Late Spring/Early Summer Brush Control

Across Kansas rangeland and pasture acres, three native shrub species are becoming increasingly common: buckbrush, roughleaf dogwood, and smooth sumac. While each plays a role in the ecosystem, unchecked growth can reduce forage production and limit grazing efficiency. Understanding how to identify and manage these species is key to maintaining productive pastures.

Buckbrush is a low-growing shrub that can reach over six feet in height and spreads aggressively through rhizomes and stolons. It is commonly found in disturbed woodlands, along creek banks, old fields, and in pastures. With opposite leaves and red fruit produced in late summer, it is relatively easy to identify during the growing season. However, its tendency to form dense colonies allows it to outcompete desirable grasses and forbs.

Roughleaf dogwood, a larger shrub that can grow up to 15 feet tall, is often found along fencerows, streambanks, and woodland edges. It produces clusters of white flowers in late spring, followed by white berries in the fall. While it provides valuable wildlife habitat and cover for birds, it can become problematic in grasslands where fire is absent, gradually encroaching and reducing forage availability.

Smooth sumac is another widespread shrub, typically growing 5 to 7 feet tall. It is easily recognized by its compound leaves and bright red fall color, along with its distinctive seed heads that resemble milo. Found on rocky soils, fencerows, and pastures, smooth sumac also provides some wildlife value but can quickly form dense stands.

A common challenge with all three species is their ability to form thick clumps that shade out herbaceous vegetation. Most cattle avoid grazing these shrubs, allowing them to spread further. Sheep and goats may utilize them more readily, but grazing alone is rarely sufficient for control.

Effective management begins with early detection and a planned approach. For buckbrush, mechanical methods such as mowing can be useful if timed correctly. Cutting after leaf-out, when root energy reserves are low, can weaken the plant. However, a single mowing is not enough—multiple cuttings or consecutive years of prescribed burning in late spring are often needed for meaningful control.

Herbicide applications are another option for buckbrush, with the best results occurring when plants are fully leafed out but not yet mature, typically from mid-May to early June. Several herbicide combinations are effective, but producers should always follow label directions and consider potential impacts on desirable species.

Roughleaf dogwood presents a different challenge. It thrives in the absence of fire, and research has shown that infrequent burning allows populations to increase significantly. Annual late-spring burning can help suppress its spread, though established stands are difficult to eliminate with fire alone. Herbicide treatments can reduce top growth, but complete control often requires a multi-year strategy combining burning and follow-up applications after regrowth.

Smooth sumac is generally easier to control compared to the other two species. While late-spring burning can reduce plant height, it may increase stem density. Herbicide applications made between the flower bud stage and early seed development are typically very effective, especially when coverage is adequate.

In addition to foliar sprays, soil-applied herbicides can be used in certain situations, particularly where drift from spraying is a concern. These products can provide control of roughleaf dogwood and smooth sumac, though care must be taken to avoid damage to desirable vegetation downslope.

Growing-season burns, including those conducted in August, may also help reduce populations of roughleaf dogwood and smooth sumac over time.

Ultimately, managing these native shrubs requires a combination of methods and a long-term commitment. No single treatment will provide complete control, but integrating fire, mechanical practices, and herbicides can restore balance and improve forage production.

As always, when using herbicides, consult the product label for the most current recommendations and application guidelines.

Lonnie Mengarelli is a Kansas State University Extension Agriculture agent assigned to the Southwind District. He may be reached at [email protected] or 620-223-3720