Rhus chinensis, also known as the Chinese sumac or nutgall tree, is a deciduous tree that can reach a height of 6 meters. This hardy plant thrives in zones 8 and above, and its enchanting flowers bloom in August, followed by ripening seeds in October.
I. Appearance and Characteristics
Rhus chinensis, the Chinese sumac or nutgall tree, is a deciduous shrub or small tree in the genus Rhus. Growing to 6 m (20 ft) tall, it has downy shoots and leaves comprising several leaflets. These turn red in autumn before falling.
The plant is common in East and South Asia, and is cultivated as an ornamental in temperate climates.
Galls produced on the species that are called Chinese gall (Galla chinensis), are a source of gallotannins, molecules of hydrolyzable tannins. Infestation of the tree by Chinese sumac aphids (Melaphis chinensis Bell) may lead to production of a gall that is valued as a commercial product in China.
Chinese galls are used in traditional Chinese medicine for coughs, diarrhea, night sweats, dysentery, and intestinal and uterine bleeding. Some research has suggested that chemical compounds found in Rhus chinensis possess in vitro antiviral, antibacterial, anticancer, hepatoprotective, antidiarrheal, and antioxidant activities. However, this evidence is not substantiated by multiple international researchers. The aqueous extracts of the gall also inhibit alpha-glucosidase activity in vitro.
II. How to Grow and Care
Chinese sumac is renowned for its resilience and straightforward care requirements, making it accessible for gardeners of varying experience levels. Key points include ensuring the plant gets full sunlight to partial shade and it thrives in well-draining soil. One special care point is to manage its potential invasiveness, as chinese sumac can spread vigorously if not kept in check.
Sunlight
Chinese sumac is a sun-loving plant that prefers bright, full sun locations for optimal growth. In its natural range, Chinese sumac receives around 6-8 hours of sunlight each day during the growing season. During the warmer months, it can tolerate up to 10-12 hours of sunlight per day, although it should not be exposed to direct, intense afternoon sunlight. In cooler climates, Chinese sumac should be given at least 4-6 hours of direct sunlight daily.
Temperature
Chinese sumac is distributed throughout temperate and subtropical regions, and prefers warm, humid conditions. It is hardy to cold and can tolerate low temperatures of -7 ℃. Chinese sumac can tolerate some drought but not standing water, so do not plant it in low-lying locations. In rainy seasons or locations, pay attention to soil drainage to prevent root rot.
Watering
Chinese sumac should be watered when the top inch or 2 of soil feels dry to the touch. This is typically every 1-2 weeks, although watering frequency can vary depending on the environment and season. Water until the soil is saturated, and allow the excess water to drain away. Avoid over-watering, as this can cause root rot in the plant.
Soil
Chinese sumac is adaptable and can grow in many types of soil. It prefers slightly acidic to neutral soil of pH 5.5-7.5, but can adapt to mildly alkaline soil. Chinese sumac can grow in poor gravelly soil under drought, but naturally, rich, fertile and well-drained soil is better for its growth.
Fertilizing
For the thriving growth of Chinese sumac, fertilizing with balanced nutrition fertilizers is quintessential. This encourages vigorous health, boosts fruit production, and fortifies the plant. Apply a balanced 10-10-10 NPK fertilizer biannually, during spring growth and pre-fall. Quantity should align with product guidelines and plant size. During dormant winter periods, fertilization is unnecessary. Over-fertilization can harm, so follow instructions precisely. Liquid formulations ease application and control. For effective nutrient uptake and safety, water chinese sumac prior to applying fertilizers.
Planting Instructions
Transplant chinese sumac before it sprouts in spring or after leaves falling in fall. Start by digging a pit in a sunny, elevated place. The pit should be as deep as the height of the root ball, and wider than its width. These dimensions give the roots enough space to grow. Once planted, compact the soil and water deeply. Generally, the plant doesn’t need watering again after new buds sprout.
Pruning
Chinese sumac should be pruned in late winter or early spring. Pruning for this species should be light and selective, focusing on removing damaged, diseased, or dead wood and weak growth. This will help to encourage an overall healthy form. Additionally, cutting back some of the longer stems to a higher bud can encourage bushier growth and more flowers.
Propagation
Chinese sumac is a versatile shrub well-suited for gardens. Propagation success involves sowing seeds that have undergone stratification to break dormancy, ensuring better germination. Cuttings can also be used; however, they should be treated with a rooting hormone and planted in a well-draining, sterile medium to foster root development. Careful attention to soil moisture and warmth will help in establishing a robust root system, vital for the plant’s growth.
Transplanting
The prime time to transplant chinese sumac is during the temperate embrace of late spring, ensuring robust root establishment before the heat of summer. Choose a sunny spot with well-drained soil. If needed, amend the soil with organic matter to promote healthy growth.
III. Uses and Benefits
- Ornamental uses
Rhus chinensis also presents excellent ornamental features. Its shiny dark green summer foliage, flower panicles in late summer, fruiting clusters in fall, and vibrant autumn colors make it a stunning addition to any landscape. However, it should be noted that due to its aggressive and weedy nature, it is best suited for dry, informal, and naturalized areas where it can spread and form colonies. It is perfect for erosion control on slopes or in areas with poorer soils, and it harmonizes beautifully in open woodland areas, wood margins, and wild spaces.
- Medical uses
In traditional herbal medicine, different parts of Rhus chinensis are utilized for their therapeutic properties. The seed is used to treat coughs, dysentery, fever, jaundice, malaria, and rheumatism. Leaves and roots are considered depurative and stimulate blood circulation. A decoction of Rhus chinensis is commonly used to treat haemoptysis, inflammations, laryngitis, snakebite, stomach-ache, and traumatic fractures. The stem bark acts as an astringent and anthelmintic, while the fruit is used to alleviate colic. Galls found on the plant are known for their astringent and styptic properties, making them effective in the treatment of conditions such as diarrhea and hemorrhage.
IV. Harvesting and Storage
Collect chinese sumac seeds in the fall when the fruits turn red. Collect, wash, and dry the seeds and store them in a dry, cool place.
