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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

Juglans (nigra)

Gregory Hoss
Nursery Manager
George O. White State Forest Nursery
PO Box 119
Licking, Missouri 65542-0119
573-674-3229
GIF-native-plants@prodigy.net

Family Scientific Name: Juglandaceae
Family Common Name: Walnut Family
Scientific Name: Juglans nigra L.
Common Name: Black walnut
Species Code: JUGNIG
Ecotype: South Central Missouri
General Distribution: Black walnut is found throughout the eastern United States. It grows as far north as southern Minnesota, southern Wisconsin, southern Michigan, and southern Ontario. Isolated populations occur in the southern half of New York, Vermont, western Massachusetts, and northwestern Connecticut. Its range extends south to northwestern Florida, and to Mississippi, Arkansas, and Louisiana except for the Mississippi Valley and Delta regions. Isolated populations occur in eastern Texas, western Oklahoma, central Kansas, Nebraska, and southeastern South Dakota. It inhabits mesic soils and well drained upland sites, in a variety of mixed hardwood deciduous and coniferous forests from sea level to 1,000 m (0 to 3,280 ft) elevation. Our seed sources are from south central Missouri.
Propagation Goal: plants
Propagation Method: seed
ProductType: Bareroot (field grown)
Stock Type: 1+0
Time To Grow: 1 Years
Target Specifications: 24 to 30 in tall<br> 0.25 to .50 in caliper<br> Root system must balance top growth.<br>
Propagule Collection: Seeds are purchased from local people who collect within a 50 mile radius of the nursery.Nuts are during fall months and are kept separated according to site, elevation and source or cultivated variety.
Propagule Processing: Large quantities can be cleaned with mechanical hullers. After cleaning, nuts can be placed into water flotation, which keeps the nuts hydrated and facilitates the removal of non-viable nuts which will float, trash and other debris.We use a Jesse aspirator which uses suction, gravity and vibration to separate viable from non-viable seeds. De-hulling is not necessary for improved rates of germination, but is practical for cooler storage of spring sown seeds.There are 25 to 220 seeds per kilogram (11 to 100 seeds per pound) Bonner 2004).Walnuts have sub-orthodox seeds, meaning that they are viable for 1 year. Black walnut can be successfully stored for 1 year in plastic bags at 2 to 3ø C (37ø F) with a seed moisture content of 20 to 40 percent.
Pre-Planting Treatments: Seeds are fall sown with a mechanical seeder or by hand in prepared field beds. We sow nuts up 3 to 4 in deep to protect thme from deer, rodents and birds.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Soils: Our field soils are silty clay loams.
The spring before planting, we amend the soils with 700 lbs/acre of 1N:3 P205:5K20, grow a soybean cover crop, and fumigate in the fall. We use Roundup Ready soybeans so we can control weeds by using glycosate herbicide without harming the cover crop. During early August, we disk under the cover crop and disk the soils several times during the next 6 weeks to obtain a smooth soil surface. Soils are fumigated in late September.
Field Bed Preparation: We mark out and form beds as needed. Beds are prepared with a rototiller/seedbed former and are typically 4 to 6 inches high and 4 ft wide. Fields are cultivated for weeds as needed throughout the growing season.
Irrigation: We use overhead irrigation with two inch pvc pipe that can be moved from field to field each year. Our principle water source is from 3 on-site wells and is very good quality water.
Establishment Phase: Seeds are covered and irrigated when soils appear to be drying out on warm days. We apply old sawdust and hydromulch after sowing.
Length of Establishment Phase: 1 month after emergence in the spring
Active Growth Phase: Year 1: Fertilization: We apply ammonium sulfate 21-0-0-24 with a mechanical spreader. We put on the first application the last week of May and to only those 1+0 seedlings that have been germinated for at least 5 or 6 weeks. We put down our last application during the last week of July. Because black walnut grows rapidly, we only apply fertlizer once during the growing season. We apply fertilizer at the rate of 125 lbs/acre. We irrigate for at least 45 minutes following all fertilizer applications. This insures that foliage will not burn and incorporates fertilizer into the root zone.
ROOT PRUNING PROCEDURES:Pruning depth is at least 10 inches for 1+ 0 stock.
Irrigate heavily for 2 to 3 days prior to pruning to saturate the root zone. Set pruning blade to slightly wrench seedlings as they are pruned. Check pruning depth frequently and adjust as needed. Irrigate for a minimum of 2 hours following root pruning to settle soil back around roots. This step is critical to eliminate post root pruning mortality. Irrigate field heavily for 2 to 3 days to further settle the soil.
TOP PRUNING PROCEDURES: We top prune only to keep nursery stock from becoming damaged by the mechanical lifter. Our clients prefer stock that has not been severely shoot pruned.
Length of Active Growth Phase: 4 months
Hardening Phase: Hardening begins during Septemebr or when dormancy is induced. Irrigation frequency and duration is shortened and applied only when needed.
Length of Hardening Phase: 3 months
Harvesting, Storage and Shipping: Lifting window is from late November to April, depending on species. We try to obtain a large a root mass as possible. Seedlings are hand lifted after the seedling beds have been undercut at an average depth of 10 or 12 inches using a lifter. Lifted nursery stock is immediately stored in cooler until graded and bundled. The majority of species are graded, bundled and shipped during February.
Length of Storage: 3 to 4 months
References: Bonner FT. 2004. The genus Juglans. In: Woody Plant Seed Manual (on-line version) URL: http://wpsm.net/Juglans.pdf

Citation:

Hoss, Gregory. 2005. Propagation protocol for production of Bareroot (field grown) Juglans nigra L. plants 1+0; George O. White State Forest Nursery Licking, Missouri. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/02). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.