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Ilex (verticillata)

Martin van der Grinten
USDA NRCS - Big Flats Plant Materials Center
RD #1, Route 352, Box 360A
Corning, New York 14830-0360
(607) 562-8404
(607) 562-8516 (fax)

Family Scientific Name: Aquifoliaceae
Family Common Name: Holly
Scientific Name: Ilex verticillata (L.) Gray
Common Name: Winterberry
Species Code: ILVE
Ecotype: Mt. Desert Island, Maine
General Distribution: Winterberry ranges from Newfoundland to Minnesota and south to Florida. Found in swamps, bogs and on shores of streams, ponds and lakes.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Time To Grow: 0
Target Specifications: Stock Type: 1 gallon container seedlings. Height: 8 inches. Root System: Plants have a good root system in containers.
Propagule Collection: Collected in Acadia National Park, Maine by Martin van der Grinten in October by hand harvest.
Propagule Processing: Seed Processing: After the berries are picked, they can be run through a dibuig or a kitchen blender for 30 seconds to remove the pulp and then laid on a fine screen to dry. Clean the seed by using the Clipper (Midget II model) seed cleaner, with a 8/64 round top screen, blank bottom screen and air 30% open.
Seeds/Kg: Varies - approximately 92,000 seeds per pound.
Pre-Planting Treatments: Seed Treatments: This seed has a deep dormancy. Germination will be delayed to the second spring after sowing the seed.
Growing Area Preparation/
Annual Practices for Perennial Crops:
Propagation Environment: Seed is placed in cold frames till germination. After germination, they are potted and placed in greenhouse. When the
plants have sufficient growth, they are transplanted to lathe house.

Seed Propagation Method: Seed should be sown in the fall in flats placed in cold frames. Due to deep dormancy, the seed will germinate in the 2nd year.

Container Type and Volume: 1 gallon container.

Growing Media: Pro-Mix BX media.
Establishment Phase: Sowing Date: Seed should be sown in late fall/early winter, to utilize the natural stratification.

% Emergence and Date: Good germination should occur in 2nd spring.

Sowing/Planting Technique: Sow seed in sturdy plastic flats with Metro-Mix 360 and coverwith 1/3 to 1/2 inches of Metro-Mix. Place in a cold frame
in late fall.

Establishment Phase: Once seedling has germinated, transplant to 5 inch pots with Metro-Mix 250. Monitor watering. Germination will occur in the 2nd year.
Active Growth Phase: Rapid Growth Phase: When the seedlings are of sufficient size, transplant into 1 gallon containers, using Pro-Mix BX potting media. Fertilize with
Osmocote slow release fertilizer. Monitor watering.
Hardening Phase: Hardening Phase: Once seedlings are transplanted into five inch pots, they can be placed in lathe house for continued growth.
Harvesting, Storage and Shipping: Total Time To Harvest: It takes 3 to 4 years to get a seedling to a 1 gallon size plant.

Harvest Date: October.

Storage Conditions:Store seed at 40øF in seed cooler.
Other Comments: Vegetative Propagation Method: Refer to "The Reference Manual of Woody Plant Propagation" by Dirr and Heuser, Varsity Press Inc., 1987.
References: Trees and Shrubs of New England, M. D. Dwelley, Down East Books, 1980.

Seeds of Woody Plants of North America, Young and Young, Dioscorides Press, 1992.


Van Der Grinten, Martin. 2001. Propagation protocol for production of Container (plug) Ilex verticillata (L.) Gray plants USDA NRCS - Big Flats Plant Materials Center Corning, New York. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2020/08/05). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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