Heuchera (micrantha)

Lee Riley Horticulturist USDA FS - Dorena Genetic Resource Center 34963 Shoreview Road Cottage Grove, Oregon 97424 541-915-7324 541-767-5709 (fax) lee.riley@usda.gov

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Family Scientific Name:	Saxifragaceae
Family Common Name:	Saxifrage
Scientific Name:	Heuchera micrantha
Common Name:	Crevice alumroot
Species Code:	HEMI7
Ecotype:	Mt Hood National Forest, Oregon
General Distribution:	USA: CA , ID , OR , WA Native Distribution: Inner coastal areas from central California to British Columbia and west central Idaho Native Habitat: Moist, wooded banks and rocks
Propagation Goal:	Plants
Propagation Method:	Seed
ProductType:	Container (plug)
Stock Type:	444 ml (27 in3) container
Time To Grow:	20 weeks
Target Specifications:	Stock Type: Container seedling Root System: Firm plug in container.
Propagule Collection:	Collect into paper bags
Pre-Planting Treatments:	Due to small seed size, the easiest method is to sow seed into trays filled with stabilized medium plugs (Q-plugs). Trays are sealed inside plastic bags and placed into refrigeration at 1 to 3 °C for 70 days. Trays are checked weekly and kept moist throughout the stratification period. If mold is evident, trays should be treated with 1% hydrogen peroxide.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Greenhouse growing facility. Q-plugs are lightly covered with nursery grit. Seedlings are transplanted to target containers approximately 3 weeks following removal from stratification. Growing medium used is 40:20:20:20 peat:composted fir bark:perlite:pumice with Apex controlled release fertilizer (16N:5P2O5:10K2O with minors; 6 to 7 month release rate at 21C) at the rate of 2 gram Apex per 444 ml container.
Establishment Phase:	Germination is fairly uniform and is usually complete in 2 to 3 weeks. Following germination (while still in Q-plugs), plants are fertilized with soluble 12-2-14-6Ca-3Mg at 75 to 100 ppm for 2 weeks.
Length of Establishment Phase:	2 to 3 weeks
Active Growth Phase:	Plants are somewhat slow-growing following establishment, but will rapidly fill the container and close canopy within 2 months. At that point, plants may have to be spaced out in racks to avoid drought in some containers. Soluble fertilizer (20-9-20 NPK, 20-18-18 NPK, or 17-5-24 NPK) at 100 to 150 ppm is applied weekly throughout the growing season.
Length of Active Growth Phase:	16 weeks
Hardening Phase:	No dry-down is done to induce dormancy. Seedlings are moved to an outdoor growing area in early September.
Length of Hardening Phase:	2 to 3 weeks
Harvesting, Storage and Shipping:	Harvest Date: Mid to late 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:	Alumroot plants are very susceptible to root weevils. It is recommended to treat plants with beneficial nematodes several times during the growing season.
References:	Dorena Genetic Resource Center Propagation Records, unpublished. Lady Bird Johnson Wildflower Center. nd. Heuchera micrantha Douglas ex Lindl. URL: https://www.wildflower.org/plants/result.php?id_plant=HEMI7 (accessed 8 Oct 2018). [NRCS] USDA Natural Resources Conservation Service. Heuchera micrantha Douglas ex Lindl. crevice alumroot. URL: https://plants.usda.gov/core/profile?symbol=HEMI7 (accessed 8 Oct 2018).

Citation:

Riley, Lee E.; Klocke, Allison. 2018. Propagation protocol for production of Container (plug) Heuchera micrantha Plants 444 ml (27 in3) container; USDA FS - Dorena Genetic Resource Center Cottage Grove, Oregon. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/04/21). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.