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Juglans (nigra)

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)

Family Scientific Name: Juglandaceae
Family Common Name: Walnut Family
Scientific Name: Juglans nigra
Common Name: Black walnut
Species Code: JUGNIG
Ecotype: Cumberland Gap National Historical Park, Shenandoah National Park, George Washington Memorial Parkway
General Distribution: New England to Michigan, Minnesota, Nebraska, south to Florida and Texas. Found in rich soil, woods or open fields.
Propagation Goal: plants
Propagation Method: seed
ProductType: Plug + (container-field grown hybrids)
Time To Grow: 0
Target Specifications: Stock Type: Bareroot and container (1 and 2 gallon) material. Height: 24-48". Root System: Container plants have substantial root ball, but root system doesn't always fill container.
Propagule Collection: Collected at Cumberland Gap National Historical Park, VA, TN, KY by J. Englert on October 4, 1996, by J. Copeland on November 18, 1998; Shenandoah National Park, VA by J. Englert on October 5, 1993; George Washington Memorial Parkway, VA by J. Kujawski and J. Key on October 9, 1996 and September 21, 2000.
Propagule Processing: Seed Processing: Seeds are collected into plastic bags to keep husks soft and moist. Husks are cleaned from seeds using a Dybvig separator.
Seeds/Kg: 70.
Germination: Approximately 10%.
Purity: Cleaned seeds are float tested, and purity over the past few years has been over 90%.
Pre-Planting Treatments: Seed Treatments: Seeds are sown outdoors in the fall and undergo natural stratification.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Propagation Environment: Outdoor nursery beds.

Seed Propagation Method: Hand-sowing seed in rows.

Container Type and Volume: Some bareroot materials are harvested and containerized in 1 gallon pots and larger.

Growing Media: Container material is grown in woody mix (3.8 cu ft. bale Sunshine #1, 4 cu. ft. of pine bark mulch, 20 oz. Nutricote and approximately 20 oz. endo-mycorrhizae).
Establishment Phase: Sowing Date: October/November.

% Emergence and Date: Seedlings emerge the following spring after fall sowing.

Sowing/Planting Technique: Seeds are dusted with fungicide and hand sown into rows (rows are 5 to 6 inches apart, seeds are sown side by side with no space in between seeds). Endomycorrhizae are sprinkled over the seed before covering with 1 to 2 inches of soil. The beds are then mulched with aged sawdust. Screening against rodents may be necessary.

Establishment Phase: Sawdust mulch is scraped back in spring prior to seedling emergence. Newly emerged seedlings are monitored closely for irrigation needs.
Active Growth Phase: Rapid Growth Phase: Because National Plant Materials Center soil is a nutrient poor sandy loam, seedlings are fertilized from mid-April with a granular 10-10-10 once a week through early June. From mid-June through late July, the 10-10-10 is alternated with a granular urea every other week. From late July through late August the seedlings are fertilized with 10-10-10 every two weeks. Overhead irrigation is used after every fertilization. The rate of water applied is determined by soil moisture prior to irrigation.
Hardening Phase: HardeningPhase: During mid- to late summer, fertilization is cut back to twice monthly. Beginning in September, irrigation is only used in a severe droughty situation.
Harvesting, Storage and Shipping: Total Time to Harvest: Bareroot plants are harvested 1 year after seeds are sown. Container plants take 1 to 2 seasons beyond bareroot, depending on size of plants needed.

Harvest Date: Dormant bareroot plants are harvested in early to mid-December.

Storage Conditions: Bareroot plants are bundled into groups of 25 (or whatever is manageable), and long roots are trimmed. Bundles are placed into plastic bins; roots are covered with sawdust. Bins are placed into a cold storage room (40§F) and watered as needed during the winter. Gallon size container plants are stored outside. Containers are laid on their side on weed barrier fabric, and covered with 2 layers of a microfoam insulating blanket. The blanket is secured over plants by threading a rope over the blanket between rebar anchors on either side of a block of plants.
Length of Storage: <b>Storage Duration:</b> December to March.
References: Brown and Brown. 1992. Woody Plants of Maryland. Port City Press, Inc.

Cumberland Gap, Shenandoah, George Washington Park collection records at NPMC. Beltsville, MD.

Gleason, H and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. 2nd edition. New York Bot. Garden.

USDA, Forest Service. 1974. Seeds of Woody Plants in the United States. USDA, Ag. Handbook 450.


Davis, Kathy M.; Kujawski, Jennifer. 2001. Propagation protocol for production of Plug + (container-field grown hybrids) Juglans nigra plants USDA NRCS - Norman A. Berg National Plant Materials Center Beltsville, Maryland. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2021/05/11). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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