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Helianthus (divaricatus)

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: Asteraceae
Family Common Name: (Asteraceae)
Scientific Name: Helianthus divaricatus
Common Name: Woodland sunflower
Species Code: HELDIV
Ecotype: Shenandoah National Park
General Distribution: Maine to Florida, west to Nebraska and Louisiana. Found in dry woodlands.
Propagation Goal: seeds
Propagation Method: seed
ProductType: Container (plug)
Time To Grow: 0
Target Specifications: Stock Type: Container plug. Height: 4-6". Root System: Firm full plug; roots fill container.
Propagule Collection: Collected at Shenandoah National Park, Skyline Drive, mileposts 7.1, 102-105, 106 (Signal Knob on left) by J. Englert on 8/21/92 and 9/21/92; by G/D Meyer on 8/25/94.
Propagule Processing: Seed Processing: Seed was harvested from the National Plant Materials Center production fields from late August through November by combine. Gold finches and other birds loved the seed and would often strip the field before it could be harvested. Problems were encountered with the combine which chopped chaff to same size and weight as seed and resulted in difficulty separating seed for cleaning. Seed was cleaned with large clipper, screens 6, 8, and small clipper, 1/15, blank.
Seeds/Kg: 230,000.
Germination: Untested.
Purity: Extremely variable from 12-57%. See seed processing.
Pre-Planting Treatments: Seed Treatments: Seeded trays were given 3-4 weeks cool moist stratification in seed cooler.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Propagation Environment: Greenhouse with alternating day/night temperatures; daytime temperatures vary from 70-85§F depending on natural solar; night temperatures average around 65-68§F. Plugs were grown under 14-16 hour long day conditions using high pressure sodium lighting from 4:30-10:30 p.m.

Seed Propagation Method: Seeds are hand-sown in plug propagation trays.

Container Type and Volume: Started in 392 germination plug trays; transplanted to Ropak Multipots or 72 plug trays.

Growing Media: Seed is sown into germination mix. Seedlings are transplanted into Sunshine #1 or #5 potting mix, amended with 18-6-8,180-day Nutricote SR at 0.15 lb./cu. ft., or 20 oz. per 3.8 cu. ft. bale of potting media.
Establishment Phase: Sowing Date: December.

% Emergence and Date: In 1997, 7-12 days with uncovered trays hand misted. This seed has had poor germination so trays were heavily seeded and no gram weight was recorded.

Sowing/Planting Technique: Seeds are hand sown into germination mix. Flats are given a fungicidal drench, covered with plastic, stratified for 4 weeks and, after returning to the bench, kept evenly moist until well-germinated.

Establishment Phase: Transplanted from germination trays to Ropak multipots at 3-4 weeks post germination.
Active Growth Phase: Rapid Growth Phase: Provided even moisture, treated for usual greenhouse pests as needed and fertilized lightly approximately bi-weekly or as needed with soluble fertilizer at 100 ppm N. Foliar cutback at approximately 6 weeks, or as needed.
Hardening Phase: Hardening Phase: Plugs are hardened off by cooling greenhouse down or placing plug trays outdoors, weather permitting approximately 2 weeks prior to outplanting and discontinuing fertilizer at this time.
Harvesting, Storage and Shipping: Total Time to Harvest: Approximately 12 weeks from germination to finished plug.

Storage Conditions: Plugs not overwintered.
References: Gleason, H. A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada, 2nd edition. New York Botanical Garden.


Davis, Kathy M.; Kujawski, Jennifer. 2002. Propagation protocol for production of Container (plug) Helianthus divaricatus seeds 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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