RNGR.net is sponsored by the USDA Forest Service and Southern Regional Extension Forestry and is a colloborative effort between these two agencies.

U.S. Department of Agriculture USDA Forest Service Southern Regional Extension Forestry Southern Regional Extension Forestry

Skip to content. | Skip to navigation

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

Robinia (pseudoacacia)

John M. Englert
USDA NRCS - Norman A. Berg National Plant Materials Center
Bldg. 509, BARC - East, E. Beaver Dam Road
Beltsville, Maryland 20705
(301) 504-8175
(301) 504-8741 (fax)
john.englert@wdc.usda.gov
http://plant-materials.nrcs.usda.gov/mdpmc/
Family Scientific Name: Fabaceae
Family Common Name: Bean Family
Scientific Name: Robinia pseudoacacia L.
Common Name: black locust
Species Code: ROBPSE
Ecotype: Cumberland Gap National Historical Park, Shenandoah National Park.
General Distribution: R. pseudoacacia is native from Pennsylvania and south Indiana to Oklahoma, south to Georgia and Alabama. Escaped form cultivation north to Nova Scotia and Quebec (Gleason and Cronquist, 1991).

Note: Black locust is on the native species list for the above national Parks. NRCS recognizes that it can be weedy outside its native range. Please consult the NRCS PLANTS database for more information.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Stock Type: Seedling
Time To Grow: 2 Years
Target Specifications: Half-gallon greenhouse-grown container plants.<br> Container plants should have firm root balls that fill the pot. The insides of containers are treated with Spin Out, a copper hydroxide product that encourages development of a fibrous root system.<br> Height: Half-gallon container seedlings vary from 24 to 60".<br><br>
Propagule Collection: Seeds were collected from the Parks in September and October after it had ripened but before the legumes had split.
Propagule Processing: Cleaning: Seeds are spread out to dry. Dried pods are run through a hammermill to separate out the seed from the chaff.
Storage: Cleaned seed is stored in sealed containers in a cooler at 40F and 30% relative humidity.
Purity: After cleaning, purity was estimated at over 98%.
Germination: untested. Recently, harvest has been between 1% and 2% of all seeds planted. Germination depends on quality of seed and seed lot and if there has been insect damage. It varies by park.
Seeds per Kg: between 55,600 and 89,300( 66,700 average).
Pre-Planting Treatments: Black locust seeds have an impermeable seedcoat (Olson, 1974). Prior to planting, seeds were run through a Fosburg scarifier to scratch the seedcoat and then were inoculated with rhizobia specified for Robinia.
Growing Area Preparation/
Annual Practices for Perennial Crops:		 Seed was sown in the greenhouse in spring.
Container plants: Pre-scarified, inoculated seeds are sown in trays in germination mix. They are transplanted to quarts in a mix of Sunshine #1 and slow release 18-6-8 Nutricote. (3.8 cu ft mix, 4 cups Nutricote). Seedlings are bumped up to « gallon containers with a woody mix: (3.8 cu. ft. media, 4 cu. ft. pine bark mulch, 4 cups Nutricote, about 4 cups endomycorrhizae and rhizobia at recommended rates.
Establishment Phase: Newly emerged seedlings are monitored closely for irrigation needs. Seedlings are not shaded.
Active Growth Phase: Greenhouse seedlings in half-gallon pots are transferred to an outdoor shade house for the growing season. Daily overhead irrigation is adjusted depending on natural precipitation and pot size. Plants may need to be staked. Plants may be top-dressed with slow release fertilizer.
Hardening Phase: Frequency and duration of irrigation is reduced as plants go dormant, depending on natural rainfall.
Harvesting, Storage and Shipping: Smaller pots may be over-wintered in a cooler and watered needed. Dormant « gallon stock is over-wintered outdoors under a microfoam-insulating blanket. After leaves have fallen, the clean, well-watered containers are overlapped on their sides on weed barrier fabric and covered with microfoam. Rodenticide baits are placed at intervals under the blanket to discourage gnawing rodents. The microfoam is then anchored with rope and rebar.
Length of Storage: 3 to 5 months
References: Olson, David F. 1974. Robinia In: Seeds of Woody Plants in the United States. Forest Service, USDA. Agricultural Handbook 450. Washington, DC. 728-731.

Brown, Russell G. and Melvin L. Brown. 1992. Woody Plants of Maryland. Port City Press, Baltimore, MD.
Dirr, Michael A. and Charles W. Heuser, Jr. 1987. The Reference Manual of Woody Plant Propagation. Varsity Press, Inc., Athens GA.

Gleason, Henry A. and Arthur Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. 2nd. Edition. New York Botanical Garden, Bronx, NY.
USDA-NRCS National Plant Materials Center. Woody bed and container nursery plant records. Unpublished.

Citation:

Davis, Kathy; King, Brandy; Kujawski, Jennifer. 2003. Propagation protocol for production of Container (plug) Robinia pseudoacacia L. plants Seedling; USDA NRCS - Norman A. Berg National Plant Materials Center Beltsville, Maryland. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/01). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.