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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

Parkinsonia (floridum)

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
Family Scientific Name: Fabaceae
Family Common Name: Pea Family
Scientific Name: Parkinsonia floridum (Benth ex Gray) Wats.
Common Synonym: Cercidium floridum Benth ex Gray
Common Name: Palo Verde
Species Code: PARFLO
Ecotype: Joshua Tree National Monument, California
General Distribution: Parkinsonia florida is foundin washes and sandy places below 12oo ft elevation in the Colorado desert of Arizona and southern California. it is also found into Lower California and Sonora, Mexico.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 2 Gallon PVC Pipe container
Time To Grow: 12 Months
Target Specifications: Height: N/A<br> Caliper: N/A<br> Root System: Firm Root Plug in container.
Propagule Collection: Seeds are colected in summer whem pods 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 scarified by clipping and soaking in water overnight.
Seeds can be directly sown to containers.
Seeds can also be 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 are sown in open flats using a growing medium of 2 parts sand, 1 part mulch and 2 parts perlite (v:v:v).
Germination %: 100%
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.
monitor for top and root pruning.
Length of Active Growth Phase: 9 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) Parkinsonia floridum (Benth ex Gray) Wats. plants 2 Gallon PVC Pipe container; USDI NPS - Joshua Tree National Park Native Plant Nursery Twentynine Palms, California. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/02/25). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.