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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

Pycnanthemum (muticum)

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/
Family Scientific Name: Lamiaceae
Family Common Name: Mint Family
Scientific Name: Pycnanthemum muticum (Michx) Pers.
Common Name: Mountain mint
Species Code: PYCMUT
Ecotype: Cades Cove, Great Smoky Mountains National Park
General Distribution: Moist woods and meadows. Massachusetts and Vermont to Michigan and Missouri, South to Florida and Louisiana.
Propagation Goal: plants
Propagation Method: seed
ProductType: Container (plug)
Time To Grow: 13 Weeks
Target Specifications: Stock Type: Container plug.<br> Height: 4-5" after cut backs.<br> Caliper: N/A.<br> Root System: Full, firm plug.
Propagule Collection: Collected in Cades Cove, Old Field by NPS staff on 11/4/99.
Propagule Processing: Seed Processing: Harvested by hand. In cleaning, the pappus is removed from the seed by a debearder modified by NPMC staff for small seed lots. For ease of cleaning, large seed lots are run through a large clipper before being further refined in a desk top clipper. Either machine will need a solid bottom screen and top screen with holes large enough for the seed to fall through. Fan speed is set low enough to blow only empty seed out.
Seeds/Kg: (100 seed weight was .05 g); about 3,900,000.
Germination: Not tested; around 17% of seeds planted germinated. (450 plugs per gram of seed)
Purity: 100%.
Pre-Planting Treatments: Seed Treatments: Seed trays were given a 3 week cool, moist stratification period in the NPMC cooler (@ 40§F, 35% relative humidity) as a precaution.
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: Hand sown in 406 cell germination trays.

Container Type and Volume: Seedlings were started in 406 germination plug trays and transplanted to Ropak multipots (67 cell).

Growing Media: Germination mix; Sunshine #1 plus Nutricote 180 day.
Establishment Phase: Sowing Date: Seeds were sown in mid-December, and stratified for 3 weeks.

% Emergence and Date: First emergence occurred 3 days after moving seed trays from cooler to bench.

Sowing/Planting Technique: 0.6 gram of seed and 6.0 grams of talc were mixed and sprinkled over the surface of germination media; drenched lightly with Triathlon fungicide at recommended rates. Trays were covered with clear plastic to seal in moisture and moved to cooler.

Establishment Phase: Seed trays were kept covered with plastic on greenhouse bench until germination occurred. Plugs were transplanted to multipots 4 weeks after the seed trays were moved to the greenhouse. Germination media was kept evenly moist while germinating.
Active Growth Phase: Rapid Growth Phase: Seedlings produced rampant, succulent growth requiring frequent cutbacks to keep plugs sturdy and open to air. Some die back and rot occurred in the center of several multipot plug trays and on lower foliage that stayed too moist or was not exposed to air.
Hardening Phase: Hardening Phase: Greenhouse temperatures were reduced and fertilizer stopped two weeks prior to outplanting. Plugs can also be moved outdoors to harden off in a sheltered location if frosts are not expected.
Harvesting, Storage and Shipping: Harvest Date: Plugs were outplanted by hand-dibbling in May.

Total Time to Harvest: 13 weeks from germination to finished plug.

Seed storage: Seed was sown immediately after collection and cleaning; remaining seed was stored in cooler at 40§F, 35% relative humidity.

Storage Conditions: Not over wintered.
Length of Storage: N/A.
Other Comments: E. muticum has the fragrance and rampant growth characteristics of the mints while under greenhouse cultivation. Spacing plugs out in propagation trays (i.e. using every other cell) may prevent center die-back caused by fungus.
References: Gleason, Henry A. and Arthur Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. p. 442

Citation:

Kujawski, Jennifer L.; Davis, Kathy M.. 2001. Propagation protocol for production of Container (plug) Pycnanthemum muticum (Michx) Pers. plants USDA NRCS - Norman A. Berg National Plant Materials Center Beltsville, Maryland. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/01). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.