Chinese mahonia is a drought-tolerant evergreen shrub that grows well in shady areas. With its holly-like leaves and mismatched tufts of yellow flowers, this plant can add interest to a garden or be grown indoors as a houseplant.
I. Appearance and Characteristics
Berberis fortunei is a species of shrub in the family Berberidaceae, the barberry family, described in 1846. It is endemic to China, found in the provinces of Chongqing, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, and Zhejiang. It is grown as an ornamental in many lands, with common names including Chinese mahonia, Fortune’s mahonia, and holly grape.
Some authorities place the genus Mahonia in Berberis because there is no definite morphological distinction between the two genera. The subject awaits in-depth genetic analysis.
Berberis fortunei was initially scientifically described and named by John Lindley in 1846. It was renamed as Mahonia fortunei by Friedrich Karl Georg Fedde in 1901 as part of the then somewhat well accepted genus Mahonia. Similarly in a 1997 paper by Joseph Edward Laferrière where he summarized the arguments that Mahonia should be synonymized with Berberis he also proposed a subspecies called Berberis fortunei var. szechuanica. As of 2023 the most commonly accepted classification is Berberis fortunei with no valid subspecies.
This is an evergreen shrub that usually grows up to 2 meters tall, but sometimes reaches 4 meters. It is upright, spreading, and somewhat rounded. It has a slow to moderate rate of growth and a moderate density. The leaves are odd-pinnately compound and alternately arranged. They are dull to dark green on top and pale yellowish green on the undersides. The blades measure up to 28 centimeters long by 18 wide. The foliage is borne in bunches at the stem tips. The inflorescence is a raceme with 4 to 10 fascicles of yellow flowers. The flowers have a sweet scent and are insect-pollinated. The fruit is a rounded purple-blue berry about half a centimeter long. The fruit is edible and acidic in flavor but it has numerous seeds. It can be eaten cooked or raw and contains a good amount of vitamin C.
This species is widely cultivated in China and in other places, such as Indonesia, Japan, and the United States.
All parts of chinese mahonia are somewhat toxic to humans when ingested due to the presence of the alkaloid berberine. The roots, stems, and inner bark have the highest concentrations of this toxin, while the fruit has the lowest concentration. Consumption of this alkaloid can result in mild to moderate illness. Symptoms of chinese mahonia poisoning include vomiting, lowered blood pressure, reduced heart rate, and lethargy. Extreme concentrations of berberine may result in altered liver function, gastric troubles, and damage to the immune cells, but this is rare.
II. How to Grow and Care
Sunlight
Chinese mahonia requires ample amounts of sunlight to maintain its brightly colored leaves with a minimum of 6-7 hours of direct sunlight. As it is remarkably tolerant of a variety of conditions, it will grow in partial sun and even under only 80% of full sun. However, when grown in shade, its colorful foliage will turn greenish.
Temperature
Chinese mahonia handles temperature extremes well, being able to survive temperatures down to -25 ℃. As it is a low feeder, it also doesn’t require much watering. Drainage is an important factor, and in a normally draining soil, you can water your chinese mahonia only when the top 5 cm of soil go dry.
Watering
Originating from regions with variable moisture, Chinese mahonia has adapted to withstand periods of low water availability, making it moderately drought-tolerant. It thrives best when its soil is allowed to dry slightly between watering sessions, which should occur once every 2-3 weeks. As an evergreen plant commonly grown outdoors, chinese mahonia’s waxy foliage aids in retaining moisture, reducing the need for frequent watering and allowing it to prosper in a variety of outdoor settings.
Soil
Chinese mahonia prefers well-drained, slightly acidic soil (6.0-6.5 pH). It can grow in all soil types (sandy, loamy and clay), but you should add certain amendments. If you are planting in quick-draining soil, mix in some peat moss or compost to improve drainage. Organic compost can also improve the acidity of your soil.
Fertilizing
For optimal health, chinese mahonia benefits from balanced nutrition fertilizers with equal NPK ratios. Apply a slow-release formula in early spring to encourage vibrant growth and again in fall to prepare for dormancy. Monthly liquid feed during growing season enhances flowering. Limit quantities to manufacturer’s recommendations to prevent root burn. Adjust seasonally: less frequent in winter. Always water soil before fertilizing to aid absorption and protect roots.
Pruning
Chinese mahonia does not necessarily require pruning, but pruning can significantly increase its vigor. Also, if planting chinese mahonia as a hedge plant, you should get an early start in properly shaping it. By trimming branches, you can thin the crown to improve ventilation and sunlight. This reduces humidity and the development of leaf pathogens (they thrive more in humid and dark places).
Pruning should be performed in spring to avoid exposing bare and growing tissues to too much moisture during autumn or frost damage during winter. Trim the old and infected branches, and branches that grow outside of the shape you desire. The golden rule is that not to cut away more than 1/3 of its canopy, and all cuts should be on a slight angle facing away from the bud. Always wear gloves when trimming chinese mahonia. Remember to disinfect your tools at the beginning to minimize the chances of cross-contamination.
III. Uses and Benefits
When planted at garden edges, the evergreen shrub chinese mahonia creates an effective security or privacy screen. Or, you can plant single bushes in small gardens where the flowers will attract butterflies, bees, hummingbirds, and songbirds. In addition, the compact nature and multiple stems of this plant make it suitable for establishing in front of taller trees.