How To Grow And Care For Mahonia

The eye-catching, easy-to-grow mahonia shrubs (Mahonia spp. or Berberis spp.) remind many people of holly (Ilex), though they're closely related to barberry (Berberis). Handsome, spiny leaves are divided into leaflets that change colors with the seasons. In late winter or spring, showy yellow flowers bloom from dense, rounded, or spike-like clusters. Blooms are followed by berrylike blue, blue-black, or red fruit that attracts birds—plant as a single, eye-catching plant or amass multiples in a shrub bed. Plant them when the temperatures are mild, in fall or spring. They are steady growers, but the growth rate depends on the variety. Some varieties are considered invasive.

Here is what you need to know about growing and caring for mahonia in the South.

Plant Attributes

Mahonia Care

Mahonia is a low-maintenance plant with few care requirements. Provide well-drained soil and filtered light during the hottest part of the day. Add rich organic matter to the soil when planting. Once the plant is in the ground, mulch its base. Water regularly the first year to establish growth. Mahonia needs an occasional pruning to reshape or remove woody canes. It is both pest- and deer-resistant. Prune to reduce size or leggy growth, 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. Mahonia is pest-free and seldom browsed by deer.

Light

Even though mahonia will grow in sun and full shade, it prefers partial shade during the hottest part of the day to filter the light.

Soil

Mahonia will be happy if you amend your soil with a few inches of organic matter. The Mississippi State Extension Service recommends adding two pounds of a 5-10-5 fertilizer per 100 square feet of planting area. Turn the soil eight to 10 inches deep.

Water

Watering your new mahonia planting in the first year is important as it becomes established. Water deeply when needed. Once the plant is established, it will grow well with rainfall, but you might need to supplement during long hot, and dry spells.

Temperature and Humidity

Mahonia tolerates the heat and humidity of our Southern climate but needs shade to thrive. Mulching around the base of the plant will help it retain water.

Fertilizer

Feed established plantings in "March with a slow-release, balanced fertilizer like an 8-8-8 at the rate of one pound per 100 square feet."

Types of Mahonia

We grow two types of mahonia in the South. The Berberis aquifolium, or Oregon Holly Grape, and Berberis bealei, or Leatherleaf Mahonia. 

Oregon Grape Holly (Berberis aquifolium)

This plant is native from Canada to Northern California and grows 6 feet or taller and 5 feet wide. Young growth is bronzy, and mature growth is green turning purple to bronze in winter, especially in the Upper South where plants are grown in full sun. It will grow best with some shade in the Lower South and wind protection Flowers grow in two to three-inch clusters along stems followed by edible, bluish-black fruit with a powdery coating. Control mahonia’s shape by pruning woody stems that jut out, cutting them back to the ground. It requires acidic soil and regular water to establish. Mahonia grows in the Upper South, Middle South, and Lower South, Zones 5-8.

• ‘Compactum’ grows 2-3 feet tall and wide.
• ‘Kings Ransom’ is an upright grower that reaches 12 feet tall and up to eight feet wide. Its dark blue-green leaves turn red-purple in winter.
• ‘Orange Flame’ grows four feet tall and five feet wide with bronze-colored new growth and glossy green mature leaves that turn the color of red wine in winter.
• ‘Soft Caress’ (Berberis eurybracteata) grows in MS, LS, and CS Zones 7-10. This thornless variety grows four feet tall and wide in part to full shade.
• Chinese Mahonia (Berberis Fortunei) grows in LS and CS Zones 7-9. This native Chinese species grows up to six feet tall and five feet wide with spiny leaves. Flowers bloom in short clusters in late summer to early fall. Grow in dappled sun to partial shade.
• Mexican Barberry (Berberis gracilis) grows most colorfully when planted in full sun with leaves that are lime-green when new, darker green in summer, and a lively mix of red, orange, yellow, and light green in winter. Grow in MS, LS, and CS Zones 7-11. It tolerates extreme heat and poor soil—even packed clay.

Leatherleaf Mahonia (Berberis bealei)

Leatherleaf mahonia is native to Asia. It is grown as an ornamental shrub in the South, but it is considered invasive in some parts of the Southeast. The evergreen shrub has holly-like, evergreen leaves with fragrant yellow flowers that bloom in late winter or early spring. It grows to five to 10 feet tall in Zones 7-9.

• Mahonia Japonica Bealei Group (Berberis bealei) grows in US, MS, LS, and CS Zones 7-9 and up to 10 feet tall and eight feet wide with strong vertical stems and horizontal foliage. The leaves are about a foot long with fragrant, spiky floral clusters in the early spring. It takes sun in US and MS Zones, but plant in part shade in other zones.
• Mahonia Oiwakensis Lomariifolia (Berberis lomariifolia) is native to Asia and grows up to 12 feet tall and 6 feet wide with erect stems. Flowers in winter or earliest spring grow in foot-long, erect clusters. Plant in the afternoon shade to maintain a deep green color. Grow in LS and CS Zones 8-9.
• Berberis x hortensisis a hybrid that grows in MS, LS, and CS Zones 7-9. Buckland and 'Charity' grow to 15 feet tall and 12 feet wide; 'Faith' reaches 10 feet tall and six feet wide; 'Hope' and 'Lionel Fortescue' grow to six feet tall and wide; 'Underway' and 'Winter Sun' reach up to five feet tall and wide.
• Texas Mahonia (Mahonia swaseyi) is native to Texas and Mexico, growing best in MS, LS, CS, and TS Zones 7-9. Leaves are rosy when young, light green in summer, and reddish purple in fall and winter. It features fragrant yellow spring flowers and bright red berries, grows best in full sun, and tolerates much heat.
• Agarita, Texas Currant (Mahonia Trifoliolata) grows six feet tall and six feet wide. It needs good drainage and full sun. Fragrant yellow flowers in spring give way to red berries that ripen in summer. Plant in MS, LS, and CS Zones 7-9.

Pruning

Pruning is a good way to shape your mahonia. Prune back branches that appear overcrowded or stems that have become leggy. Aim to remove about a third of old canes to encourage new ones to grow.

Propagating Mahonia

To propagate most mahonia plants, take cuttings in late summer after flowering or early fall before the plant flowers in winter. Here’s how:

1. Use pruners to take an unblemished six-inch cutting from this season’s growth. Cut below a node.
2. Remove lower leaves.
3. Dip the cut end of the stem into the rooting hormone.
4. Plant in a pot with moist, well-draining potting soil.
5. Cover the pot with plastic to create a greenhouse environment.
6. Place in a warm location. Keep the soil moist but not soggy until roots develop.

How To Grow Mahonia From Seed

They readily germinate (birds volunteer mahonia all over the place), but if you want to plant mahonia, regardless of species or selection, we recommend buying one from the nursery.

Potting and Repotting Mahonia

Smaller types of mahonia, like ‘Soft Caress’, are a good size to grow in pots. When growing any mahonia in a container, care for it as if it were growing in one zone colder than it is, and move the potted mahonia indoors for winter. To pot, choose a pot that is six or more inches wider than the root ball and that has drainage holes. Fill the pot with a soil mix that is well-draining. Gently loosen the roots of the root ball, and set the plant in the container. Fill in any surrounding space with soil. The top edge of the root ball should sit one inch below the container’s edge, and level the soil around it so it is even with the top of the root ball. Water the soil, and cover it with a layer of mulch.

Overwintering

Mahonia plants are cold hardy and can tolerate temperatures at 0°F to 10°F. Bring potted mahonia indoors during winter and give them indirect light and water as needed.

Common Pests & Plant Diseases

Pests and diseases are not common problems for mahonias. They are rather pest-resistant, though they can be affected by powdery mildew and rust. To prevent this, water the plant at its base rather than over its leaves. If they do occur, remove any infected foliage and treat with fungicide.

Common Problems With Mahonia

Mahonia is a relatively low-maintenance plant but it can develop rust, which presents as little brown spots on the leaves and have other problems related to overwatering and its environment. Here’s what to look for:

Leaves With Spots

Spots on the leaves may indicate rust. To prevent, water the plant at the base and keep water off of foliage. Remove infected foliage and treat the plant with fungicide.

Leaves Turning Yellow

If planted in alkaline soil, mahonia will develop chlorosis, or leaves that turn yellow. Leaves may also turn yellow when the sun exposure is too high. Check the plant’s environment and make changes as needed to give it more shade or water. Remove any yellowing leaves so the plant can redirect its energy into growing new leaves. 

Drooping Leaves

If your mahonia’s leaves are drooping or it is losing leaves, it may need less water or more sunlight.