Rhus trilobata aka Skunkbush Sumac

Rhus trilobata is an exceptionally easy plant to grow, making it ideal for low-maintenance landscapes. Once established, it is highly drought-tolerant, thriving in areas with as little as 10-20 inches of annual rainfall. The shrub adapts to a wide range of soil types including sand, loam, clay, and rocky soils, and tolerates both acidic and alkaline pH levels. It is generally pest and disease-free, requiring minimal intervention. The main consideration is providing full sun exposure and allowing adequate space for its spreading growth habit.

Rhus trilobata is extremely cold-hardy, surviving winter temperatures down to USDA Zone 3 (as low as -40°F/-40°C). This reflects its native range extending into Alberta and Saskatchewan, Canada. The shrub is deciduous, dropping its leaves in fall and entering dormancy during winter. It handles the temperature extremes of continental climates well, including hot summers in its native desert and grassland habitats. The species can grow at elevations from 500 feet up to 7,700 feet.

Rhus trilobata can be propagated by seed, softwood cuttings, hardwood cuttings, root cuttings, or division of suckers. Seed propagation is challenging due to dormancy—seeds require scarification in concentrated sulfuric acid for 60-120 minutes followed by cold stratification at 3-5°C for one month, achieving up to 93% germination compared to 5% for untreated seeds. Alternatively, fall/winter outdoor sowing allows natural stratification. Softwood cuttings taken in June-July and treated with 1000 ppm IBA have about 50% success rate. The easiest method is dividing suckers from established plants, as the species spreads readily via rhizomes.

Rhus trilobata typically reaches 2-8 feet tall and 3-8 feet wide at maturity, though some specimens can grow to 12 feet under favorable conditions with supplemental irrigation. The shrub has an upright to spreading growth habit, forming rounded, mound-like thickets. It has a medium growth rate and spreads via underground rhizomes that can exceed 20 feet in length, connecting multiple stems and forming colonies up to 30 feet in diameter. The dense crown consists of many irregularly branched stems with a taproot and fibrous root system.

Rhus trilobata is exclusively an outdoor plant, native to western North America from Alberta and Saskatchewan south through the Great Plains and western states to Texas, California, and northern Mexico. It thrives in USDA hardiness zones 3-6 and grows in diverse habitats from desert scrub to mountain forests at elevations up to 7,700 feet. It cannot be grown indoors due to its size, light requirements, and need for winter dormancy.

Yes, Rhus trilobata produces small flowers in early spring, typically in March through May depending on location. The greenish-white to creamy yellow flowers appear in terminal clusters 0.5-2 cm long, emerging 1-3 weeks before the leaves unfold. The species is dioecious, meaning individual plants are either male or female. Only female plants produce the distinctive orange-red berries after pollination by bees. The flowers are not showy but attract pollinators, and the subsequent berries persist through winter, providing wildlife value.

Rhus trilobata is dioecious, meaning male and female flowers occur on separate plants. Pollination is primarily by bees, and both male and female plants must be present for fruit production. The species is not self-fertile. After successful pollination, female plants produce hairy, sticky, orange-red drupes about 6mm in diameter that ripen from July through October. Natural seed reproduction is relatively rare due to low seed production and the requirement for compatible male and female plants in proximity.

Several botanical varieties of Rhus trilobata are recognized, including var. trilobata (the typical form), var. pilosissima (native to SW California to Kansas and NE Mexico), var. anisophylla (western US to NW Mexico), and var. simplicifolia (Colorado). Cultivated selections include 'Autumn Amber,' a compact groundcover form with excellent fall color, and 'Bighorn,' which grows to approximately 12 feet tall and twice as wide with supplemental irrigation. Note that taxonomic treatment varies—some authorities now place this species within Rhus aromatica as a variety.

When crushed, the leaves and stems of Rhus trilobata produce a strong, distinctive odor that many people find unpleasant—hence the common names 'Skunkbush' and 'Ill-scented Sumac.' However, individual perceptions vary; some describe the scent as merely pungent rather than offensive. Interestingly, the closely related Rhus aromatica has a pleasant citrus scent when crushed, which helps distinguish between the two species. The fruits themselves have a lime-like aroma and are considered pleasantly sour.

The shrub recovers vigorously from cutting or damage—after fire, it sprouts from the root crown and can grow 2-3 feet within the first year. If pruning is desired for shape or size control, it can be done in late winter or early spring before new growth begins. Historically, Native Americans would burn the plants to stimulate production of long, straight stems ideal for basket-weaving, demonstrating the plant's excellent regenerative capacity.

Rhus trilobata is generally pest and disease-free, making it a low-maintenance choice for landscapes. The primary concern is damping-off fungus, which can affect seedlings—USDA FEIS notes seedlings show 'very susceptibility to damping-off fungus,' making seed propagation challenging. Established plants are highly resistant to problems. The species is a host plant for the Luna moth (Actias luna) caterpillars, which should be considered beneficial rather than problematic. No significant insect pests or diseases affect mature plants under normal growing conditions.

As a deciduous shrub, Rhus trilobata follows a distinct seasonal cycle. New growth occurs primarily in spring and early summer, with twig growth complete by early July. Flowers emerge in early spring before leaves appear. Fruits mature from July through October and persist into winter. Leaves turn attractive fall colors before dropping in October. The plant enters dormancy through winter, requiring no special protection even in harsh climates to USDA Zone 3. Supplemental watering during establishment helps, but once established, the plant needs minimal care in any season.

The red, hairy berries of Rhus trilobata are edible and have a long history of use by Native American tribes. The tart fruits can be eaten fresh (though a bit of salt improves the flavor), dried, ground into meal and mixed with cornmeal, or made into jam. Most famously, steeping the berries in hot or cold water for 10-30 minutes creates a refreshing lemonade-like beverage—never boil them, as this extracts bitter tannins. The acidity comes from tannic and gallic acids. Only the red, fuzzy berries of sumacs are edible; avoid plants with white or yellowish berries, which may be poisonous.

Native American tribes valued Rhus trilobata for its astringent medicinal properties. Traditional uses included treating stomach ailments and digestive issues, relieving toothache pain, addressing skin conditions including poison ivy rashes, stopping bleeding, and treating head colds. The leaves were particularly used for these applications. PFAF rates its medicinal value at 2 out of 5. As with any traditional remedy, the plant should be used with caution and preferably under guidance of a qualified practitioner, as it is potentially toxic in improper preparations or doses.

Beyond food and medicine, Rhus trilobata has diverse practical applications. Native Americans wove the pliable young stems with grass to create durable, water-tight baskets—historically, plants were burned to encourage production of long, straight shoots ideal for weaving. Various plant parts yield dyes in black, brown, yellow, red-brown, and pink-tan colors. Seed oil makes excellent candles. In modern landscapes, the shrub serves for erosion control, windbreaks, and wildlife habitat. It provides food and cover for birds, game birds, deer, and small mammals, and hosts Luna moth caterpillars.

Skunkbush Sumac’s native range is Western N. America.

Skunkbush Sumac should be watered regularly, allowing the soil to dry out between waterings.

Skunkbush Sumac loves a well-draining soil. Perlite and vermiculite help with drainage, while coco coir adds organic matter, so a good potting soil mix will have all three. You can improve store-bought soil by adding some perlite to it.

Skunkbush Sumac requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Three Leaf Sumac is always in the right place to thrive.

The Skunkbush Sumac should be repotted when it has doubled in size or annually, whichever comes first. Providing fresh potting soil with all the essential nutrients each year ensures the plant's well-being, eliminating the need for fertilizer. Remember, plants derive their energy from the sun and not fertilizer.

Ploi lacks confirmed information on the toxicity of this plant. If you, a relative, or your pet accidentally consume plant material with unknown toxicity, it's best to consult a medical expert.