Asclepias (incarnata)

Lee Riley Horticulturist USDA FS - Dorena Genetic Resource Center 34963 Shoreview Road Cottage Grove, Oregon 97424 541-915-7324 541-767-5709 (fax) leriley@fs.fed.us

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Family Scientific Name:	Asclepiadaceae
Family Common Name:	Milkweed
Scientific Name:	Asclepias incarnata
Common Name:	swamp milkweed
Species Code:	ASIN
Ecotype:	Deschutes National Forest, Oregon
General Distribution:	Swamp milkweed is widely distributed across the U.S. and Canada from Quebec and Maine south to Florida and Texas and west to Nevada and Idaho
Propagation Goal:	Plants
Propagation Method:	Seed
ProductType:	Container (plug)
Stock Type:	262 ml (16 in3) container
Time To Grow:	16 weeks
Target Specifications:	Stock Type: Container seedling Root System: Firm plug in container.
Propagule Collection:	Collect seeds in the fall, when the brown pods are dry and have begun to split.
Propagule Processing:	Crack the pods open completely allowing the seeds to dry for one to two weeks in paper bags. Several weevil larvae prey on developing seeds, so look for signs of damage including small entry holes in the pod exuding latex
Pre-Planting Treatments:	Seeds are placed in fine mesh bags into a 1% hydrogen peroxide (3:1 water/3% hydrogen peroxide) soak for 24 hours, rinsed, and placed in water for an additional 24 hours. The bags are placed in sealed containers in refrigeration at 1 to 3 °C for 45 days. It is very important to check seeds weekly. If mold is evident, seeds should be treated with 1% hydrogen peroxide.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Greenhouse growing facility. Seeds are directly sown into containers. Seeds are lightly covered with nursery grit. Growing medium used is 40:20:20:20 peat:composted fir bark:perlite:pumice with Nutricote controlled release fertilizer (18N:6P2O5:8K2O with minors; 180-d release rate at 21C) at the rate of 1.5 gram Nutricote per 262 ml container.
Establishment Phase:	Germination is fairly uniform and is usually complete in 10 to 14 days. Following germination, plants are fertilized with soluble 12-2-14-6Ca-3Mg at 75 ppm for 1 week.
Length of Establishment Phase:	2 to 3 weeks
Active Growth Phase:	Seedlings grow rapidly throughout the active growth phase. During the growing season, fertilization depends on weather. Soluble fertilizer (20-9-20 NPK, 20-18-18 NPK, or 17-5-24 NPK) at a rate of 100 to 150 ppm is applied weekly throughout the growing season.
Length of Active Growth Phase:	14 weeks
Hardening Phase:	No dry-down is done to induce dormancy. Seedlings are moved to an outdoor growing area in early to mid September.
Length of Hardening Phase:	2 to 3 weeks
Harvesting, Storage and Shipping:	Harvest Date: Mid October Storage Conditions: Seedlings are usually outplanted in fall. No storage except in outdoor growing area. Plants are well irrigated prior to shipping and shipped in containers.
Other Comments:	Wetland classification: OBL Length of storage for seed viability has not been determined.
References:	Dorena Genetic Resource Center Propagation Records, unpublished. Kirk S, Belt S. 2011. Plant fact sheet for swamp milkweed (Asclepias incarnata). Beltsville (MD): USDA Natural Resources Conservation Service, Norman A. Berg National Plant Materials Center. URL: https://plants.usda.gov/factsheet/pdf/fs_asin.pdf (accessed 9 Oct 2018). USDA Natural Resources Conservation Service. Asclepias incarnata L. swamp milkweed. URL: https://plants.usda.gov/core/profile?symbol=ASIN (accessed 9 Oct 2018).

Citation:

Riley, Lee E.; Klocke, Allison. 2018. Propagation protocol for production of Container (plug) Asclepias incarnata Plants 262 ml (16 in3) container; USDA FS - Dorena Genetic Resource Center Cottage Grove, Oregon. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/04/24). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.