Skunkbush Sumac (Rhus trilobata)

Noted for its 3 seasons of interest, Rhus trilobata (Skunkbush Sumac) is an upright arching deciduous shrub forming rounded, moundlike, or upright thickets. The leaves of the skunk-bush sumac (Rhus trilobata) have a pungent smell, hence its name. The berries provide food for animals and birds in winter. Many of those creatures also make use of skunk-bush sumac as shelter. The flexible branches can be woven into baskets.

I. Appearance and Characteristics 

Rhus trilobata is a shrub in the sumac genus (Rhus) with the common names skunkbush sumac, sourberry, skunkbush, and three-leaf sumac. It is native to the western half of Canada and the Western United States, from the Great Plains to California and south through Arizona extending into northern Mexico. It can be found from deserts to mountain peaks up to about 7,000 feet (2,100 m) in elevation.

This Rhus species closely resembles other members of the genus that have leaves with three “leaflets” (“trifoliate” leaves). These include Rhus aromatica, native to eastern North America, and western poison-oak. The shape of the leaflets and the habit of the shrub make this species, like some other Rhus, resemble small-leafed oaks (Quercus).

The Rhus trilobata leaves have a very strong scent when crushed. The aroma is medicinal or bitter, disagreeable enough to some to have gained the plant the name skunkbush. The leaves are green when new and turn orange and brown in the fall. The twigs are fuzzy when new, and turn sleek with age. The flowers, borne on small catkins (“short shoots”), are white or light yellow. Edible fruit, the plant yields hairy and slightly sticky red berries which have an aroma similar to limes and a very sour taste. The acidity comes from tannic and gallic acids. The flowers are animal-pollinated and the seeds are dispersed by animals that eat the berries. The shrub also reproduces vegetatively, sending up sprouts several meters away and forming thickets.

II. How to Grow and Care

Skunk-bush sumac is a resilient and low-maintenance plant suited to a variety of garden conditions. It thrives in full sun and requires well-draining soil, making it ideal for xeriscaping. Occasional pruning to maintain shape and remove dead branches is recommended. Skunk-bush sumac is drought-tolerant once established, but young plants benefit from regular watering until they take root. Care for skunk-bush sumac is uncomplicated, making it suitable for novice gardeners.

Sunlight

Skunk-bush sumac prefers full sun, but can also be grown in slight shade. It is recommended to plant it in a more open location that can provide it 6 or more hours of sunlight per day. When it gets adequate light, its leaves turn beautiful bright red or orange-yellow in fall.

Temperature

Skunk-bush 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 ℃. Skunk-bush 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

Adapted to arid environments, skunk-bush sumac thrives with minimal moisture, exhibiting a strong drought tolerance. This resilience is mirrored in its watering needs, requiring hydration once every 1-2 weeks. Cultivated primarily outdoors due to its robust nature, skunk-bush sumac benefits from well-draining soil that emulates its native dry conditions.

Soil

Skunk-bush 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. Skunk-bush sumac can grow in poor gravelly soil under drought, but naturally, rich, fertile and well-drained soil is better for its growth.

Fertilizing

Fertilize skunk-bush sumac sparingly with balanced nutrition fertilizers in spring to boost vigour. A higher nitrogen formula can enhance growth if leaves show yellowing. Limit fertilization to once per season, as skunk-bush sumac thrives in lean conditions. Over-fertilization can harm[ N] and its native ecosystem. Adjust fertilization based on growth stage and seasonal changes. Use recommended rates on product labels, applying at the plant’s drip line. For new growers, it’s imperative to follow label instructions and for seasoned gardeners, observing skunk-bush sumac’s response to fertilization can guide future applications.

Planting Instructions

Transplant skunk-bush 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

Skunk-bush sumac does not require much pruning. Pruning some of the lower and side branches in winter to early spring is fine. During this period, skunk-bush sumac grows slowly, so pruning has less impact on the tree. Not only does pruning reduce wasted nutrients and promote plant growth, but it also helps the emergence of strong new branches in the following year, as well as gradual crown renewal. In daily maintenance, prune branches that are dry, overgrown, or infected with pests and diseases.

Propagation

This resilient shrub native to North America flourishes in various conditions and thrives with minimal care. For successful propagation, skunk-bush sumac can be started from seeds, ideally following a period of cold stratification to simulate winter, enhancing germination rates. Semi-hardwood cuttings taken during periods of active growth can also be rooted with a rooting hormone for more controlled multiplication. Ensure growing mediums are well-draining and start the seeds or cuttings in a sheltered environment before transplanting to their final location.

Transplanting

Transplant skunk-bush sumac during the warmth of post-frost season for better root establishment. Choose a sunny location with well-drained soil. Gentle handling of the root ball is crucial for successful transplantation.

III. Uses and Benefits 

• Ornamental uses

Perfect as a windbreak or hedge, for erosion control, and as an ornamental. Can be pruned into a more compact, rounded form for background or specimen plantings.

• Other uses

The berries are an important food source in winter for many birds and some small mammals.

The skunkbush sumac has historically been used for medicinal and other purposes. The bark has been chewed or brewed into a drink for cold symptoms, the berries eaten for gastrointestinal complaints and toothache, and the leaves and roots boiled and eaten for many complaints. The leaves have also been smoked.

The flexible branches were useful and sought after for twisting into basketry and rugs. The berries, although sour, are edible. They can be baked into bread or mixed into porridge or soup. Steeped, they can make a tea or tart beverage similar to lemonade. The fruit can also be eaten directly, although a bit of salt may improve the flavor.

According to Marvin Johnson Jr, a Mono native from Cold Springs Rancheria (a federally recognized tribe from Tollhouse, California), the fruit will last all year long if you have flats full and dry them out. He goes on to say, once you’re ready to eat them, just add a little moisture.

It is sometimes planted for erosion control and landscaping, and is a plant used for reclaiming barren land stripped by mining.

The Zuni people, Navajo, Mono tribe of California and tribes in the area use the stems with the bark removed to make baskets.

The Uncompahgre Ute name for the berries is mah wup, and the bush is called ece.

IV. Harvesting and Storage

Collect skunk-bush sumac seeds in the fall when the fruits turn red. Collect, wash, and dry the seeds and store them in a dry, cool place.