Untitled Page
About Us
Propagation Protocol Database
Subscribe to Native Plant Journal
Print View

Protocol Information

Greg Fenchel
Natural Resources Conservation Service - Los Lunas Plant Materials Center
1036 Miller Street, SW
Los Lunas, New Mexico 87031
(505) 865-4684
(505) 865-5163

Family Scientific Name: Asteraceae
Family Common Name: Sunflower Family
Scientific Name: Chrysothamnus nauseosus
Common Name: Rubber rabbitbrush
Species Code: CHRNAU
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Container (plug)
Target Specifications: Stock Type: One-Gallon Tree Pot, 4”x4”x14”.
Root System: Consolidated root mass sufficient to prevent root ball disintegration during outplanting.
Propagule Collection: Collected in Grand Canyon National Park, Arizona.
Pre-Planting Treatments: Stratification: None required.
Seed Treatment: Bulk sowing of plumed seed with light covering.
Growing Area Preparation/
Annual Practices for Perennial Crops:

Propagation Environment: Greenhouse 70ºF day, 55ºF night during winter, maximum summer temperature 85ºF. A watering bench with mini-sprinklers automatically waters plug trays once a day in early morning. In extremely hot periods during the summer, twice a day watering is programmed. The watering bench is covered with a copper-coated fabric (Texel Forestry Fabric) to reduce root egress from the plug cells; this fabric covers a filter fabric (Dewitt Filter Fabric) which acts to pull excess water out of plug cells via capillary water movement.
Seed Propagation Method: Dry or pretreated seed are sown in plug flats with square deep cells (288 or 512 cells per flat). Media is a commercial soilless mix (Sunshine #1); plug trays are loosely filled with dry to slightly moist media, leveled off, and then compressed with an empty plug tray. The number of seed sown depends on size and estimated germination. Small or fluffy seed are dispersed as evenly as possible. Larger and more easily handled seed are sown with a goal of 2 to 5 seed per cell. Very small seed is not covered if its size will allow the seed to be washed into the media with overhead sprinkling. Larger seed with a possible light requirement are lightly covered with perlite. Fluffy seed receive a light covering of media enough to provide contact between seed and the moist plug media. Larger seed is covered with 5 to 10 mm of media.
Container Type and Volume: Ray Leach Super Cell – 10 cubic inch volume, 1.5-inch diameter, and 8.25-inch depth.
Growing Media: Mix of 2 parts Sunshine #1 or #2 with 1 part perlite. 2 to 4 kg of controlled release fertilizer (CRF) Osmocote Plus 15-9-12 incorporated per cubic yard of mix. For plants started in the greenhouse during winter, 8-9 month release CRF is used, but for spring grown material 3-4 month release CRF is used.
Establishment Phase: Sowing/Planting Technique: The filled Super Cells are dibbled to provide a hole for the plug seedling. The plug seedling root ball is removed using a flat powder spatula with a blade about 6 mm wide and 30 mm long attached to a handle. The blade is plunged along the side of root ball and the seedling plug is levered out of the cell. The plug is dropped into the dibbled hole. Top watering firms and fills any voids around the plug. If excessive numbers of seed have germinated, excess seedlings are cut off during the plug transplanting process. Must be transplanted soon after germination before radicle elongates.
Establishment Phase: The Super Cell seedlings in the greenhouse are watered with soluble fertilizer at every other watering. The fertilizer solution is Peters Peat Lite Special 20-10-20 at a rate of 200-mg/l nitrogen. Thinning of seedlings down to one per container occurs during this phase, usually when the seedlings are 2 to 4 cm tall.
Active Growth Phase: Rapid Growth Phase: Fertigation continues as described in Establishment Phase.
Hardening Phase: Hardening Phase: The goal is to have the Super Cell seedlings ready to move outside in early May after the last freeze but before excessively hot outdoor temperatures. In the outdoor nursery, larger seedlings may require watering every day, smaller seedlings generally every other day. The seedlings are fertigated about once a week with Peters Peat Lite Special 20-10-20 at a rate of 200-mg/l nitrogen.
Harvesting, Storage and Shipping: Rapid Growth Phase: Fertigation continues as described in Establishment Phase.
Outplanting performance on typical sites: Outplanting Site: Grand Canyon National Park, South Rim.
Other Comments: Moderate seedling growth, requires clipping during seedling phase to promote branching, slow later growth, low water requirement, evergreen.

Dreesen, Dave 2003. Propagation protocol for production of container Chrysothamnus nauseosus plants; Natural Resources Conservation Service - Los Lunas Plant Materials Center, Los Lunas, New Mexico. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 28 August 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.