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Protocol Information

John M. Englert
Natural Resources Conservation Service - Norman A. Berg National Plant Materials Center
Bldg. 509, BARC - East, E. Beaver Dam Road
Beltsville, Maryland 20705
(301) 504-8175
(301) 504-8741

Family Scientific Name: Betulaceae
Family Common Name: Beech Family
Scientific Name: Betula nigra
Common Name: River birch
Species Code: BETNIG
Ecotype: National Capital Parks-East, Washington, DC, and George Washington Memorial Parkway.
General Distribution: River birch’s range is from New Hampshire to Florida and west to southern Ohio, southern Michigan, southeastern Minnesota, eastern Kansas, and Texas. It grows in swamps, along river banks, and in flood-plain forests.
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Container (plug)
Stock Type: 1 to 2 gallon containers
Time To Grow: 18 Months
Target Specifications: Height: 24-60 inches.
Caliper: information not available.
Root System: roots fill container, full root ball when pulled from container.
Propagule Collection: Collected in National Capital Parks-East, Washington DC; Oxon Run Parkway by J. Kujawski on 5/19/97 and 5/14/98; George Washington Memorial Parkway, Virginia by J. Kujawski on 5/23/97 and 5/19/98.
Propagule Processing: Seed Processing: Minimal processing is required for river birch seed cleaning. We put seeds in paper bags and allowed the strobiles to fall apart into individual seeds over a period of 3-4 days.
Seed storage: Seeds do not appear to store well; germination tests with seed 1 yr old or older yielded 0% germination.
Seeds/Kg: Approximately 1,000,000.
Germination: 1997 seed from Oxon Run and George Washington Parkway surface sown on soilless mix had less than 1% germination, while 1998 Oxon Run seed sown on blotter paper and set under automatic mist had 60% germination. Working with seed that was not fresh yielded no germination with either sowing method.
Purity: Ranged from 68% in 1997 to 99% in 1998. Oxon Run seed had higher purity than George Washington seed.
Pre-Planting Treatments: Seed Treatments: According to USDA Handbook 450, stratification improves germination, but is not necessary if seeds are exposed to light during germination. Since we surface sowed all seed, we did not provide any pre-germination treatment.
Growing Area Preparation/
Annual Practices for Perennial Crops:

Propagation Environment: Greenhouse with fluctuating day/night temperatures as determined by solar radiation (no supplemental heat) and natural daylength/
Seed Propagation Method: Seeds hand sown on surface of soilless mix or sown in a single layer on blotter paper.
Container Type and Volume: Seeds are started on either open trays or on sheets of blotter paper. After they germinate, the seedlings are transferred through a series of containers, from 72-cell plug trays to quarts to half-gallon and gallon containers.
Growing Media: Seeds are started on either a mix of 1:1 Sunshine #1: perlite or on desk blotter paper; seedlings are transferred into Sunshine #1 plus 180 day Nutricote SR 18-6-8 @ 20 oz. per batch or 0.15 lb. per cu. ft. mix. Larger container plants are potted in a woody mix (3.8 cu ft. bale Sunshine #1, 4 cu. ft. of pine bark mulch, 20 oz. Nutricote and approximately 20 oz. ecto-mycorrhizae).
Establishment Phase: Sowing Date: Seeds are sown after collection, in late May or early June. Winter seeding has not been successful for us.
Emergence and Date: Most seedlings appeared over a 2-week period following sowing.
Sowing/Planting Technique: Seeds are spread in a thin layer over the medium surface or blotter paper. Seeds on trays of medium are maintained on a greenhouse bench with hand-watering; seeds on blotter paper are placed under an 24-hour automatic misting system set at approximately 10 seconds every 30 minutes.
Establishment Phase: Seedlings are removed from blotter paper immediately after germination and planted in 72-cell plug trays. Those on soilless mix are allowed to continue growing in the trays. They are ready to transplant to quarts by the end of the summer.
Active Growth Phase: Rapid Growth Phase: Seedlings put on growth during June, July, and August.
Hardening Phase: Hardening Phase: Plants require a chilling period, even the first year. Plants in the greenhouse in quart containers did not develop normally when left in the greenhouse over the first winter. Plants in quart containers are placed outside and allowed to acclimate to cooler conditions through the fall; over the winter they are stored in a cold, protected location from late November until March.
Harvesting, Storage and Shipping: Harvest Date: Container materials reach 1/2 gallon to 1 gallon size in 2 years, at which point they are moved to the Park for planting. Some materials reach 2 gallon size in 3 growing seasons.
Total Time to Harvest: It takes 2-3 growing seasons to get a 1-2 gallon container plant. Generally, most plants are in the 24-48 inch range in 1 gallon pots.
Storage Conditions: Quart containers are stored in NPMC cold storage @ 40º F, 35% relative humidity. Larger container plants are over-wintered outdoors under microfoam.
Outplanting performance on typical sites: Outplanting Site: National Capital Parks-East, George Washington Memorial Parkway.
Outplanting Date: Spring.
Other Comments: We have had wildly fluctuating results with this species, and seen differences in the quality of seed between collection sites. Germination on blotter paper is a useful technique and avoids wasting planting mix for poorly germinating species.
References: Gleason, H and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. 2nd edition. New York Bot. Garden.

Kujawski, J. 1997, 1998. Annual Report to the National Park Service for National Capital Parks-East, Oxon Run Parkway. USDA NRCS National Plant Materials Center. Beltsville, MD.

Kujawski, J. 1997, 1998. Annual Report to the National Park Service for George Washington Memorial Parkway. USDA NRCS National Plant Materials Center. Beltsville, MD.

Davis, Kathy M.; Kujawski, Jennifer L. 2001. Propagation protocol for production of container Betula nigra plants (1 to 2 gallon containers); Natural Resources Conservation Service - Norman A. Berg National Plant Materials Center, Beltsville, Maryland. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 31 August 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.