to fall over at any blast of wind.

Re-potting of the snowball tree should happen about every three years or at the latest when the tub becomes too small. This is the case when stability cannot be ensured or when the roots are growing through the drainage hole at the bottom or through the ground surface.

Watering

The watering schedule and the watering amount is decided mainly by the location. Basically, it applies that the sunnier and warmer the location is, the more water is needed by the cramp bark.

You should always check the ground and the tub substrate for the current moisture level. For this, press your thumb hard on the soil surface. The ideal time for watering is when the soil surface is slightly dried but still can be pressed in for about two centimeters. Avoid complete dryness of the soil. Note that tub plants can dry out quicker due to the little amount of soil and therefore need to be watered more often.

During hot summer days, you can water your snowball tree generously with the water hose if you have inserted a drainage at the bottom so that no water-logging occurs. This way you provide for saving capacity in the ground and you do not have water daily.

Guelder-Roses planted in a tub should not be placed on a saucer if you cannot ensure that the excess water can be drained because for example the planting tub is too heavy to lift. During summer, watering should always happen early in the morning or ideally at night when no sun shines on the shrub.

Fertilizing

Only when the snowball tree is placed in nutrient-low ground, it is advisable to add an organic complete fertilizer every six to eight weeks. The first administration of fertilizer should happen beginning of May so the Viburnum opulus will receive an optimal treatment for start of the flowering period.

If the snowball tree is placed in a rather moist ground, it is advisable to fertilize with compost every few weeks because it will provide a slightly sour ground environment. If you want to optimize the growth of blossoms and flowering durations, add a phosphorous fertilizer every two weeks starting in April. Make sure not to use a fertilizer with nitrogen because it affects blossoming negatively. Freshly planted and re-potted plants will not be fertilizer in the first four to six weeks.

Pruning

Because the snowball tree only blooms when the shrubs are at least two years old, you should be careful with a radical pruning treatment. This should only be done if the Viburnum falls apart extremely at the sides. With radical pruning, you can bring the shrub to thick growth again. In this case, blossoming can only be expected after one year without flowerage. You should restrict it to a thinning after the flowering period. For this, shorten the new shoots as well as old wooden handles about max. one third.

Regardless of radical pruning or thinning, a cut should basically occur in spring until May or in fall between September and October. With cutting during fall, it is advisable to close the wounds at the wooden parts with Sulphur powder or wax. This way, the cut can dry quicker and will not have frostbite damage due to an early frost.

Overwintering

The European cranberry bush is hardy and can easily remain outside during the winter months, even during minus temperatures. Only young plants in their first year of life should be protected from frost. Wrap at a protective cover of raffia, brushwood or jute around it. If young plants are supposed to remain in a tub outside during winter, place them on Styrofoam or something similar with isolating characteristics for the ground cold not to reach the roots.

Multiplication

To décor your garden, patio or balcony with a beautiful flowerage, it will pay off to multiply the not quite cheap Viburnum opulus yourself. With the correct instructions, even non-garden-professionals will succeed.

Cuttings

When the snowball tree sprouts strongly during summer, it is the perfect time for multiplication by cuttings.

This is how to proceed:

  • separate a new cutting or at least 10 centimeters from the mother plant
  • break off the lower leaves up to half of the cutting
  • place it in a transparent glass filled with water
  • place it at a bright spot sheltered from wind and without direct sun light
  • ideal temperature: 21 degrees Celsius to 25 degrees Celsius
  • at the latest, exchange the water every two days
  • if roots developed, you can plant the cutting into the soil
  • enrich the soil with special cultivation soil
  • keep the soil moist but avoid water-logging
  • when frost occurs, the young plants need to be placed in a warm spot or protected with a jute bag or a raffia mat
  • from the following spring, you can treat the young plants just like adult Viburnum

Diseases

The snowball tree is not relatively prone to diseases. Only too little or too much moisture can lead to the leaves turning brown. In this case, adjust the water amount to the demand as described above in the section “Watering”.

Pest Infestations

Of discoloration or crippling of the leaves shows and the blossoms do not mature, the snowball tree most likely has plant lice.

A quick relief is a traditional home-remedy that consists of high-concentrated soap solution and a few drops of spirit. Hose off the plant well with the garden hose. This way, you will already get rid of most of the plant lice. Afterwards, spray the shrub equally with the soap solution. Now, even the last plant lice will disappear and you will for now not have to fear another infestation.

There are about up to 200 species including sub-species of the snowball tree, of which it is the most common and known.

Very popular as well is the “roseum”. Its leaves color wine-red to dark-red during fall. The up to eight centimeter big flowers especially stand out from May to June. It is ideal as a bird protecting hedge because it does not grow fruit during fall which might attract birds.

The Viburnum lantana is a summer-green shrub with umbrella-shaped flowers. From August, the blossoms will be exchanged for berries. It is one of the lowest maintenance species and perfect for garden beginners.

Also, there is a wide variety of ornamental plants in the Viburnum genus, among them are:

  • ltrilobum
  • farreri
  • plicatum
  • carlesii
  • tinus
  • burkwoodii
  • rhytidophyllum
  • bodnantense or “Dawn”
  • snow ball tree “Eskimo”

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SERIES 18 | Episode 36

Viburnums are mostly native to Europe, America and North Asia, but they also grow well in Australia’s temperate regions. There are over 150 species and growing one of them will add interest and colour to your garden most of the year. They can be either deciduous or evergreen, but the thing that makes viburnums similar is the way the tiny flowers are clustered together, much like an umbrella. It’s called an inflorescence, or a corymb, and it’s where the pink, white or cream flowers are tightly packed together.

One of the most common viburnums is laurustinus or Viburnum tinus. It’s a really tough, evergreen plant. It originated in the Mediterranean and once established, can stand up to anything. It makes a great hedge, but needs a prune in spring. It has little clusters of tiny pink buds that open out into white flowers. It makes a fine shrub but is mainly grown as a great hedging plant. It grows well either in the sun or dense shade.

Other favourites are:

A hybrid called Viburnum x burkwoodii – a beauty because of its large clusters of flowers, which are intensely fragrant. It has lovely lime green leaves, and is a hardy shrub. It’s grown in older gardens, but should be planted more often because it is so hardy.

Another less well-known viburnum that flowers in winter and early spring is Viburnum fragrans or Viburnum farreri – named after the Chinese explorer. It comes from the north of China and it’s more upright in its growth habit. It has a wonderful delicate cluster of sweetly-fragrant flowers that are followed by a little scarlet berry. It is a very fine plant.

For something really spectacular try Viburnum macrocephalum. “Macro” means large and “cephalum” means head – and the flowers get bigger as the season develops to reach almost basketball size. It’s also called the Chinese snowball tree. The colour changes from lime green to a beautiful creamy white and it’s one of the most spectacular shrubs for a garden.

The Korean viburnum, Viburnum carlesii, is deciduous and in early spring has a wonderful cluster of pink buds and an absolutely beautiful perfume. A little piece in a vase would fill the room with perfume – it’s a magnificent shrub.

Viburnum buddlejifolium is from central China but it’s rarely found in Australian gardens – although it’s growing robustly in Melbourne’s Royal Botanic Gardens. The flower hasn’t much fragrance, but the plant is semi deciduous and the leaves are quite long, are a deep green, deeply-veined on the underside and felty to touch. It’s worth hunting out for your garden.

Viburnums are really tough plants. You might read that they need a lot of moisture, but in my experience and over the last few years of drought, they have done well with little water and mulch over the roots. If you like pruning, then when the flowers are finished at the end of spring, remove them and tidy up the bush. Viburnums also take some pruning, but most often they don’t need much attention. Viburnums are great plants that should be remembered because they’re useful and often fragrant.

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