Crossosoma (californicum)

Michael Herrera Nursery Manager Catalina Island Conservancy PO Box 2739 Avalon, California 90704 (310) 510-2904 (310) 510-3157 (fax) mherrera@catalinaconservancy.org www.catalinaconservancy.org

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Family Scientific Name:	Crossosomataceae
Family Common Name:	Crossosoma Family
Scientific Name:	Crossosoma californicum Nutt.
Common Name:	Catalina Crossosoma
Species Code:	CROCAL
Ecotype:	Catalina Island, California
General Distribution:	Catalina Crossosoma is found throughout southern California and the Channel islands. On Catalina Island, it inhabits chaparral, and oastal sage shrub communities.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Stock Type:	#1 Treepot (173 c ubic inches)
Time To Grow:	9 Months
Target Specifications:	Height: N/A<br> Caliper: N/A<br> Root System: Firm root plug in container.
Propagule Collection:	Seeds are hand collected when they are fully matured. We have collected seeds from December to May. Seeds are shiny black at maturity.
Propagule Processing:	Fruits dry in paper bags in a warm, dry room. We sift rough material through Graimans brand J (10/64ths)pan to break up seeds from the dense arils. We sift witha US Standar #18 sieve and rib material with a rubber blok over a #18 or 20 screen. We place material into a rock tumbler for several hours with grit until most of the remaining arils are removed. We sift with a #18 or #20 sieve and blow at 30 setting to remove fine debris and unfilled seeds. After seeds have been cleaned, they are stored under refrigeration in air tight glass containers at 40 F and 40% RH. With 8 collections, seeds average 0.59 grams per 100 seeds.
Pre-Planting Treatments:	We have used a 5 to 10 minute Physan disinfectant soak or a 3 to minute 5% bleach solution to surface sterilize seed coats prior to testing or sowing. We soak seeds in distilled water for 24 hours. We use a brief 30 minute hot water soak or use Wrights Liquid Smoke at the rate of 1:2 (v:v) liquid smoke to water for 24 hours. Seeds undergo naturl cold, moist stratification during early winter months. Germination percentages have ranged up to 56% using these treatments.
Growing Area Preparation/ Annual Practices for Perennial Crops:	The James H. Ackerman Native Plant Nursery is located on Catalina Island off the coast of southern California. From 1993 to 2004, the average maximum and minimum temperatures have been 75.4 F and 46 F, with an average of 361 frost free days per year and annual rainfall of 14 inches. The facility is comprised of shade houses, mist propagation house, and an outdoor growing area. All propagation environments are utilized at different stages of seedling growth to provide for the variance in temperature and shading requirements needed during the growing season. We irrigate all containers with an overhead emitter system in the shadehouses and use a drip system or hand water in the outdoor nursery.
Establishment Phase:	Seeds are sown in late fall and germinate in early spring in a shadehouse were they remain for several weeks. Seeds are directly sown into flats filled with a 1 inch layer of special seed germination mix of 1:1 (v:v) Sunshine Professional Growing Mix and sand on top of 4:1:1 (v:v:v) peat, perlite, and organic compost. We incorporate Osmocote time release fertilizer (9 month release rate) (14 N:14P2O5:14K2O) at the rate of « cup per 0.75 cubic yard of medium. Seeded flats are watered with an overhead emitter system as needed.
Length of Establishment Phase:	1 to 2 months
Active Growth Phase:	After seedlings are well established and have at least 2 true leaves, they are transplanted into Deepots (40 cubic inch) containers filled with a growing medium of 4:1:1 (v:v:v) peat, perlite, and organic compost. Osmocote time release fertilizer (9 mo release rate) (14 N:14P2O5:14K2O) is incorporated into the medium at a rate of of « cup per .75 cubic yards of medium. Following transplanting, seedlings are moved to another shadehouse with more temperature variance where they remain for several weeks. We shift Deepots into treepotsas needed.
Length of Active Growth Phase:	7 months
Hardening Phase:	Any nursery stock grown under shadehouse conditions are hardened by placing them in full sun exposure for a minimum of 2 weeks prior to outplanting.
Length of Hardening Phase:	2 to 4 weeks
Harvesting, Storage and Shipping:	Containerized seedlings are over wintered directly in the open growing area.
Length of Storage:	Variable; depends on out planting date.

Citation:

Herrera, Mike; Takara, Janet. 2006. Propagation protocol for production of Container (plug) Crossosoma californicum Nutt. plants #1 Treepot (173 c ubic inches); Catalina Island Conservancy Avalon, California. 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.