Mahonia: Planting, Pruning and Care

Botany

The Mahonias are shrubs comprising nearly 70 species native to Asia and North America. The Mahonia aquifolium originates from North America, mainly Oregon, California and western Canada. It is sometimes called “Oregon Grape” (its berries can be used to make wine). Many species come from Asia, such as Mahonia bealei, Mahonia japonica or Mahonia eurybracteata. These Asian species are generally slightly less hardy than others. Mahonias grow naturally in woodland undergrowth or forest edges, and sometimes on rocky ground, which explains why they prefer shady positions.

The mahonia was named in honour of the American botanist and horticulturist Bernard Mc Mahon (1775–1816), founder of the Philadelphia Botanical Garden. It was introduced to Europe in the early 19th century.

The mahonia belongs to the Berberidaceae family, the family of Berberis, Epimedium and Sacred Bamboo (Nandina). It is particularly close to Berberis (or Barberry), with which it can hybridise to produce shrubs called (x) Mahoberberis, decorative for their evergreen, glossy, spiny leaves that turn beautiful colours in autumn.

The mahonia is an upright shrub that grows slowly. The Mahonia aquifolium reaches only 1 to 1.5 metres in height, while the Mahonia x media can grow up to 5 metres. Most varieties reach a maximum height of 3 metres. There are much shorter mahonias, such as Mahonia pumila and Mahonia repens, which do not exceed 30 centimetres in height. The mahonia has attractive wrinkled brown bark with grey veins. Over time, the base of the shrub tends to become bare.

Mahonia aquifolium: botanical illustration

Depending on the variety, mahonias flower between autumn and early spring. Thus, the Mahonia ‘Soft Caress’ blooms very early in autumn, sometimes as early as August. As for the Oregon Grape (Mahonia aquifolium), it flowers much later, in early spring, around March. The Mahonia x media ‘Charity’ is a variety that brightens gardens in midwinter with its elegant yellow clusters. You can combine different varieties to enjoy their flowers over a longer period.

The flowers are grouped in terminal clusters, sometimes very elongated and slender. They can measure up to 50 centimetres in length. In some varieties, they are much more compact: for example, the Mahonia aquifolium has clusters that measure a maximum of 8 centimetres long. The flowers open gradually from the bottom upwards.

The flowers are generally less than 2 centimetres in diameter. They are cup-shaped and a bright yellow colour, more rarely orange, as in the Mahonia ‘Cabaret’. They are rounded and resemble those of the Berberis. They consist of six to nine petaloid sepals, six petals and six stamens. They are appreciated because they bring much brightness in midwinter.

Mahonia flowers are nectar-rich. They provide bees with nectar at a time when flowers are scarce. They release a pleasant lily-of-the-valley fragrance. Don’t hesitate to use them for bouquets or indoor decorations.

The leaves of the mahonia are thick (leathery), evergreen and pinnate. They are very large and divided into spiny, glossy leaflets. They are dark green, sometimes bluish or silvery, but turn red, purple or bronze in autumn. Young leaves are also reddish in colour. The Mahonia x wagneri ‘Moseri’ is truly impressive for the colours it takes on through the seasons: its leaves are green-yellow when young, then turn coppery green, finishing red in autumn!

Mahonias generally have long, large compound leaves. In Mahonia lomariifolia, they can reach up to 60 centimetres in length! In some varieties, they barely exceed 10 centimetres in length. Proportionally to their size, the leaves are composed of a more or less significant number of leaflets. Those of Mahonia aquifolium have only five to nine leaflets, while Mahonia x media has about twenty… But the record seems to be held by Mahonia lomariifolia, which has up to forty leaflets per leaf! They are then much finer, giving the whole leaf the appearance of a fern frond! The leaflets usually have spiny teeth… This is why those of Mahonia aquifolium so closely resemble holly leaves.

Mahonia foliage takes varied forms: from left to right, Mahonia ‘Soft Caress’, Mahonia aquifolium (photo Krzysztof Golik) and Mahonia fremontii (photo Genet)

While the foliage can sometimes look rather coarse and broad, as in the Mahonia aquifolium, mahonias can also impress with their extremely fine leaves, as in the superb Mahonia ‘Soft Caress’. They then become much lighter and more delicate, airy, bringing an exotic touch to the garden. When very fine, they resemble fern fronds. Indeed, the name Mahonia lomariifolia means “mahonia with Lomaria leaves”, Lomaria being a fern. They can also remind us of the leaves of sacred bamboo, Nandina domestica. As its name suggests, the Mahonia ‘Soft Caress’ has very soft, spineless foliage, unlike Mahonia aquifolium, whose leaflets are leathery and spiny. Discover Mahonia ‘Soft Caress’ in our video:

The Mahonia aquifolium produces suckers, allowing it to spread. It can be propagated by lifting and transplanting these suckers.

After flowering, in summer or autumn, the mahonia produces decorative, rounded berries. They are dark blue, almost black. They are not edible raw but can be used to make jam, wine and liqueur. They are eaten by birds.

Mahonia berries (photo Clanmother)

The main varieties of Mahonia

Most Popular

Our Favourite Varieties

Mahonia x media Charity

Particularly elegant, this mahonia bears large leaves composed of about twenty leaflets. Its yellow flowers are gathered in long, upright clusters. They release a pleasant lily-of-the-valley fragrance.

• Height at maturity 3,50 m

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Mahonia aquifolium

Native to North America, the Oregon grape has tough, spiny leaflets. In early spring, it bears fairly short, compact clusters of yellow flowers.

• Flowering time March, April
• Height at maturity 1 m

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Mahonia confusa Nara Hiri - Hybrid Mahonia

This mahonia has silvery foliage, divided into numerous rather fine leaflets, giving it an exotic appearance. In autumn, it produces elongated clusters of yellow flowers. Its foliage resembles that of ferns or sacred bamboo. It is not spiny.

• Height at maturity 1,20 m

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Mahonia japonica Hivernant

The 'Winter Sun' mahonia has dark green, spiny foliage marked with yellow veins. In midwinter, it bears clusters of fragrant yellow flowers.

• Height at maturity 1,50 m

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Mahonia nitens Cabaret

An original mahonia with orange flowers, much earlier than other varieties as they appear in autumn, sometimes as early as August. Its leaves are divided into spiny leaflets and turn purple in winter. It has a fairly compact habit and adapts well to container growing or small gardens.

• Flowering time September to November
• Height at maturity 1,50 m

See the product sheet

Planting

Where to Plant?

Plant your mahonia preferably in shade or partial shade. However, it can tolerate sun, especially if you live in northern France. Conversely, in the south, avoid full sun and opt for partial shade instead. Mahonia thrives under deciduous trees.

Plant it preferably in neutral or slightly acidic soil, although some species, such as Mahonia aquifolium, tolerate limestone fairly well.

It is important to plant mahonia in well-draining, porous soil, preferably sandy. Avoid heavy, compacted, or clay soils, as they may suffocate the roots and retain too much water—mahonias dislike excessive moisture. They do, however, appreciate fertile soils rich in humus. We recommend adding some compost at planting time.

Choose a location sheltered from cold winds and frost, especially for varieties with very large leaves, such as Mahonia ‘Soft Caress’, which are the most cold-sensitive.

Due to its spiny foliage, we advise against planting it near walkways… unless you opt for Mahonia ‘Soft Caress’, whose delicate foliage is thorn-free! This variety is particularly well-suited to container planting, making it ideal for patios.

Choose their location carefully, as once established, mahonias dislike being moved.

When to Plant?

Although they can be planted year-round, the ideal time is between October and March or April. Avoid planting during frost or when the plant is in full bloom.

How to Plant?

For the best effect, we suggest grouping three to five mahonias rather than planting them individually.

1. Moisten the root ball to encourage establishment.
2. Dig a planting hole, two to three times the size of the root ball. Add some well-rotted compost.
3. Place the plant in the hole.
4. Backfill with soil and firm gently.
5. Water thoroughly.
6. Apply a layer of mulch around the base to suppress weeds, protect from cold, and retain soil moisture.

Maintenance

Mahonias are shrubs that require relatively little maintenance. Once mature, they can do without watering, though it’s preferable to water regularly during the first year and subsequently during dry spells. Similarly, if you’re growing your mahonia in a pot or container, water occasionally as the growing medium dries out faster than in open ground.

Applying a mulch around the base will help suppress weeds and protect the shrub from frost. You can also add some well-rotted compost in early spring. Mahonias with larger leaves (such as Mahonia ‘Soft Caress’) are the most cold-sensitive. If growing these varieties, protect them during the first few years with horticultural fleece and a thick layer of mulch on the ground. Once mature, mahonias become quite frost-hardy. It’s also advisable to stake young mahonias for the first few years, as the weight of their leaf clusters and flowers may cause the still-flexible branches to bend. Similarly, if snow accumulates, gently shake the shrub to remove it and prevent branches from breaking under the weight.

We recommend pruning mahonias after flowering, especially in their early years – once mature, this becomes less necessary. Carry out light pruning in late winter or early spring, around April. Remove damaged, broken or poorly positioned branches, and trim back terminal leaf clusters. This will encourage bushier growth.

You can enhance their silhouette by removing leaves and branches growing directly from the trunk, leaving only foliage and flowers at the top of the main stems. This gives the mahonia a more graphic, airy appearance and reveals its often-overlooked bark.

→ Learn more about pruning Mahonia: when and how in our advice guide!

Young mahonias therefore require the most care. Once established, they generally need no pruning or watering, no longer require staking, and become quite resilient to frost and drought.

Mahonias are susceptible to rust and powdery mildew. These fungal diseases thrive in warm, humid conditions and poorly ventilated locations. Rust appears as small orange spots on leaves, while powdery mildew forms a white felting on foliage. Remove and burn affected parts to prevent spread. You can spray with nettle manure, horsetail decoction, or sulphur. We recommend reducing watering and pruning to improve air circulation. Mahonias may occasionally suffer from downy mildew. Few insects or pests attack mahonias, though they may sometimes host aphids or holly leaf miners (caterpillars that tunnel through leaves).

→ Learn more about mahonia diseases and pests in our advice guide!

Propagation

You can propagate mahonia by seed or by cuttings. Taking cuttings seems to us the best technique, as it is simple and will produce young plants more quickly, with the assurance that they will be identical to the original variety. It is also possible to take suckers from Mahonia aquifolium, just after flowering, and transplant them.

Taking Cuttings

Mahonia can be propagated from semi-ripe cuttings between August and October.

1. Prepare a pot by filling it with compost mixed with sand, then moisten the substrate.
2. Take a cutting about 10 cm long from this year’s growth. It should be healthy and disease-free.
3. Remove the leaves near the base of the cutting and trim the others to reduce the leaf surface. Leave only a few leaflets at the top.
4. You can dip the base of the stem in rooting hormone.
5. Make a hole in the substrate using a pencil or a wooden stick.
6. Place the cutting in the hole and gently firm the soil around it to remove air pockets and ensure good contact between the compost and the cutting.
7. We recommend covering the pot with a plastic bag to maintain a humid atmosphere. Ventilate occasionally to prevent fungal diseases.
8. Place the pot in a warm, bright spot but out of direct sunlight.

Sowing Seeds

Sow mahonia seeds in spring. They first need to undergo stratification (a period of cold) to break dormancy, especially if they are Mahonia aquifolium. Other varieties can be sown directly without stratification. Mahonia seed germination is irregular.

1. Harvest the berries when fully ripe. Open them to extract the seeds.
2. Stratify them to break dormancy. To do this, place them in a tray filled with equal parts compost and sand, or just sand. Moisten the substrate and mix in the seeds. Seal everything in a plastic bag and place it in a cold environment (between 0 and 5 °C), such as a refrigerator, for two to three months. Sometimes the seeds germinate while still in the cold. In this case, remove them as they sprout and transplant them into pots.
3. Remove the seeds from the refrigerator.
4. Prepare a pot by filling it with seed compost.
5. Sprinkle the seeds on the surface.
6. Cover with a very thin layer of substrate, as they need light to germinate.
7. Water gently.

Continue watering regularly but not excessively, keeping the substrate moist. Repot the young seedlings a few months after germination. After a year, they can be planted in their final position.

Association

Mahonia is the perfect shrub for creating a splendid winter scene. Pair it with the elegant blooms of oriental hellebores or the delicate flowers of snowdrops. Enjoy the fragrant flowering of wintersweet (Chimonanthus praecox) or the daphne (Daphne odora). To warm up your garden in midwinter, combine it with other yellow blooms, such as those of Eranthis hyemalis, winter jasmine, or witch hazels. You can add touches of orange or red for extra vibrancy.

Pair mahonia with other winter-flowering plants! Mahonia x media ‘Charity’, Hamamelis ‘Jelena’ (photo Meneerke bloem), Chimonanthus praecox (photo Kristine Paulus) and Eranthis hyemalis

Create a shrub border by combining mahonia with other plants that shine in winter, whether through their blooms (daphne, winter jasmine…), their stems (Cornus, Prunus…), their berries (snowberry, Callicarpa…), or their evergreen foliage (Sarcococca, Viburnum tinus…). Since mahonias flower at different times, you can mix several varieties for continuous blooms from autumn to early spring!

Place it at the back of a border. It will make a beautiful backdrop, allowing you to plant lower-growing species in front: winter-flowering perennials or plants with decorative foliage (hostas, heucheras, ferns…). Don’t hesitate to pair Mahonia aquifolium, which blooms in early spring, with spring or late-winter bulbs: daffodils, tulips, squills, bluebells, crocuses, grape hyacinths… As mahonia thrives in shade, you can create a woodland garden by planting it alongside hostas, ferns, and hellebores.

With its striking, deeply cut foliage and slender clusters of yellow flowers, mahonia has a highly graphic quality. It will fit effortlessly into an exotic-style garden, alongside other plants with large, divided leaves for a lush effect. Choose mahonia ‘Soft Caress’ for elegance and pair it with ferns (especially evergreen varieties), Fatsia japonica, or sacred bamboo (Nandina domestica). You could also combine mahonia ‘Cabaret’, which flowers from August, with castor bean (Ricinus communis). Their warm red-orange-purple tones will create a vibrant, tropical feel. Add cannas and phormiums for extra drama. Play with shapes and foliage by pairing mahonia with other architectural plants: bamboos, ferns, horsetails, sacred bamboo… If you live in the city, you can grow it in a container on a terrace or courtyard, transforming the space into an exotic retreat.

Use mahonia to create an exotic display! Mahonia ‘Soft Caress’, Nandina domestica ‘Gulf Stream’, Dryopteris erythrosora, Fatsia japonica (photo Dbxsoul) and Phormium ‘Pink Panther’

Mahonia is ideal for a mixed wildlife hedge, alongside laurustinus (Viburnum tinus), hornbeam, barberries, hawthorns, spindle, privet… Add shrubs with decorative berries like beautyberries or snowberries. The result will be far livelier and more colourful than traditional laurel or thuja hedges, with minimal maintenance. For a defensive hedge, combine mahonia with other spiny shrubs (barberries, hollies…).

Finally, some particularly elegant varieties deserve a standalone spot, showcasing their foliage and spectacular blooms. Alternatively, group three or five plants of the same variety for a dramatic effect.

→ More inspiration in our guide: Mahonia: 7 Planting Ideas

Did you know?

• Uses

Although not edible when raw, Mahonia berries can be used to make jams, jellies, liqueurs or wine. The roots of Mahonia aquifolium can also be used to produce a yellow dye. The leaves, bark and roots have medicinal properties and were traditionally used to treat dermatological or hepatic conditions (liver ailments). They also have diuretic, anti-inflammatory and digestive properties.

• The Emblem of Oregon

As Mahonia aquifolium is native to Oregon, it has become the symbol of this state on the west coast of the United States. It is also called Oregon grape, as its berries can be used to make wine.