How to Plant, Grow, and Care For Highbush Cranberries
Are you looking for a showy plant that produces edible fruits, attracts pollinators, and helps feed birds? Look no further than the highbush cranberry. This cool-weather-loving shrub is perfect for northern gardens. Learn all about the highbush cranberry and how to grow it in your landscape.
Contents
The highbush cranberry, also known as cranberry viburnum or American cranberrybush, is a bit of a puzzle. It produces sweet-tart, bright red, cranberry-like fruits, yet it’s not related to the true cranberry.
American cranberrybush, Viburnum opulus var. americanum, is a variety of viburnum and is native to northern North America. Adding to the confusion, this deciduous native shrub is easily confused with a weedy species from Europe, known as the European cranberrybush, Viburnum opulus.
North American gardeners will want to stick with the native species or one of its equally showy cultivars. You will then have a hardy and easy-to-grow native shrub with beautiful spring flowers and colorful fall foliage. The white flowers and scarlet red berries provide a feast for pollinators and songbirds, and the berries are edible and tangy, and make excellent fruity preserves!
Are you ready to add some form and color to your woodland garden, rain garden, or bird garden? Let’s dig right into the details and see if the highbush cranberry is a great choice for your landscape!
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Highbush Cranberry Overview
Plant Type
Deciduous shrub
Family
Adoxaceae
Genus
Viburnum
Species
opulus var. americanum
Native Area
Northern North America, Canada
USDA Hardiness Zone
2 – 7
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Sun Exposure
Full sun to partial shade
Soil Type
Moist, rich, well-drained, Acidic (<6.0)
Watering Requirements
Medium
Maintenance
Low
Suggested Uses
Native garden, wildlife garden, understory shrub
Height
8 – 12 feet
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Bloom Season
Spring
Flower Color
White
Attracts
Butterflies, bees, birds
Problems
Aphids, viburnum crown borer, viburnum leaf beetle
Resistant To
Shade, poor soil
Plant Spacing
10 – 12 feet
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Plant Natural History
Despite its name, the highbush cranberry is not related to true cranberries (Species Vaccinium, family Ericaceae). Highbush cranberry is a member of the Moschatel family (Adoxaceae), which consists of about 200 species of herbs, shrubs, and small trees, many with showy flowers and fruits. It was previously grouped in the honeysuckle family (Caprifoliaceae).
The native range of the highbush cranberry includes all of the northern United States and Canada. The range extends as far south as Colorado, Illinois, and West Virginia. It will grow in the cooler mountain regions of more southern states but is not considered native in these areas.
In its natural habitat, highbush cranberry is primarily an understory shrub that inhabits woodland margins and open hardwood forests. It prefers moist soils and is often found along streams and wetland edges. This is an important wildlife plant throughout its range and also offers food and medicinal value for humans.
Do not confuse the native highbush cranberry with a similar species, the European cranberrybush (Viburnum opulus). European cranberrybush has escaped cultivation and naturalized in many northern states and Canada. The European species competes with the native highbush cranberry and other native plants. The fruits of the European cranberry bush are not palatable, nor are they favored by wildlife.
Characteristics
The highbush cranberry is a deciduous shrub with a maximum height of eight to 12 feet. It has a medium growth rate and will mature into a multi-stemmed shrub with a rounded, vase-like form. It has thin bark with a smooth to scaly texture and a light gray to tan color. Smaller stems have a reddish tint.
The leaves somewhat resemble maple leaves, typically with three distinctive pointed lobes. The leaves measure three to six inches long and one to three inches across. They are opposite along the stems and coarsely toothed. Color during the growing season is uniformly medium green. In the autumn, the leaves turn golden yellow, followed by shades of red, burgundy, and purple.
Highbush cranberry blooms in the spring. Its lacy white flowers form in flat-topped clusters. Each mass of flowers consists of two distinctly different flower types. The outer flowers are sterile but very showy. These are larger and pure white with five rounded petals. The inner flowers are fertile and much more abundant. These inner flowers are much smaller, creamy white, and have five recurved petals and prominent yellow-tipped anthers.
Bright red berry-like drupes mature in the fall. These can be harvested and eaten raw or preserved as jellies and jams. They have a sweet-tart flavor and can be used as a substitute for traditional cranberries.
Propagation
Highbush cranberry is most easily propagated by seed, stem cuttings, or division.
Seed
You can buy highbush cranberry seeds or harvest ripe fruits and collect your own seeds. Sow the seeds outdoors in the fall, setting them ¼ to ½ inch deep. Allow them to overwinter; this period of cold stratification will allow them to break dormancy the following spring.
When new seedlings emerge, keep them moist and protected from digging and burrowing animals. After two or three years, the seedlings will be large enough to be transplanted to a permanent location, as needed.
Division
If you have a mature highbush cranberry shrub that has started to send up new shoots from around the root area, you can propagate your plant by division. Dig up a healthy root sprout with a healthy stem and section of roots attached. You may need to use a sharp spade or pruners to help cut through any thicker sections of root.
Once separated from the parent plant, transplant your division immediately and water it well. Refill the area you dug out with fresh soil and water it as well. Keep your newly divided plants well-watered for the next several days to help them recover from transplant shock.
Cuttings
You can propagate viburnums from softwood cuttings in the spring or hardwood cuttings in the fall. Use sharp clippers to collect healthy cuttings six to 10 inches long. Remove the leaves from the lower half of your cuttings and dip the stripped stems in a rooting hormone.
Plant your cuttings in pots filled with fresh potting soil. Keep them in a sheltered location with bright, indirect light, and keep the soil moist. The cuttings should root in six to eight weeks. You’ll know if your cuttings are successful when they develop new leaves and grow taller.
Transplanting
Grab your gardening gloves, the time has come to transplant a potted highbush cranberry or other viburnum species to a permanent location. Cool spring and fall days are excellent times for transplanting. Prepare a hole slightly wider and deeper than the pot in which your plant is currently growing. Add any soil amendments and compost and mix it in with the soil.
Carefully remove your viburnum from its pot and place it in the hole. If the roots are curled around in the pot, gently spread them out into the hole. Make sure the main stem or stems are standing upright and not tilted to the side, then backfill the hole around the roots with fresh soil. Water your plant well immediately after transplanting and for the first several days to help it adjust to its new home.
How to Grow
Highbush cranberry is easy to grow. If you have good growing conditions for these plants, you shouldn’t have any issues, and you will enjoy a pleasing, low-maintenance ornamental and fruiting shrub for your landscape.
Sunlight
These shrubs grow well in full sun to partial shade. In their natural environment, they are understory plants adapted to partially shaded habitats. In warmer parts of their range, especially, they do appreciate protection from intense afternoon sunlight.
Water
Highbush cranberry needs regular soil moisture. If your soil dries out frequently, you’ll need to do some extra watering. These plants are adapted to growing in moist conditions and are not drought-tolerant.
Soil
These shrubs tolerate a wide variety of soil conditions but do best in organically rich, moist soils with good drainage. The soil should be acidic with a pH of 6.0 or less. If your soil is poor quality, consider adding some soil amendments such as organic compost at the time of planting to offer some added nutrition.
Climate and Temperature
Highbush cranberry is hardy in USDA Plant Hardiness Zones 2 through 7. It prefers cooler climates and won’t typically grow well in any of the southern states, except in higher elevation mountainous regions away from heat and humidity. It is best adapted to survive in the north-central and northeastern states.
Fertilizing
Rather than adding synthetic fertilizers, add mulch around your viburnums each year. The mulch will help keep the roots cool and moist and as it breaks down, it will add organic material to the soil. Shredded leaf mulch and organic compost make excellent nutrient-rich mulching materials.
Maintenance
You shouldn’t need to do much maintenance with these plants. Annual pruning will help keep your bushes to a manageable size and shape, however. Highbush cranberries do spread by suckering, but not aggressively. Prune off unwanted root suckers each year. Do your pruning immediately after flowering to give the plants a chance to generate fresh stems during the growing season.
Garden Design
Highbush cranberry has widely varied uses and makes an appealing landscaping plant. If you are looking for something that’s both ornamental and edible, use it in your edible landscape for its showy spring flowers and tart fruits. If you’re not a fan of jams and jellies, then grow it for the wildlife in your pollinator garden or bird garden.
Use highbush cranberry as an understory plant in a lightly shaded woodland garden. It’s a great option for a rain garden or wetter site, especially if you have a constant source of water nearby, such as a pond or small stream. Or use it as part of a shrubby border at the edge of a wooded area or as a hedge with a combination of similarly sized deciduous and evergreen shrubs.
Varieties
Several unique cultivars are available for different uses:
‘Bailey Compact,’ Viburnum opulus var. americanum ‘Bailey Compact’
‘Baily Compact’ is a dwarf cultivar that grows five to six feet tall. This nicely rounded shrub makes a good hedge or shrub border. In the fall, its leaves turn a rich red color.
Dwarf American Cranberrybush, Viburnum opulus var. americanum ‘Compactum’
The cultivar ‘Compactum’ is a smaller variety of the highbush cranberry. It reaches a full height of five to six feet with a rounded form. This cultivar has yellow fall foliage.
‘Hahs,’ Viburnum opulus var. americanum ‘Hahs’
The ‘Hahs’ cultivar grows six to eight feet high and equally as wide. If you are hoping to grow highbush cranberries for good fruit harvests, this cultivar may be of interest. It has been bred to produce high fruiting yields. The red fall foliage is also a notable treat.
‘Wentworth,’ Viburnum opulus var. americanum ‘Wentworth’
‘Wentworth’ is an American cranberrybush cultivar that grows eight to 10 feet tall. Its autumn-bearing bright red fruits glow in the morning sun, and its bronze-red fall foliage is sure to please.
Wildlife Value
Highbush cranberry is an excellent wildlife-friendly plant for your landscape. It blooms in the springtime and offers pollinators an abundant supply of early-season nectar. Any butterflies and bees in the vicinity will come for a visit, and you can tempt them to stay longer by growing a few other early-season nectar plants. It is also a larval host plant for the spring azure butterfly caterpillar.
Wait until fall for the showy red fruits, known as drupes. These drupes are just the right size for fruit-eating birds to pluck from the stems and enjoy a tasty treat. As your highbush cranberry matures into its full size, it creates a safe and shrubby habitat for birds to forage, seek refuge, and build their nests.
Common Problems
Highbush cranberry is typically hardy and trouble-free. You may occasionally run into problems with insect pests, however. Be on the lookout for any potential issues so you can identify the cause and correct problems early.
Aphids – Aphids are ubiquitous garden pests that gather in large numbers to suck plant juices with their tiny piercing mouthparts. These soft-bodied insects appear gray, green, yellow, pink, or white and, while small, are clearly visible.
Aphids weaken plants but don’t generally kill them. They do, however, invite other diseases, such as molds and other fungal diseases. Spray aphid clusters with a jet of water to dislodge them and disturb their colonies. This is often enough to prevent them from causing serious damage.
Viburnum crown borer – The viburnum crown borer is a moth whose larvae bore into the bark of viburnum plants. These larvae feed on the lower trunks of the plants and cause plant weakness and, ultimately, death. Borers are attracted to stressed plants, so the first line of defense is to grow your viburnum in an ideal habitat and keep it healthy. If you suspect a crown borer infestation, beneficial nematodes can be used to combat the borers.
Viburnum leaf beetle – Viburnum leaf beetles that feed exclusively on different species of viburnum. These invasive pests were introduced from Europe and cause severe leaf damage. The adult beetles are golden brown and about ¼ inch long. The large are grub-like and grow up to about ⅓ inch long. They can be seen feasting on the leaves and chewing large holes. Neem oil and insecticidal soap can be effective in killing the larvae but will need to be reapplied as needed. Try to catch infestations early before these pests cause serious damage.
Frequently Asked Questions
Do I need more than one highbush cranberry for my plant to produce fruits?
No. While some fruiting plants require at least two plants to successfully set fruits, viburnums are self-fertile and will produce fruits with a single plant. If you have multiple viburnums, you will of course generate more fruits, simply because you have more bushes producing.
How can I tell the difference between the native highbush cranberry and the invasive European cranberrybush?
Unfortunately, it is very difficult to tell the difference. The flowers, leaves, and berries all look remarkably similar. The European variety has very bitter fruits that are generally considered inedible, while the American native cranberrybush has tart but fully edible fruits.
When not fruiting, you’ll have to look closely at the glands on the leaf stalk. Protruding rounded glands on the stems at the base of the leaves on the American highbush cranberry are rounded, not sunken inwards. The protruding glands on the stems at the base of the leaves on the European variety are flat-topped and sunken in with a little divet. It’s a very subtle difference, but useful to tell these two species apart.
Where can I buy the native highbush cranberry bush?
Various species of viburnum are popular landscaping plants. You might find highbush cranberry or one of its cultivars in the flowering shrubs section of your local garden center. You can also check for nurseries that specialize in native plants or ask your nearest garden club or botanical garden for a list of reputable native plant vendors.