Oxydendrum (arboreum)

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/

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Family Scientific Name:	Ericaceae
Family Common Name:	Heath Family
Scientific Name:	Oxydendrum arboreum
Common Name:	Sourwood
Species Code:	OXYARB
Ecotype:	Great Smoky Mountains National Park, Cumberland Gap National Historical Park
General Distribution:	Pennsylvania to Indiana, south to Florida and Louisiana. Commonly found in woods of mountainous areas.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Plug + (container-field grown hybrids)
Time To Grow:	0
Target Specifications:	Stock Type: Because the seed is so small, Oxydendrum seedlings are started in the National Plant Materials Center greenhouses and are transplanted as plugs (usually at the 4-5 month stage) out to the NPMC woody beds. There, they are grown under shade for two years and are dormant-harvested during late fall or early winter as 6-12" seedlings. They are over-wintered bare root in moist sawdust in the National Plant Materials Center cooler. In spring, bare root stock is delivered to the park for outplanting or potted into containers and grown as specimens for high visibility areas (i.e. parking lots) in the park. Specimen plants are finished in our shade house as 2-3 gallon containers (48-72" height.) Height: Plug: 4-6"; bare root: 6-12"; container specimen: 60-72". Root System: Full in container, but not pot-bound. The bare root plants harvested from the National Plant Materials Center woody beds in fall, 2000, had dense, fibrous root balls that resembled the root systems found in container pla
Propagule Collection:	Collected at Hensley Settlement in Cumberland Gap National Historical Park by J. Copeland on 11/91, 10/21/96 and 10/20/97; Great Smoky Mountains National Park, Foothills Parkway, West, Wears Valley and Chilhowee west, by National Park Service staff on 9/94 and 11/95.
Propagule Processing:	Seed Processing: By hand, beaten, rubbed in bag. Seeds/Kg: Unknown. Estimated at over 5 million. Germination: Untested. Purity: Estimated at 50%.
Pre-Planting Treatments:	Seed Treatments: None needed.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Propagation Environment: Greenhouse with alternating day/night temperatures. Trays were placed under continuous fluorescent light and mist (4-second duration at 15 min intervals) during germination. After germination seedlings were given extended 14 hour days under high intensity lights from 4:30-10:30 p.m. Seed Propagation Method: Seed was surface-sown by hand. Container Type and Volume: Seed is sown in 4x4" or 10x20" germination trays. Seedlings are transplanted to 2" pots or 72 plug trays for outplanting to the National Plant Materials Center woody beds. Container specimens are finished in 3 gallon pots. Growing Media: Seeds are sown onto screened peat, peat and perlite or a peat:sand mixture. Seedlings are transplanted into a 1:1 mix of Sunshine #1 and peat.
Establishment Phase:	Sowing Date: Seed is best sown in the greenhouse in January. Plugs from a March, 1999 sowing did not mature in time for field planting that summer. % Emergence and Date: Germination occurred in about 3-4 weeks and seedlings were too numerous to count. Sowing/Planting Technique: Seed was mixed with talc and surface-sown on moist peat in germination trays. (See Propagation Environment under Growing Area/Preparation for details on lighting and misting.) Establishment Phase: Seedlings were transplanted (some in clumps) from germination trays to 2" pots or plug trays at the two-leaf stage in late March, early April. Soil was kept evenly moist, but not saturated and seedlings were fertilized infrequently (about every two weeks) with a dilute solution of Peters Acidic liquid fertilizer. Seedlings in clumps will need to be thinned to allow one dominant plant per cell.
Active Growth Phase:	Rapid Growth Phase: Greenhouse plugs grow slowly during February and March but increase growth with lengthening days. Fertilize as needed with Peters Acidic soluble fertilizer.Hardening Phase: Greenhouse plugs are hardened by putting them outdoors in a sheltered, shaded location for approximately 2 weeks before outplanting in the woody beds.
Hardening Phase:	Hardening Phase: Greenhouse plugs are hardened by putting them outdoors in a sheltered, shaded location for approximately 2 weeks before outplanting in the woody beds.
Harvesting, Storage and Shipping:	Total Time to Harvest: From sowing to 2" plug takes approximately 4 « to 5 months in the greenhouse. The plugs are lined out in the woody beds and are dormant harvested as bare root stock in late fall of their second year. Container specimens spend an additional 2-3 years in the shade house reaching finished size. Harvest Date: Late fall, early winter for bare root plantings in the National Plant Materials Center woody beds. Outplanting in the parks is in the spring. (March for Cumberlant Gap National Historical Park, April or May for Great Smoky Mountains National Park). Storage Conditions: Bare root Oxydendrum that are harvested dormant from the National Plant Materials Center woody beds in the fall are bundled, packed in moist sawdust and overwintered in cold storage (40§F, 35% relative humidity). Container plants in the National Plant Materials Center shade house are overwintered under microfoam. Seed storage: In cooler @ 40§F, 35% relative humidity. Seed dormancy: None.
Length of Storage:	<b>Storage Duration:</b> 3-4 months.
Other Comments:	Vegetation Propagation Method: All National Plant Materials Centers production is from seed.
References:	Brown and Brown. 1992. Woody Plants of Maryland. Port City Press, Inc. Gleason and Cronquist. 1963. Manual of Vascular Plants, D. Van Nostrand Co.

Citation:

Davis, Kathy M.; Kujawski, Jennifer. 2001. Propagation protocol for production of Plug + (container-field grown hybrids) Oxydendrum arboreum plants USDA NRCS - Norman A. Berg National Plant Materials Center Beltsville, Maryland. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/04/23). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.