Sphaeralcea (ambigua)

Jean Graham Nursery Manager USDI NPS - Joshua Tree National Park Native Plant Nursery 74485 National Park Drive Twentynine Palms, California 92277 760-367-5565 http://www.ggnpa.org

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Family Scientific Name:	Malvaceae
Family Common Name:	Hibiscus Family
Scientific Name:	Sphaeralcea ambigua Gray
Common Name:	Desert Globe Mallow
Species Code:	SPHAMB
Ecotype:	Joshua Tree National Monument, California
General Distribution:	Sphaeralcea ambigua is found in dry rocky slopes and canyons mostly below 4,000 ft elevation throughout the Californian deserts east to Utah and Arizona. It also ranges south into Lower California.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Stock Type:	2 Gallon PVC container
Time To Grow:	8 Months
Target Specifications:	Height: N/A<br> Caliper: N/A<br> Root System: Firm Root Plug in container
Propagule Collection:	Seeds are hand collected in May when capsules have matured and begin to split open.
Propagule Processing:	Seeds are allowed to dry for 4 to 6 weeks in paper bags in a warm, dry room. After seeds have been cleaned, they are stored under refrigeration in air tight containers at 7C.Inferred seed dormancy is physical dormancy.
Pre-Planting Treatments:	Seeds are hot water scarified by placing seeds into boiling water and immediately removing pan from heat source. Seeds soak in cooled water for 12 to 24 hours. Seeds are placed between sheets of blotter paper in nursery flats and wrapped in plastic bags to prevent desiccation. We transplant viable germinants into containers as soon as the radicle emerges. Flats are checked for new germinants daily. Seeds can also be sown in open flats using a growing medium of 2 parts sand, 1 part mulch and 2 parts perlite (v:v:v). Germination %:11%
Growing Area Preparation/ Annual Practices for Perennial Crops:	The Joshua Tree Native Plant Nursery is located in the Mojave Desert of southern California and has an average of 250 frost free days per year and annual rainfall of 5 to 10 cm (2 to 4 in.) The facility is comprised of two greenhouses, shade structures, mist propagation beds and an outdoor growing compound. All propagation environments are utilized at different stages of seedling growth to provide for the variance in temperature and shading requirements during the growing season. We irrigate all containers with an automated drip irrigation system.
Establishment Phase:	Seedlings are germinated during winter months in a small greenhouse were they remain for 4 weeks. Flats and containers are watered with a drip irrigation system. After seedlings are well established and have at least 2 true leaves, they are transplanted into newspaper cylinders wrapped with polyvinyl food wrap. The newspaper container is 29 cm (11.5 in) tall and 7.5 cm (3 in) in diameter. The newspaper pots are filled with a growing medium of 2:1:1 (v:v:v) sand, mulch, and perlite.
Length of Establishment Phase:	4 weeks
Active Growth Phase:	Seedlings are ready for transplanting into larger containers at 8 to 12 weeks. The entire newspaper pot minus the plastic wrap is transplanted into the PVC tall containers using the same medium described for the newspaper containers. Osmocote time release fertilizer (9 mo release rate) (13 N:13P2O5:13K2O) is incorporated into the medium at the approximate rate of 22 g per 6l ( 2 gal) PVC containers. PVC containers are 37.5 cm tall(15 in) and are 15 cm (6 in)in diameter. Following transplanting, seedlings are moved to a larger greenhouse with more temperature variance where they remain for another 4 weeks. Approximately 4 weeks old after transplanting, they are moved to the open growing compound that is covered with a 55% shadecloth during the summer months. During the months of intense summer heat, containers are irrigated by an automated drip system every other day with occasional deep irrigation to leach out accumulated salts.
Length of Active Growth Phase:	5 months
Hardening Phase:	Irrigation frequency and duration is gradually reduced for 4 to 8 weeks prior to out-planting. The shadecloth is removed from the open growing compound in October when daytime temperatures begin to cool. Nursery stock is top pruned at this stage.
Length of Hardening Phase:	2 months
Harvesting, Storage and Shipping:	Containerized seedlings are over wintered directly in the open growing compound.
Length of Storage:	Variable; depends on out planting date.

Citation:

Graham, Jean. 2003. Propagation protocol for production of Container (plug) Sphaeralcea ambigua Gray plants 2 Gallon PVC container; USDI NPS - Joshua Tree National Park Native Plant Nursery Twentynine Palms, California. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/05/18). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.