Mahonia oregon grape holly

Oregon grape-holly

Size & form

A semi-evergreen shrub reaching 4 to 5 feet high with a suckering habit.

Tree & Plant Care

Prefers part-shade to full shade in a protected site.
Leaves of plants in northern climates tend to winter burn. Protect from wind and winter sun.
Best in well drained, acidic, loamy soil. Tolerant of dry sites once established.
Prune regularly to control size, but wait for old leaves to drop and new growth to begin in spring.

Disease, pests, and problems

Not tolerant of alkaline soil, poor drainage, compacted soil, full sun or exposed sites.
Leaf scorch, aphids, scale

Disease, pest, and problem resistance

Deer, rabbit

Native geographic location and habitat

Northwestern U. S. in rocky woods and coniferous forests

Attracts birds, pollinators, or wildlife

A rounded blue-black berry with a whitish cast (bloom) in late summer, looks like clusters of grapes and may persist into early winter

Bark color and texture

Stout, light brown, unbranched stems with small winter buds

Leaf or needle arrangement, size, shape, and texture

Alternate, evergreen to semi-evergreen, glossy, compound pinnate leaves with 5 to 9 leaflets; elliptical to ovate with spiny margins
New growth emerging reddish, changing to lustrous dark green, to a deep burgundy fall and winter color. Winter burn leaves drop off in spring as new growth is emerging.

Flower arrangement, shape, and size

Bright yellow, clusters of erect, 2 to 3 inches long and wide terminal racemes, blooms in April and contrasts with last years burgundy foliage.

Fruit, cone, nut, and seed descriptions

Rounded clusters of blue back berries with a whitish-blue cast (bloom), look like grape clusters and persist into early winter.

Cultivars and related species and their differences

Compact Dwarf Oregon grape-holly (Mahonia aquifolium ‘Compactum’): A dwarf form reaching 2 to 2 1/2 feet high with glossy leaves and bronze winter color.

Creeping Mahonia (Mahonia repens): A species similar to Oregon Grape-holly with a stiff, low growing, creeping plant reaching 10 to 18 inches high.

New Market Oregon grape holly (Mahonia x decumbens): A hybrid of Mahonia aquifolia and Mahonia repens.

Think Twice about Leatherleaf Mahonia

(Editor’s Note: This article was originally published on January 25, 2009. Your comments are welcome but please be aware that authors of previously published articles may not be able to respond to your questions.)

Leatherleaf is not a fabulous, showstopping shrub. Yet this same plant has special talents that keep it out of the “slate for total annihilation” category. Thinking twice about leatherleaf mahonia is a good exercise in assessing a plant’s suitability in your particular landscape situation.

Hardy, adaptable, hollylike broadleaf evergreen

Mahonia bealei (also called leatherleaf mahonia or Beale’s barberry) is originally from China but has been available to Western gardeners for generations. It’s a medium sized bush that reminds you of holly but with compound leaves borne on upright stems. A coarse textured flowering shrub, it does best in a somewhat shaded location. Mature height for leatherleaf is in the range of 8 to 12 feet. Leatherleaf mahonia is not picky about soil type, rarely suffers from insect pests, and is said to be hardy in zones 6 through 9.

Winter flowering

Winter is when leatherleaf mahonia catches your eye. Notice the new year’s growth as cold weather settles in, when bright-yellowish green buds swell from the tips of the stems as shown above. Each growth point erupts into a cluster of one to two dozen spires of yellow flowers, tiny bright bells above the dark green foliage. If you’re lucky and have a warm spell in midwinter, be sure to step closer and enjoy your first scent of spring. You might even see a brave bee working the flowers on an early nectar gathering mission. Each flower produces a small oval, purple fruit. The strings of purple fruits are reminiscent of grape clusters; some Mahonias have “grape” incorporated in the common name. Birds enjoy those fruits.

Naturalized, not native, in North America

Leatherleaf mahonia was brought to Europe from its home in China in the 1800s. This shrub’s ability to tolerate many sites, and the fact that birds eat the berries, has allowed leatherleaf mahonia to naturalize in parts of the United States. The USDA Natural Resources Conservation Service PLANTS database shows this species populating most of the southeastern states. In fact, some states have listed leatherleaf mahonia as an invasive plant or noxious weed, making it ill advised or illegal to plant leatherleaf in those areas. Invasive.org currently shows this Mahonia on prohibited plant lists in Alabama, Georgia, Michigan, South Carolina, and Tennessee.

In your landscape?

Since this barberry can self sow, you may find yourself gifted with a seedling through natural processes. It’s also available commercially. Should you use leatherleaf mahonia in your landscape? In areas where this plant has not (yet) been found to be invasive, you might want to use this shrub for its unique look. A number of Dave’s Gardeners have given it favorable marks in PlantFiles. Keep these points in mind:

It’s a very stiff prickly bush. That may make it a good choice for a barrier or security planting, as a tough, natural deterrent to passersby or lingerers. Site it carefully. At the least, you’ll want to allow ample distance between your leatherleaf and your sidewalks or deck. It can be maintained easily to a five or six foot width. This bush is NOT to be brushed up against.

It’s a slow narrow grower, tending to few upright stems. This barberry won’t spread widely; left alone, it will have a few stems, each bearing a top hat of large compound leaves. For more branches, and thus most blooms, judiciously prune one or more stems. New growth will emerge just below the cut. Leatherleaf’s slow growth rate makes it very easy to maintain at a desired size.

It can self sow. Although only a few states have listed it as invasive or noxious, one would think there is potential for leatherleaf mahonia to expand its range. A Dave’s Garden user in South Carolina has commented negatively in PlantFiles, attesting to leatherleaf’s persistence in that region. I seriously doubt the Plant Police will raid your yard, but surely we should heed the recommendations of those who study noxious plants as a career and comply with their statutes.

In final analysis, leatherleaf doesn’t seem to be such a bad guy in many places, and can be useful and attractive in its own way. But the world of cultivated and native shrubs is big. Mahonia aquifolium, Oregon grape holly, is a native American relative of leatherleaf.

Why not read Winter Blooming Shrubs: The Short List by Jacqueline Cross for ornamental alternatives to leatherleaf? The Garden In Winter by Larry Rettig suggests many other ideas for winter interest. Or refer to What to Feed Backyard Birds by Marna Towne, so you’ll know how to keep the birds happy in winter without leatherleaf Mahonia. I think that about covers the second (and third and fourth…) thoughts you might have about leatherleaf mahonia. With these linked resources, and more available to you in Dave’s Garden, you should be able to resolve second thoughts on just about anything in your garden.

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Resources and credits

Invasive.org- A helpful website for researching possible invasive plants in North America

USDA NRCS Plants Database- A helpful site for researching plant species in North America

Duke University page about leatherleaf mahonia

Klingaman, Gerald, extension agent retired, University of Arkansas Plant of the Week article, 2004

Virtual Plant Tags- link to a page on leatherleaf mahonia, citing Dirr’s observations

All photos taken by and property of the author.

*If possible, feel free to dmail me and describe what its like to NOT be excited about plants.

MAHONIA

These useful and easy-to-grow plants remind many people of holly (Ilex), though they’re closely related to barberry (Berberis). Handsome, typically spiny leaves are divided into leaflets. Showy yellow flowers are borne in dense, rounded or spikelike clusters in late winter or spring. Blooms are followed by berrylike blue, blue-black, or red fruit that attracts birds. Prune to reduce size or lankiness, cutting selected stems to the ground or to a node. Avoid planting too close to walkways and sitting areas, where prickly foliage might snag passersby. Generally pest free and seldom browsed by deer. Provide well-drained soil.

oregon grape holly

mahonia aquifolium

  • Zones US, MS, LS; USDA 6-8.
  • Native from British Columbia to Northern California.
  • Erect growth to 6 feet or taller; spreads by underground stems to 5 feet wide.
  • Leaves 410 inches long, with five to nine very spiny-toothed, oval, 1- to 212 inches leaflets that are glossy green in some forms, dull green in others.
  • Young growth is ruddy or bronzy; scattered mature red leaves.
  • Purplish or bronzy leaves in winter, especially in Upper South or where plants are grown in full sun.
  • Spring flowers in 2- to 3 inches clusters along stems; edible blue-black fruit with a powdery coating (makes good jelly).

Compactum

  • grows 23 feet tall and wide and spreads freely to make broad colonies.
  • New leaves glossy, light to coppery green; mature leaves matte, medium green.
  • Kings Ransom’ is an upright grower to 56 feet tall and 45 feet wide; dark bluish green leaves turn red-purple in winter.
  • Orange Flame, 2 feet tall and 3 feet wide, has bronzy orange new growth and glossy green mature leaves that turn wine red in winter.

Oregon grape holly can take any exposure, though it does best with some shade in the Lower South and wind protection in the Upper South. Use in masses as foundation planting, in woodland garden, as low screen or garden barrier. Control height and form by pruning; if woody stems jut out, cut them down to ground (new growth fills in quickly). Unlike other mahonias, this one needs acid soil; develops chlorosis (yellow leaves with green veins) in alkaline soil. Regular water.

mahonia eurybracteata ‘Soft Caress

  • Zones MS, LS, CS; USDA 7-9.
  • Grows 3 feet tall and 312 feet wide with soft textured, narrow, bamboo-like foliage.
  • Thornless.
  • Bright yellow flowers in winter, followed by dark blue berries.
  • Great texture for containers, Asian gardens, and as specimen.
  • Best in part to full shade.
  • Regular water.

chinese mahonia

mahonia fortunei

  • Zones LS, CS; USDA 8-9.
  • Native to China.
  • Grows to 6 feet high, 3 feet wide; stems bear 10 inches., matte green leaves with 7 to 13 spiny-toothed leaflets.
  • Undersurface of leaves is yellowish green, with heavily netted veins.
  • Flowers in short clusters in late summer to early fall; purple-black berries seldom develop.
  • Plant has an unusual stiff charm and is grown for form and foliage, not fruit.
  • Full sun to light shade.
  • Moderate water.

mexican barberry

mahonia gracilis

  • Zones MS, LS, CS; USDA 7-9.
  • Native to Mexico.
  • To 3 feet high, 4 feet wide.
  • Glossy leaves have 5 to 13 overlapping leaflets, each about 112 inches long.
  • Foliage is most colorful in full sun: leaves are lime-green when new, darker green in summer, and a lively mix of reds, oranges, yellows, and light green in winter.
  • Bright yellow, very fragrant blossoms in winter.
  • Blue fruit with a powdery sheen.
  • Tolerates extreme heat and poor soils, even hard-packed clay.
  • Needs little or no supplemental water.

LEATHERLEAF MAHONIA

mahonia japonica Bealei Group(Mahonia bealei)

  • Zones US, MS, LS, CS; USDA 6-9.
  • Native to China.
  • Grows 1012 feet high and 10 feet wide, with strong pattern of vertical stems, horizontal foliage.
  • Leaves over 1 feet long, divided into 7 to 15 broad, leathery leaflets to 5in.
  • long; leaflets grayish or bluish green above, olive-green below, with spiny-toothed edges.
  • Very fragrant flowers in erect, 3- to 6 inches-long, spikelike clusters at branch ends in earliest spring.
  • Blue berries with a powdery sheen.
  • Distinguished plant against stone, brick, wood, glass.
  • Takes sun in Upper and Middle South; best in part shade elsewhere.
  • Plant in rich soil with ample organic material.
  • Regular water.

mahonia oiwakensis lomariifolia(Mahonia lomariifolia.) BURMESE MAHONIA

  • Zones LS, CS; USDA 8-9.
  • Native to China.
  • Showy plant to 612 feet high and 6 feet wide, with erect stems that branch only slightly.
  • Young plants often have a single, vertical, unbranched stem; with age, plants send up more near-vertical branches from near base.
  • Clustered near ends of these branches are horizontally held leaves to 2 feet long.
  • In outline, leaves look like stiff, crinkly, barbed ferns; each has as many as 47 thick, spiny, glossy, green leaflets arranged symmetrically along both sides of central stem.
  • Flowers in winter or earliest spring grow in foot-long, erect clusters at branch tips, just above uppermost cluster of leaves.
  • Blue fruit has a powdery sheen.
  • Prune stems at varying heights to induce branching.
  • Needs shade at least in afternoon to keep deep green color.
  • Regular water.

mahonia xmedia

  • Zones MS, LS, CS; USDA 7-9.
  • Hybrids between Mahonia lomariifolia and Mahonia japonica.
  • Plants bear upright clusters of fragrant flowers in late fall and winter; generally resemble Mahonia oiwakensislomariifolia and require the same conditions.
  • Arthur Menzies grows to 15 feet high and half as wide.
  • Buckland and ‘Charity’ grow to 15 feet high, 12 feet wide; ‘Faith’ reaches 610 feet high and 6 feet wide; ‘Hope’ and ‘Lionel Fortescue’ grow to 6 feet high and wide; ‘Underway’ and ‘Winter Sun’ reach 45 feet high and as wide.

texas mahonia

mahonia swaseyi

  • Zones MS, LS, CS, TS; USDA 7-11.
  • Native to Texas and Mexico.
  • Spiny growth to 35 feet tall, 5 feet wide.
  • Leaves are rosy when young, light green in summer, reddish purple in fall and winter.
  • Fragrant yellow spring flowers; bright red berries.
  • Good barrier plant; can be sheared but looks most attractive when allowed to take its natural shape.
  • Best in full sun; tolerates much heat.
  • Provide well-drained soil.
  • Needs little or no supplemental water.

agarita, texas currant

mahonia trifoliolata (Berberis trifoliolata)

  • Zones MS, LS, CS; USDA 7-9.
  • Native to Arizona, southern New Mexico, Texas.
  • To 8 feet tall, 6 feet wide.
  • Stiff, upright branches hold leathery, blue-green to gray-green leaves to 3 inches long, each consisting of three spiny-tipped leaflets.
  • Fragrant yellow flowers in spring.
  • Red berries ripen in summer; they make good jelly; also favored by wildlife.
  • Needs good drainage and full sun.
  • Tolerates heat and drought, thriving on little or no supplemental water.

Landscape Plants

  • Evergreen shrub, 3-10 ft, (0.9-3 m), upright, often leggy, although some forms low and broad. Leaves alternate, compound pinnate, (7-9 leaflets), 15-30 cm long, extremely stiff and leathery, spine-tipped along margin which is wavy having distinct troughs between spines, lustrous dark green above, may turn bronze to bright red-purple in winter, especially the latter if in cold areas in full sun. Flowers bright yellow, in 5-7 cm long and wide terminal racemes (early spring). Fruit blue-black berry, bloomy, 8 mm wide (mid-summer).
  • Partial or full shade. Performs best in moist, well-drained, acid soil. Avoid hot, dry soils (such as in parking lots or strips), and desiccating winds.
  • Hardy to USDA Zone 5 Native range from British Columbia to Oregon. State Flower of Oregon.
  • Mahonia: after Bernard McMahon (~1775-1816), an Irish-born nurserman of Philadelphia. Author of The American Gardener’s Calendar (1806 and subsequent years).
  • The genus Mahonia has now been included in the genus Berberis, hence the accepted name for Oregon Grape is Berberis aquifolium. However, in commercial horticulture these plants are still known as Mahonia.
  • aquifolium: the classical name for holly. The leaflets of Oregon Grape somewhat resemble the leaves of English Holly, Ilex aquifolium.
  • Oregon State Univ. campus: north of Cordley Hall; east and west sides of Owen Hall

Grape Holly Plant Care – How And Where To Plant Oregon Grape Hollies And Creeping Mahonia

Growing a grape holly plant in the landscape will offer unique interest to the area. Not only easy to grow and care for, these lovely plants also offer an abundance of food to wildlife through their fall berries. These plants will also add year-round interest through their attractive foliage color and texture.

Grape Holly Plant Info

Oregon grape holly (Mahonia aquifolium) is a handsome, 3- to 6-foot ornamental shrub that can play a number of roles in the garden. The shrub’s appearance changes with the seasons. In spring the branches bear long, hanging clusters of lightly fragrant, yellow flowers which give way to dark blue berries in summer. New spring foliage is bronze in color, turning green as it matures. In fall the leaves take on a pleasing purplish cast.

Another grape holly plant, creeping Mahonia (M. repens) makes an excellent ground cover. With foliage, flowers and berries similar

to the Oregon grape holly shrub, creeping grape holly has all the features of the taller form in a plant that grows only 9 to 15 inches tall. The plants spread by means of underground rhizomes, and seedlings often emerge under the plant where berries fall to the ground.

Although the berries are too sour to suit human taste buds, they are safe to eat and can be used in jellies and jams. Birds love them, and disburse the seeds as they feed.

Where to Plant Oregon Grape Hollies

Plant grape hollies in a partially shaded area with moist, neutral to slightly acidic, well-draining soil. M. aquifolium makes an excellent specimen or foundation plant and also looks good in shrub groupings or borders. When closely planted, the prickly, holly-like foliage forms a barrier that few animals will try to penetrate.

M. repens likes full sun in cool climates and afternoon shade where summers are hot. Plant creeping Mahonia as a ground cover in a variety of situations. It serves to stabilize soil on slopes and hillsides, and it is deer resistant, making it a good choice for woodland areas.

Caring for Grape Holly Plant

Both Oregon grape holly and creeping Mahonia is easy to care for. The plants are drought tolerant and only need watering during extended dry spells. A layer of organic mulch around the plants will help the soil retain moisture and reduce competition from weeds.

Prune the plants and remove suckers and seedlings as necessary to restrict them to the desired areas. Mahonias don’t require regular fertilization, but they may benefit from a layer of compost over the root zone in spring.

Tall Oregon Grape The Barberry Family–Berberidaceae

Mahonia aquifolium (Pursh) Nutt.

(Ma-HOE-nee-uh ak-wih-FOAL-ee-um)

Names: Oregon Grapes have leaflets with sharp spines along their margin. Because of this feature they are often confused with holly. In fact, the species gets its name from the name for English Holly, Ilex aquifolium. Aquifolium literally means leaves that have curved hooks like an eagle’s beak (aquiline is similarly derived). Other common names include Oregon Grape-Holly, Holly-leaved Barberry, Holly-leaved Oregon Grape, Oregon Hollygrape and Mountain Grape. It is the state flower of Oregon.

This species is referred to as Tall Oregon Grape only to distinguish it from Low Oregon Grape, Mahonia nervosa. Mahonia aquifolium is also known as Berberis aquifolium. Some botanists argue that the genus Mahonia is not different enough from the genus Berberis to warrant its own genus. Mahonia is named after American Horticulturist, Bernard McMahon. Horticulturists have consistently continued to use the genus Mahonia to refer to those species with compound leaves that give them a very different appearance from barberries.

Relationships: There are about seventy species of Mahonia in Asia, and Central and North America, about 13 in North America. Some cultivated varieties have been developed. Low Oregon Grape, Mahonia nervosa, is another common Oregon Grape in our region. Creeping Oregon Grape, Mahonia repens, is chiefly an east of the Cascades species. Mahonias easily hybridize; intermediate forms often appear.

Distribution of Tall Oregon Grape from USDA Plants Database

Distribution: Tall Oregon Grape is native along the Pacific Coast from southern British Columbia to Northern California. Its range stretches across eastern Washington to the Idaho panhandle and Western Montana. It also has been found growing in the Eastern United States, mostly in the Great Lakes Region. Having long been valued as an ornamental shrub, it may have been introduced to some of those other areas.

Growth: Tall Oregon Grape grows to about 6-8 feet (2-2.5m) tall and spreads by underground stems to about 5 feet (1.5m) wide. It may grow slowly at first as it becomes established, then will quickly grow to its mature size.

Habitat: Tall Oregon Grape is usually found on somewhat dry, rocky, open sites. It is often found along roadsides; in fact it is a preferred native for new plantings along major highways.

Tall Oregon Grape has 5-9 shiny leaflets per leaf.

Diagnostic Characters: All Mahonias have compound leaves. Tall Oregon Grape has 5-9 leaflets per leaf with one central vein per leaflet. The leaves are generally shinier that those of Low or Creeping Oregon Grape. New growth in the spring is usually a bronzy red. Cold weather in the winter often causes leaves to turn purplish or bronze. Yellow flowers are borne in erect terminal clusters. Dark blue, grape-like berries are about 1 cm across with a silvery bloom.


In the Landscape: Tall Oregon Grape has long been recognized as an outstanding landscaping choice. It can be used as an accent plant or as a screen. Its bronzy foliage, bright yellow, lightly scented flowers and bold texture can make an attractive addition to any landscape, but because of its prickly nature it should not be planted along walkways, where people may inadvertently brush up against it. Old or disfigured stems can be pruned all the way to the ground.

Phenology: Bloom Period: April-May. Fruits ripen September-October.

Propagation: Seeds should be stratified for 90 days at 40º*F. (4ºC) or planted outside as soon as they are ripe– seeds should not be allowed to dry out. Cuttings should be taken in late fall and treated with hormone. Suckers from large plants may also be replanted.

Oregon Grape berries make great jelly!

Use by people: Some natives ate the sour berries fresh. The juice has a lot of natural pectin and is great made into jelly or wine, by itself or in combination with other berries such as Salal. The roots of all Mahonias are bright yellow and were often used for making dye, especially for baskets.

Use by wildlife: Birds eat the berries of Oregon Grape. The foliage provides cover for many species and browse for deer. The flowers are very attractive to insect pollinators and hummingbirds.

Links:

USDA Plants Database

Consortium of Pacific Northwest Herbaria

WTU Herbarium Image Collection, Plants of Washington, Burke Museum

E-Flora BC, Electronic Atlas of the Flora of British Columbia

Jepson Eflora, University of California

Calphotos

Ladybird Johnson Wildflower Center

Virginia Tech ID Fact Sheet

Native Plants Network, Propagation Protocol Database

Plants for a Future Database

Native American Ethnobotany, University of Michigan, Dearborn

*Creeping Oregon Grape

Mahonia repens (Lindl.) G. Don

Creeping Oregon Grape or Creeping Mahonia is another valuable landscape shrub/groundcover. Some consider it a variety of Tall Oregon Grape. It does hybridize easily and intermediate forms can be found. It is native to much of the western United States, but grows mostly east of the Cascades from Central BC southward, only reaching the coast in southern Oregon and northern California. It is a good as a groundcover that grows only 1 to 2 ft. (30-60cm) tall, spreading by underground rhizomes; in full sun or partial shade.

Links:

USDA Plants Database

Consortium of Pacific Northwest Herbaria

WTU Herbarium Image Collection, Plants of Washington, Burke Museum

E-Flora BC, Electronic Atlas of the Flora of British Columbia

Jepson Eflora, University of California

Calphotos

Ladybird Johnson Wildflower Center

USDA Forest Service-Fire Effects Information System

Virginia Tech ID Fact Sheet

Native Plants Network, Propagation Protocol Database

Plants for a Future Database

Native American Ethnobotany, University of Michigan, Dearborn

Plant of the Week: Oregon Grape Holly

The University of Arkansas System Division of Agriculture does not promote, support or recommend plants featured in “Plant of the Week.” Please consult your local Extension office for plants suitable for your region.

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Oregon Grape Holly
Latin: Mahonia aquifolium

Oregon Grape Holly is probably the best garden plant Lewis and Clark brought back to the United States when they made their trip into the newly acquired Louisiana Territory.

Most of us have a finite amount of space in our gardens, so the decision to add a plant into the mix is a serious one. Though easily distracted by glitz and glamour, I try to make a point to use plants that have a story to tell.

The Oregon grape holly ( Mahonia aquifolium) is on my short list to add to my garden because of the Lewis and Clark expedition of 200 years ago.

Oregon grape holly is an evergreen shrub growing 5 to 6 feet tall from branches produced by a slowly spreading underground root system. It’s neither a grape nor a holly but a member of the barberry family. It has compound leaves with 11 to 19 leaflets, each about 2 inches long and ringed with spiny teeth. In the summertime, leaves are dark green; in winter they turn maroon.

In later winter, clusters of small, bright yellow blossoms open along slender peduncles borne at the ends of the branches that radiate outward like spokes on a wheel. In June, raisin-sized berries ripen to crown the branches with rows of waxy, bluish fruit.

Oregon grape holly is native from the British Columbia to northern California . The intrepid explorers and their band picked seeds and herbarium specimens along the Columbia River as they headed towards the Pacific. Of the 178 new plants Lewis collected, Oregon grape holly is perhaps the best general garden shrub for eastern gardens.

Our national fascination with Lewis and Clark is understandable, for theirs is a timeless tale for anyone interested in natural history, geography, anthropology, leadership or plain old adventure. Neither Lewis nor Clark were well versed in plants, so President Jefferson sent Merewether Lewis to Philadelphia for a crash course in botany from Dr. Benjamin Smith Barton. While there, Barton introduced him to Bernard M’Mahon (1775-1816), a Philadelphia nurseryman and friend of the president.

M’Mahon had considerable experience in growing woody plants from seed. Though trained in gardening in his native Ireland , he became the first American-based author to produce a book on the subject for gardeners in the new nation. The American Gardener’s Calendar was published in 1806 and is still easy to find in print from its many editions.

Around the table in M’Mahon’s kitchen, he and Lewis discussed how to collect and safely store seeds. When the expedition returned to the United States , the seeds were turned over to M’Mahon who succeeded in getting many to germinate, including the Oregon grape holly. He was the first to offer plants of Oregon grape holly to the public through the pages of his catalog.

Oregon grape holly is an easy to grow plant that is hardy in all parts of Arkansas and as far north as Chicago . To some it’s considered leggy and open; I prefer to think of it as interesting and picturesque. Because of its tendency to produce a topknot of leaves at the ends of bare branches, occasional limb removal back to the ground keeps new branches coming from below and keeps the bush full.

It does best in light shade, but will tolerate full sun if kept well watered. It seems completely immune to insect and disease problems.

By: Gerald Klingaman, retired
Extension Horticulturist – Ornamentals
Extension News – April 15, 2005

The University of Arkansas Division of Agriculture does not maintain lists of retail outlets where these plants can be purchased. Please check your local nursery or other retail outlets to ask about the availability of these plants for your growing area.

When you think about the intelligent, courageous and, inevitably, flawed people who founded our country, a host of names come to mind. Bernard McMahon’s is not among them. However, McMahon—1775-1816—knew or corresponded with many of the political and horticultural notables of his era. He was a garden mentor to Thomas Jefferson, who may be considered America’s “founding gardener.” That association also led the third president to choose McMahon as curator of the plants collected by Lewis and Clark on their lengthy and daring western expedition.

McMahon, an Irish immigrant, was a nurseryman, plant collector and writer. His American Gardener’s Calendar was the first book of guidance aimed at gardeners in our newborn country. He sent American native seeds and specimens to correspondents in Europe and offered European horticultural delights to customers in America. And though early American gardening was necessarily derivative of European gardening, McMahon encouraged his readers to look close to home for worthy plants. Peter Hatch, writing in the January 1993 edition of Twinleaf, the journal of the Jefferson Center for Historic Plants, noted, “It was in the Calendar that American gardeners were first urged to comb the local woodlands and fields for ‘the various beautiful ornaments with which nature has so profusely decorated them’.”

It is no wonder, then, that botanist Thomas Nuttall, McMahon’s contemporary, named a new genus, Mahonia, after Bernard McMahon.

I wish more people would grow Mahonia and not just because McMahon should be honored and celebrated in his adopted country.

Every garden needs structure and evergreen shrubs are a great way of marking boundaries, defining specific areas and providing year-round color. The most common varieties of evergreen Mahonia, sometimes called “Oregon grape holly” do all of that and more. The “Oregon” common name usually refers to an American native species, Mahonia aquifolium, which is native to the West. Sometimes it is also used to describe Mahonia japonica, a native of China, with similar good looks and habits.

If you saw a single Mahonia aquifolium or japonica leaflet—dark, glossy green, with spiny edges—you would think it was a holly leaf. The resemblance does not go much further, as Mahonias and hollies are not closely related. Both genera bear leaves that are alternate on the stems. Mahonia differs from holly in that each “leaf” is really a compound structure up to one foot long, made up of anywhere from seven to 19 leaflets that are also opposed on the stems. Botanists refer to this form is called “pinnately compound”.

True holly leaves start out green and stay that way. Mahonia leaves emerge red and green up as they mature. Holly’s wood is light brown when cut, whereas Mahonia wood is bright yellow, like its relatives, the barberries.

Another very visible difference between true hollies and Oregon grape holly is the flowers. Holly flowers are most often small and white, giving way eventually to the bright red berries that adorn our holiday decorations. Mahonias bear showy panicles or flowerheads of small yellow blooms with a pronounced lily-of-the-valley scent. The bees love them in spring and so do humans.

Once the flowers have faded, the blue “grapes” of Mahonia’s common name appear. These are round to oval, blueberry-size fruits with a waxy or glaucous surface. Though sour, they are edible and can be made into jam if you are so inclined and can get to the bushes ahead of the birds.

Shade gardeners frequently despair about their landscape choices. They can rejoice in Mahonia, which thrives in partial shade. Once established in neutral to acid soil, it can also survive drought. Many true hollies grow into substantial trees; aquifolium and japonica grape hollies top out at three to seven feet. For those with smaller spaces, the ‘Compacta’ variety of Mahonia aquifolium reaches only three feet tall.

Mahonias suit woodland-type gardens, evergreen showcases and habitat landscapes. The aquifolium species is perfect for native plant gardens. I would choose Mahonia over barberry every time for boundary hedges. Like barberry, Mahonia increase by producing root suckers, but if you watch out for them and remove them promptly, the plant will not spread. If any pruning is necessary, do it after the flowers have faded.

Throughout America’s history, people have applied their own definitions to the word “patriotism” and those definitions sometimes cause conflict. If you want to define non-controversial patriotism—and good horticultural judgment–in your own garden, plant Mahonia aquifolium and honor Bernard McMahon.

Colorado State University

Creeping grape holly is probably one of the most useful plants available to regional gardeners. It will thrive in any number of situations. This native plant grows abundantly in the foothills and upper mountains. Related species have been a part of our regional landscape for millions of years and can be categorized as “living fossils.” Several species have been discovered as fossils in the Oligocene beds of Creede and Florissant.

In our modern landscape, creeping grape holly stands out as one of a handful of native plants classified as broadleaf evergreens. Here is a plant for all seasons, with foliage that lasts month to month. This holly is the perfect addition to the garden, especially when you need a sturdy, reliable plant that doesn’t require extensive maintenance.

Creeping grape holly is a low-growing shrubby plant. It grows six to 12 inches high, but height is easily controlled by pruning, which will also encourage the plant to become fuller in width. The cut stems are very useful in winter holiday wreaths and arrangements. Fresh foliage appears in the spring, followed by yellow flowers that ultimately yield blue berries that are often used to make a flavorful jelly.

Grow this plant in sun or shade; it really isn’t too fussy. Once established, the creeping grape holly requires very little water. An occasional shearing will keep it in bounds.

For more information, see the following Colorado State University Extension fact sheet(s).

  • Fall and Winter Watering
  • Xeriscaping: Ground Cover Plants
  • Ground Cover Plants
  • Trees and Shrubs for Mountain Areas

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Master Gardener: A native in the garden — Oregon grape

This spring, everywhere I look — on the trail and in my yard — I see pretty clusters of small, bright yellow flowers above holly-shaped spiny leaves. The leaves are mostly rich green and may have spots of orange and red. These small woody shrubs are Oregon grape, named for their edible but tart grape-like berries that appear later in the summer.

The tall form of Oregon grape (Mahonia aquifolium or Berberis aquifolium) is the state flower of Oregon and grows to be 3 to 6 feet. The plant I am seeing is much smaller — 1 to 2 feet — and is creeping Oregon grape (Mahonia repens or Berberis repens).

This broadleaf evergreen plant has many names — Oregon grape, Oregon grapeholly, Holly-grape and Mountain holly — which is confusing because it is neither a grape nor a holly. Creeping Oregon grape may also be called creeping mahonia, creeping barberry or prostrate barberry.

Even the Latin names are confusing. The plant is sometimes listed with the genus Mahonia and sometimes with the genus Berberis. Further, botanists are not in agreement whether the creeping form is a subspecies of the taller form or a species of its own, resulting in yet more Latin names for the smaller form (Mahonia aquifolium var. repens or Berberis aquifolium var. repens).

Once you know the various names, you can find a wealth of information about Oregon grape. Both forms are native to the western United States, and the creeping form is native to our area. It may be found in complete shade, partial shade and open areas. This time of year, you can see the bright yellow flowers along popular hiking trails in this area as well as on the Front Range.

The creeping Oregon grape in my yard is growing unattended under and around the edges of conifers, chokecherries and serviceberries, sheltered from winter sun and drying winds. It is growing in a sprawling fashion in some areas and is tall and leggy in other places. Some flowers perch on stems more than 2 feet tall.

It is a wonderful plant for those of us who garden for wildlife: the early blooming flowers provide nectar and pollen for bees and butterflies, and summer berries provide food for the birds.

Creeping Oregon grape is a great plant to actively cultivate in our gardens as well. It tolerates sun, likes the shade, requires very little water once it is established and is rarely browsed by deer.

Pruning will result in shorter, denser plants that make for great ground cover in shady areas. It also can stabilize hillsides with its underground growth habit and is resistant to wildfire. Medicinal and edible uses are detailed in “Edible & Medicinal Plants of the Southern Rockies” by Mary O’Brien and Karen Vail.

With its striking yellow flowers set against shiny leaves in reds and greens in spring, followed by pretty blue berries in summer and ending with leaves in all shades of red in the fall, Oregon grape adds interest and value to our yards all season long.

For more information, check out the following.
• Planttalk Colorado – No. 737 – Creeping Grape Holly
• Native Shrubs for Colorado Landscapes – CSU Extension Fact Sheet No. 7.422
• Evergreen Shrubs – CSU Extension Fact Sheet No. 7.414

Vicky Barney gardens for wildlife and is a member of the Master Gardener Class of 2011.

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