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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

Dichelostemma (congestum)

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: Asparagaceae
Family Common Name: Asparagus
Scientific Name: Dichelostemma congestum
Common Synonym: Brodiaea congesta
Common Name: Fork-toothed ookow
Species Code: DICO19
Ecotype: Coastal southern Oregon
General Distribution: Grows in open grassy hillsides, open woodlands, and coastal grasslands. Found in CA, OR, and WA with disjunct populations in AL and MO.
Propagation Goal: Plants
Propagation Method: Seed
ProductType: Container (plug)
Stock Type: 262 ml (16 in3) container
Time To Grow: 15 weeks
Target Specifications: Stock Type: Container seedling Root System: Firm plug in container.
Pre-Planting Treatments: Seeds are sown into trays filled with stabilized medium plugs (Q-plugs). Trays are sealed inside plastic boxes and placed into cold stratification (1 to 3 °C) for 90 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 when germination complete and secondary leaves have appeared (approximately 4 weeks following removal from stratification).
Growing medium in the transplant containers consists of 40:20:20:20 peat:composted fir bark:perlite:pumice with Nutricote controlled release fertilizer (18N:6P2O5:8K2O with minors; 180-d release rate at 21C) at the rate of 1.5 gram Nutricote per 262 ml container.
Establishment Phase: Germination is fairly uniform and is usually complete in 2 to 3 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: 3 weeks
Active Growth Phase: During the growing season, fertilization depends on weather and physiological needs. Soluble 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. Seedlings will die back later in summer.
Length of Active Growth Phase: 12 weeks
Hardening Phase: No dry-down is done to induce dormancy. Seedlings are moved to an outdoor growing area in early to mid-September.
Length of Hardening Phase: 3 weeks
Harvesting, Storage and Shipping: Harvest Date: Early October
Storage Conditions: Seedlings are usually outplanted in fall. No storage except in outdoor growing area. Plants are well irrigated prior to shipping if shipped in containers.
Other Comments: Dies back in the summer.
Perennial
This is variously classified into Asparagaceae, Themidaceae (which was placed in Asparagaceae) and Liliaceae.
References: Bonner FT, Karrfalt RB, Nisley RG, editors. 2008. The woody plant seed manual. Washington (DC): USDA Forest Service. Agriculture Handbook 727. 1223 p.

Dorena Genetic Resource Center Propagation Records, unpublished.

Integrated Taxonomic Information System [ITIS]. Dichelostemma congestum (Sm.) Kunth. URL:
https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=506944#null (accessed 7 Mar 2024).

Lady Bird Johnson Wildflower Center. Dichelostemma congestum. URL: https://www.wildflower.org/plants/result.php?id_plant=dico19

Pires JC, Keator G, Preston RE. 2019. Dichelostemma congestum. URL: https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=22850 (accessed 7 Mar 2024).

USDA Natural Resources Conservation Service. Dichelostemma congestum (Sm.) Kunth ookow. URL: https://plants.usda.gov/core/profile?symbol=DICO19 (accessed 7 Mar 2024).

Citation:

Riley, Lee E.; Kamakura, Renata. 2024. Propagation protocol for production of Container (plug) Dichelostemma congestum Plants 262 ml (16 in3) container; USDA FS - Dorena Genetic Resource Center Cottage Grove, Oregon. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/04/25). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.