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The Forest Service National Center for Reforestation, Nurseries, and Genetic Resources (RNGR) is a leading source of technical information for nurseries and land managers regarding production and planting of trees and other native plants for reforestation, restoration, and conservation.

 
NPN Protocol Details Image

Rubus (parviflorus)

Lee Riley
Horticulturist
USDA FS - Dorena Genetic Resource Center
34963 Shoreview Road
Cottage Grove, Oregon 97424
541-915-7324
541-767-5709 (fax)
lee.riley@usda.gov
Family Scientific Name: Rosaceae
Family Common Name: Rose
Scientific Name: Rubus parviflorus
Common Name: thimbleberry
Species Code: RUPA
Ecotype: Deschutes, Mt Hood, Rogue River-Siskiyou, Siuslaw, Umpqua, Willamette National Forests, Oregon
General Distribution: R. parviflorus is found in moist to dry, wooded to open areas from near sea level to the subalpine zone; from Alaska to southern California, and inland from the coast to the Great Lakes, and through the Rocky Mountains from Alberta to northern Mexico.
Propagation Goal: Plants
Propagation Method: Seed
ProductType: Container (plug)
Stock Type: 444 ml (27 in3) container
Time To Grow: 18 weeks
Target Specifications: Stock Type: Container seedling Root System: Firm plug in container.
Propagule Collection: Seed is collected in late August when fruits are bright red and are easily pulled from hypanthium disk. Seeds are tan at maturity.
Berries can be stored in a plastic bag at ~4 °C until extraction, within two weeks or so to prevent mold growth.
Propagule Processing: Macerate berries thoroughly while still in plastic bag. Add water to bag to mix, and pour mixture in beaker. Add sufficient water. Water to berry mixture should be 3:1. Add pectinase (approximately 1 table spoon per liter) to volume and stir. Leave mixture at room temperature for 24 hours. Most seed should sink to bottom if filled and properly macerated initially. Pour off top layer of while gently mixing, or adding water from a faucet. Do not mix so violently that seed rises in the water column, but just enough that berry skin begins to float and pour off the non-seed debris. When seed is as clean as possible, pour wet seed onto paper towel and allow to dry. Pick out debris with tweezers. Dry to <38% RH. Store at 4 °C.
Pre-Planting Treatments: Due to small seed size, the easiest method is to sow seed into trays filled with stabilized medium plugs (Q-plugs). Trays are sealed inside plastic bags and placed into refrigeration at 1 to 3 °C for 120 days. Trays are checked weekly and kept moist throughout the stratification period. If mold is evident, trays should be treated with 1% hydrogen peroxide.
Growing Area Preparation/
Annual Practices for Perennial Crops:		 Greenhouse growing facility.
Q-plugs are lightly covered with nursery grit. Seedlings are transplanted to target containers approximately 3 weeks following removal from stratification.
Growing medium used is 40:20:20:20 peat:composted fir bark:perlite:pumice with Apex controlled release fertilizer (16N:5P2O5:10K2O with minors; 6 to 7 month release rate at 21C) at the rate of 2 gram Apex per 444 ml container.
Establishment Phase: Germination is fairly uniform and is usually complete in 2 weeks. Following germination (while still in Q-plugs), plants are fertilized with soluble 12-2-14-6Ca-3Mg at 75 to 100 ppm for 2 weeks.
Length of Establishment Phase: 2 to 3 weeks
Active Growth Phase: Plants grow rapidly following establishment, and may need to be top-pruned 3 months following transplanting into the target container. Soluble fertilizer (20-9-20 NPK, 20-18-18 NPK, or 17-5-24 NPK) at 100 to 150 ppm is applied weekly throughout the growing season.
Length of Active Growth Phase: 15 weeks
Hardening Phase: No dry-down is done to induce dormancy. Seedlings are moved to an outdoor growing area in early September.
Length of Hardening Phase: 2 to 3 weeks
Harvesting, Storage and Shipping: Harvest Date: Mid to late October
Storage Conditions: Seedlings are usually outplanted in fall. No storage except in outdoor growing area. Plants are well irrigated prior to shipping and shipped in containers.
Other Comments: Wetland classification: FACU
References: Dorena Genetic Resource Center Propagation Records, unpublished.

USDA Natural Resources Conservation Service. Rubus parviflorus Nutt. thimbleberry. URL: https://plants.usda.gov/core/profile?symbol=RUPA (accessed 11 Oct 2018).

Citation:

Riley, Lee E.; Smith, Haley S.; Klocke, Allison. 2018. Propagation protocol for production of Container (plug) Rubus parviflorus Plants 444 ml (27 in3) container; USDA FS - Dorena Genetic Resource Center Cottage Grove, Oregon. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/02/24). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.