Hemlock Rehabilitation Demonstration Project
The demonstration project began in 2012 as part of an effort to identify the best techniques for the restoration of heavily infested poison hemlock vegetation sites. Restoration projects adjacent to streams and springs in the Lapwai Creek watershed are necessary to improve steelhead habitat along the streams. Springs within the lower Lapwai system contribute significantly to lower stream temperatures and have been documented to be areas of high juvenile steelhead densities. The majority of the springs are heavily infested with invasive species. In order to restore native vegetation to these ecosystems the noxious and invasive plants need to be suppressed. The field trial and demonstration will focus on poison hemlock control and revegetation. The NPSWCD identified poison hemlock as one of the top three weeds (along with reeds canarygrass and knotweed) to control prior to restoration.
Figure 1. Hemlock Demonstration Project Site
The demonstration project is located on private lands along South Tom Beall Road. The site was selected due to the density of hemlock as well as the ease of access for treatment and evaluation. The site can be viewed from South Tom Beall Road. Please remember that the site is privately owned and to obtain access to the site requires land owner permission. The NPSWCD recommends that interested parties either view the site from the road or contact our office at 208-843-2931 to obtain permission.
Figure 2. 2012 treatment map
In 2012, areas were designated for spraying, mowing, mowing and spraying, and no treatment. These areas are roughly illustrated in the image below. The mowing was performed with weed eaters, while the spraying was completed using backback sprayers with metsulfuron methyl (1 gram / gallon) and glyphosate. The first treatment was on May 30, 2012 and the second on August 20, 2012, the third on June 10, 2013 and the fourth on June 4, 2014. Part of the site was cultivated in November 2014, then harrowed using an ATV and drag harrow in February 2, 2015 and broadcast seeded using hand seeders on February 4, 2015. The grass species used included Idaho Fescue, Secar Bluebunch Wheatgrass, Sherman Big Bluegrass, and Magnar Basin Wildrye.
A variety of trees and shrubs were planted in December 2014 and February 2015. These shrubs are planted in rows with either weed barrier or no barrier. The rows are numbered with signs attached to fence posts. The species planted include sage (3 types), winterfat, four wing salt bush, syringe, ponderosa pine, basin wildrye, rose, sumac (2 types), and mountain mahogany (2 types). The plants will be monitored for survival over time.
See a photo gallery a photo gallery of this project below.