Hulls Gulch Reserve Vegetation Management

The goal of this work is to reduce invasive species taking over sensitive wetland areas in Hull Gulch Reserve. The project will also reduce fuels from the landscape for wildfire mitigation and create open spaces to restore native plants to the area. Fire officials and restoration leaders have identified this area as a high priority due to its popularity, presence of wetlands, and the pervasive nature of invasive roses and shrubs present at the Grove Trailhead. Additionally, the City of Boise has received grant funding for fuel reduction that can be applied to this work.

To reduce soil disturbance, the project is being completed during the winter months when the soil is frozen. Native plantings will be added in the spring to rehab the site and support wildlife.

For the purposes of this project, a masticator is a piece of heavy equipment – like a skid steer or excavator – with an attachment head that consists of a rotating drum and teeth that shreds, grinds, and chops woody vegetation into fine mulch. It works similar to a woodchipper.

When crews are on-site using the masticator in Hulls Gulch, community members can expect to see large equipment working near the Grove Trailhead. Masticators are heavy machinery, and those in the immediate vicinity can expect to hear the high-speed rotating drum cutting up and removing brush. Crews will use all required safety equipment and precautions, and work will only happen during daylight hours.

Trails adjacent to the project area will be closed while contractors are working as a safety precaution. Masticators can throw woody materials, rocks, and debris up into the air while operating and this is a hazard for trail users in the area. Sections of nearby trails (the Connector, Goldfinch and the Grove) will be closed for safety purposes and closures will be marked with signs indicating no access. The Grove Trailhead will also be closed temporarily because the existing fence needs to be removed to grant access to invasive roses that now cover the fence. The fence will be replaced soon after the project is over with buck fence (also known as jack-leg) fence.

Mastication is a mechanical management technique that shreds brush and downed vegetation, or “slash” into small pieces (mulch) that is left on-site.

Mastication is used to reduce hazardous fuels by breaking down large amounts of brush and trees and then converting them into mulch. The removal of “ladder fuels” (vegetation connecting the ground to tree canopies) lowers the intensity of potential fires. Mastication is also a useful tool to improve wildlife habitat because it can be used to remove invasive shrubs and clear overgrown areas for future restoration treatments with native plants.

Many non-native shrubs are prominent and outcompeting native plants near the Grove Trailhead in Hulls Gulch. The most common are invasive roses include dog rose (Rosa canina), round-leaved rose (Rosa obtusifolia), and eglantine rose (Rosa rubiginosa). Other non-native shrubs include European privet (Ligustrum vulgare) and Callery pear (Pryus calleryana). These invasive shrubs form dense monocultures – a large, often complex area covered with one species of plant— and displace native plants that our local wildlife relies on. Only invasive roses and other shrubs will be masticated as a part of this project. Every effort will be made to preserve all native plants on the project site.

Invasive roses can grow over 15 feet high and 10 feet in diameter. They also have large prickles that make hand removal of these shrubs extremely challenging for people using hand tools. It can take hours for an individual to reach the base of the shrub to begin the removal process. Using machinery is more efficient and effective for treating dense rose monocultures found near sensitive wetlands in the Boise Foothills.

Wood’s rose (Rosa woodsii) can be found in Hulls Gulch and has slender prickles and forms open thickets. Most of the non-native roses have thick curved prickles and have arched stems that can reach over 15 feet tall and form a single clump. The goal and focus of this project is to remove only invasive roses and shrubs in Hulls Gulch to give native plants and wildlife a chance to thrive through restoration and care.

After the fuel reduction project is completed in February 2026 (weather-permitting), the site might look bare. Please rest assured that more than 120 native shrubs seedlings will be planted in March 2026 as well as 35 five-gallon cottonwood and coyote willow trees. The roses will resprout and continued removal of resprouting invasive rose will be imperative to project success. This will be monitored and overseen by Boise Parks and Recreation’s restoration team, led by Foothills Restoration Specialist Martha Brabec.

Check out these online resources:

• Rocky Mountain Research Station Bulletin, “Is Mastication Right for Your Site? Science-Based Decision Trees for Forest Managers” - https://ucanr.edu/sites/default/files/2020-11/340142.pdf
• United States Department of Agriculture Publication, “To Masticate or Not: Useful Tips for Treating Forest, Woodland, and Shrubland Vegetation” -https://www.fs.usda.gov/rm/pubs_series/rmrs/gtr/rmrs_gtr381.pdf
• Pennsylvania State University Publication, “'Tis The Season - Winter Invasive Plant Control” - https://extension.psu.edu/tis-the-season-winter-invasive-plant-control

You can email Boise Parks and Recreation or call us at (208) 608-7600 option 1 (TTY: 711).