Untitled Page
About Us
Propagation Protocol Database
Subscribe to Native Plant Journal
Print View

Protocol Information

Native Plant Nursery
USDI NPS - Glacier National Park
West Glacier, Montana 59936
(406) 888-7835

Family Scientific Name: APIACEAE
Family Common Name: Carrot Family
Scientific Name: Heracleum maximum Bartr.
Common Synonym: Heracleum lanatum Michx.
Common Name: Cow Parsnip
Species Code: HERMAX
Ecotype: Streambank adjacent to Cedar forest, Avalanche,Glacier National Park, Flathead County, MT. 1030 meters
General Distribution: H. maximum is found throughout North America. It occurs along streambanks and in moist ground from lowland coniferous forests to the subalpine zone.
Propagation Goal: Plants
Propagation Method: Seed
Product Type: Container (plug)
Stock Type: 172 ml conetainers
Time To Grow: 18 Months
Target Specifications: Height: 6 cm, 4 to 6 true leaves
Caliper: n/a
Root System: firm plug in conetainer
Propagule Collection: Seeds are hand collected when the schizocarps turn tan in late August. Paper bags are used for collection and seeds are kept in well ventilated drying shed prior to cleaning.
Collection Locality: Logan Pass
Propagule Processing: Seeds are cleaned using an air blower and screens. Seed longevity estimated at 3 years in sealed containers at 1C. Seed dormancy is classified as nondeep morphological-physiological dormancy. % Purity: 100% % Germination: 89%
Pre-Planting Treatments: 72 hour water soak of fresh seeds. Water was changed daily. Seeds were placed into a 100 day cold, moist stratification. Seeds were placed in fine mesh bags and buried in moist peat moss in a ventilated container under refrigeration at 1 to 3C. The running water presoak treatment is necessary for adequate germination. Calcium oxalate and other inhibitors are present in the seed coats and must be leached out.
Growing Area Preparation/
Annual Practices for Perennial Crops:

Greenhouse and outdoor nursery growing facility.
Sowing Method: Direct Seeding. Seeds are sown by hand and lightly covered with medium.
Growing medium used is 50% milled sphagnum peat, perlite, and vermiculite with Osmocote controlled release fertilizer (13N:13P2O5:13K2O; 8 to 9 month release rate at 21C) and Micromax fertilizer (12%S, 0.1%B, 0.5%Cu, 12%Fe, 2.5%Mn, 0.05%Mo, 1%Zn) at the rate of 1 gram of Osmocote and 0.20 gram of Micromax per 172 ml conetainer.
Establishment Phase: Seeds did not germinate the 1st year, conetainers were placed in the outdoor nursery for the remainder of the growing season and were winterized outdoors. Initial germination the following spring appeared uniform and occurred following several days of temperatures at 22C or above during the day and 13C to 16C at night in early June in the outdoor nursery. Conetainers are misted twice per day during the establishment phase.
Length of Establishment Phase: 4 weeks
Active Growth Phase: Root and shoot development occurs rapidly following germination. 4 to 6 true leaves were evident 3 weeks after germination. Plants were fertilized with 20-20-20 NPK liquid fertilizer at 100 ppm during the growing season. Seedlings are irrigated with Rainbird automatic irrigation system in early morning until containers are thoroughly leached. Leaves are large and irrigation becomes difficult in conetainers; it is necessary to uppot to 3 L (1 gallon) containers if stock is to be held overwinter.
Length of Active Growth Phase: 8 weeks
Hardening Phase: Irrigation is gradually reduced in September and October. Plants are flushed with clear water and fertilized with 10-20-20 NPK liquid fertilizer at 200 ppm once before winterization.
Length of Hardening Phase: 4 weeks
Harvesting, Storage and Shipping: Total Time to Harvest:1.5 years
Harvest Date: August
Storage Conditions: Overwinter in outdoor nursery under insulating foam cover and snow.
Length of Storage: 5 months
Outplanting performance on typical sites: Outplanting Site:Logan Pass, Glacier National Park, MT. Outplanting Date: early September.
Outplanting Survival at 3 Years: 100%
Other Comments: Following germinationthe second year,seelings can be potted into 3L (1 gallon) containers and will reach root tightness in 3 months.
References: References: Flora of the Pacific Northwest, Hitchcock and Cronquist, 7th edition, University of Washington Press, 1973.

Seeding Rate Statistics for Native and Introduced Species, Hassell, Wendel, U.S.D.I. and U.S.D.A., April 1996.

Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination, Baskin and Baskin, Academic Press, 1998.

Seed Germination Theory and Practice, Deno, Norman, Penn State University, 1993.

Growing Colorado Plants From Seed: A State of the Art. Vol. 3: Forbs, U.S.D.I. NTIS, 1982.

Glacier National Park Native Plant Nursery Propagation Records, unpublished.

Luna, Tara; Evans, Jeff.; Hosokawa, Joy. 2008. Propagation protocol for production of container Heracleum maximum Bartr. plants (172 ml conetainers); USDI NPS - Glacier National Park, West Glacier, Montana. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 2 September 2015). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery.