Smooth sumac (Rhus glabra)

Overview

Rhus glabra, commonly known as Smooth sumac, is a robust and adaptable native shrub valued for its striking ornamental features throughout multiple seasons. This plant establishes quickly, forming large, spreading thickets through root suckers, making the larger colonies a dramatic presence in native plantings. Gardeners appreciate the fern-like appearance of its compound leaves, which transform into vibrant shades of bright orange and red shades in autumn.

A key feature appreciated by wildlife enthusiasts is the persistent, showy fruit clusters produced by female plants, which remain attractive long into the winter months. Smooth sumac thrives in difficult settings, tolerating poor soils and drought once established, which adds to its practicality in landscape restoration or challenging sites. While its aggressive spreading nature requires careful placement, its combined appeal of foliage, flower, and fruit makes Rhus glabra a valuable naturalizing component.

Fast Facts

• Plant Family: Anacardiaceae
• Plant Type: Deciduous shrub
• Native Range: Northeastern United States to southern Canada
• Hardiness Zones: USDA Zones 3-9
• Size at Maturity:
  • Height: 9-15 ft
  • Spread: 9-15 ft
• Bloom Time: June
• Bloom Description: Yellowish-green
• Sun Exposure: Full sun to part shade
• Water Needs: Dry to medium
• Maintenance Level: Medium

How to Grow

Plant Rhus glabra in average soil conditions, ensuring that the site provides good drainage, as it will not tolerate consistently poorly drained locations. The ideal location is one that receives full sun, although it will tolerate partial shade. Since Smooth sumac is extremely adaptable, it establishes well in dry soils once past initial establishment.

Watering requirements are low to moderate; deep watering encourages establishment, but established plants are highly drought-tolerant. Minimal supplemental fertilization is usually required, especially if the goal is to encourage naturalized growth. Due to its aggressive spreading habit, prune only if necessary to control size or shape, focusing on removing unwanted suckers that venture outside the desired area.

This tough shrub performs well in various challenging settings across its hardiness range. It is best utilized where soil conditions are drier or shallower, making it an excellent choice for stabilizing slopes or covering difficult, exposed areas.

Landscape Uses

The strong spreading nature of Smooth sumac makes it functionally superior for mass planting projects. Consider utilizing Rhus glabra extensively for stabilizing embankments where erosion control is critical, or for quickly covering large, otherwise hard-to-manage areas with tough, low-maintenance vegetation. Its aggressive colonization habit means it should generally be avoided in formal shrub borders or small, manicured beds where spread cannot be tolerated.

When used appropriately, the ornamental value of this species shines. The feathery foliage provides excellent texture contrast against fine-bladed grasses or shrubs with dense habits. For an engaging fall display, plant Rhus glabra near evergreen conifers or deciduous plants that display purple or yellow fall color for maximum visual impact.

Standout Features

Flower Qualities

• Showy

Fruit Qualities

• Showy

Noteworthy Characteristics

Rhus glabra, commonly called smooth sumac, is a Missouri native, deciduous shrub which spreads by root suckers to form thickets or large colonies in the wild. It is easily distinguished from staghorn sumac because the young stems of this species are smooth, hence the common name. Foliage provides strong textural interest and turns bright orange to red in autumn, complemented by showy, persistent red fruit clusters on female plants through winter.

Tolerances

• Rabbit
• Drought
• Erosion
• Dry Soil
• Shallow-Rocky Soil
• Black Walnut

Potential Problems

Smooth sumac generally exhibits good health, presenting few serious insect or disease issues in well-suited environments. However, under stress or in overly humid conditions, gardeners may observe some susceptibility to common issues like leaf spot or rust, and occasionally see scale insects, aphids, or mites. The primary management concern for Rhus glabra is its tendency to spread aggressively via suckers. Proactive containment strategies, such as managing root spread beneath hardscaping or diligent removal of suckers, are necessary if you prefer a more controlled specimen.

Frequently Asked Questions

What hardiness zones is Smooth sumac suitable for?

Rhus glabra is highly adaptable and performs well across USDA Zones 3 through 9.

How large does Smooth sumac grow?

This deciduous shrub typically reaches a mature height and spread between 9 to 15 feet tall and wide as it forms large colonies.

What sun exposure does Rhus glabra need?

Rhus glabra prefers full sun but demonstrates good tolerance for part shade conditions in the landscape.

When does Smooth sumac bloom?

Flowering generally occurs in June, producing tiny, yellowish-green flowers.

Conclusion

Rhus glabra, or Smooth sumac, remains a top choice for ecological landscaping due to its hardiness, excellent fall coloration, and value to regional wildlife. Its ability to thrive in dry, poor soils makes it a functional asset where other plants might fail. Before planting, assess your space to accommodate its eventual size and spreading nature, ensuring this vigorous native shrub provides years of low-maintenance beauty.

Wildlife Benefits

The dense, spreading thickets formed by Smooth sumac offer excellent cover and nesting locations for various small birds throughout the year. The most significant ecological benefit, however, comes from the fruit. Female plants produce dense, pyramidal clusters of hairy drupes that ripen red in autumn and persist into early winter. These fruits are a crucial, late-season food source highly attractive to numerous bird species when other food sources become scarce.

Planting Rhus glabra in naturalized areas directly supports local fauna, especially during the lean months of winter. While the foliage provides structure, it is the long-lasting persistent fruit that truly elevates this shrub’s role in the wildlife garden.

Propagation Tips

Successfully managing Rhus glabra populations often involves intentionally encouraging established clumps, or conversely, managing suckering. The most straightforward method of increasing your plant stock or repairing damaged areas is through the division of root suckers during the dormant season (late fall or very early spring). Carefully dig around a vigorously growing sucker, severing it from the parent plant’s root system while retaining a substantial section of roots.

Alternatively, seed collection is possible, though germination can be erratic without proper cold stratification. The hairy seeds must be collected after they turn color in the fall and then subjected to a period of cold, moist stratification before spring planting to break dormancy and encourage sprouting.