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Native Plants Journal 5.2 (2004) 149-151


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Propagation Protocol For bareroot sagebrush (Artemisia Spp.)

Brandon Long

Horticulturist
brandonlong@utah.gov
Lone Peak Nursery
Utah Division of Forestry, Fire and State Land
271 Bitterbrush Lane
Draper, UT 84020

Edie Trimmer

Nursery Coordinator
edietrimmer@utah.gov
Lone Peak Nursery
Utah Division of Forestry, Fire and State Land
271 Bitterbrush Lane
Draper, UT 84020
Keywords
nursery, Asteraceae, fertilization, cultural practices
Nomenclature
USDA NRCS (2004)

Click for larger view		 Photo by Brandon Long

Because of drought, maturity, and urban expansion, sagebrush areas throughout the State of Utah have been declining. Precipitation for the past 5 y has been only half of normal. Decline of sagebrush communities has been of primary concern for wildlife specialists. Recently, the Utah Division of Wildlife Resources has focused efforts on restoration of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]), but that is only one of several subspecies of A. tridentata that occurs throughout the state.

The Lone Peak Conservation Nursery staff has worked for many years to develop reliable and predictable propagation protocols for big sagebrush. Propagation trials began in 1990 for mountain big sagebrush (A. tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) and in 1995 for Wyoming big sagebrush. This work owes much to the early efforts of former managers John Justin (currently manages State of Montana Conservation Seedling Nursery) and Scott Zeidler (Community Forester, Utah Division of Forestry, Fire, and State Lands). It has also benefited greatly from collaboration with John Fairchild and Scott Walker of the Utah Division of Wildlife Resources, Ephraim Seed Warehouse, and Steve Monsen of the USDA Forest Service Shrub Sciences Laboratory in Provo, Utah.

We grow about 65000 sagebrush seedlings annually as a 1+0 crop. Most have been used by the Utah Division of Wildlife Resources for replanting efforts in areas where direct seeding is impractical or has been unsuccessful because of drought conditions. In addition to Wyoming and mountain big sagebrush, we grow basin big sagebrush (A. tridentata Nutt. ssp. tridentata).

Seed Acquisition

Two problems facing growers of A. tridentata are the small size (5.5 million/kg [2.5 million/lb]) and poor quality of seeds. Most lots purchased by Lone Peak [End Page 149] have average purity rates of 13% and germination rates < 50%. Purity rates > 10% are considered acceptable. Big sagebrush seed must be collected in late fall or early winter. Collections are typically done by hand using clubs or tennis rackets to dislodge achenes before gathering them into sacks or hoppers (see Jensen 2004). Viability rates decrease sharply after the first year so seeds are sown the first spring following collection and any unused seed remaining after the second spring is discarded.

In the first years of production, Lone Peak Conservation Nursery relied on NRCS-released varieties of seeds for mountain big sagebrush (Hobble Creek) and Wyoming big sagebrush (Gordon Creek). Since 1994, we have purchased and used seeds identified by collection area by seed vendors in addition to the Hobble Creek and Gordon Creek varieties. Unfortunately, the exact location and elevation of seed collection is often difficult to obtain from vendors.

Field Treatments

Our soils are a mosaic of Taylorsville sandy clay loam and clay loam with a calcareous horizon with pH that ranges from 6.5 to 8.9. In some field locations, this horizon occurs at depths less than 30 cm (12 in). We generally plow, disc, and rototill our soil before forming beds. Prior to rototilling and based on soil tests, we apply prill sulfur at a target rate of 900 kg/ha (800 lb/ac) as a precautionary buffer. At the time of bed formation, we incorporate phosphorus (0N:45P2O5:0K2O) at 448 kg/ha (400 lb/ac).

During the past 12 y we have tried several sowing methods, but two provided the most satisfactory results. With either method, we sowed nonstratified seeds. Because we have access to inmate labor, we used crews to hand-plant seeds. We used a Love/Øyjord seed drill, with the packing wheels...

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